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Spring Garden Tasks for a Happy Garden

Amidst these very troubling and upsetting times due to the COVID-19 pandemic, I appreciate my garden even more. It is a refuge where I can go and clear my mind of all the chaos around me and feel some calmness. I can see the hummingbirds going for a meal in the flowers of Oregon grape (Mahonia aquifolium), and then fly off to a nest that is hidden someplace close. My dog Max, laying contently in the sun and watching me and the surroundings, adds to the respite. For Max and the hummingbird, this is just an April day in the garden.

To make the most of my garden through the growing season, I give it extra care in spring. These are the tasks that are certain to make my summer and fall garden the most enjoyable.

April Garden Tasks

Weeding and bed cleanup are two essential spring garden tasks.

Clean Up Beds: An April day in the garden to me is a signal that there is much yet to be done. Lots of tasks to be completed and this year, even pulling weeds seems much less of a chore than in past years. With the mild winter that we had, many marginally winter-hardy plants have survived and need to be cleaned up and prepared for warmer weather. Stems must be cut back, and old plant debris gently raked away.

Rejuvenate and Plant Outdoor Pots: It is also the time when I like to rejuvenate my many outdoor potted plants. If the pot is relatively small, I will probably remove all of the potting mix and add new. If it is a large pot, I will probably remove about half of the old potting mix and fill the rest of the pot with new. With the old potting mix that I have removed, I will apply this as a top dressing around established plants in the garden.

My potting mix of choice is Black Gold Natural & Organic Potting Mix, but this year several new potting mixes are being offered by Black Gold, which I am anxious to try, including Black Gold® Natural & Organic Flower and Vegetable Soil, which is specially formulated for contained flowers and edibles, and Black Gold Natural & Organic Ultra Coir, which holds extra water for longer. All of these products are OMRI Listed for organic gardening.

Pots of cheerful pansies are a sure sign of spring.

Plant Spring Pots: My smaller outdoor pots get planted with spring annuals. (Click here to learn more about spring containers.) I also pre-planted layered bulb containers in fall, which always look beautiful when they start to bloom in spring. (Click here to learn how to make layered bulb pots.) Once summer is around the corner, I trim away the fading bulb foliage and plant these containers with warm-season annuals for summer.

Some of my larger pots will be filled with perennials and maybe even a choice small shrub or two. In normal years, I enjoy visiting my favorite garden centers to find new and exciting plants, but under the current circumstances, I am looking for more plants online. Once the danger subsides, I will check to see if my local garden centers offer curbside pickup or delivery. Safety is more important than getting every garden plant on this year’s wish list.

Spring is a great time to divide perennials.

Divide and Plant Perennials: Plants that have overgrown their boundaries need to be divided and either moved or given away to friends (at a distance these days). Simply take a sharp space and divide and dig out unwanted clumps. Be sure to fill any holes with extra soil or amendment. If I can find some good new perennials for any holes in my garden, I also plant them at this time. It is always exciting to try new things and watch them bloom and grow.

Apply a layer of quality mulch to your garden beds before your perennials have fully emerged. It will save so much weeding time in summer.

Mulch: If you are going to add mulch to your garden, April is an excellent time. It is much easier to mulch now when plants are beginning to grow, rather than waiting until they have grown and filled in the empty spaces around them. The recommended depth for mulch is 2 to 3 inches because it is deep enough to stop weeds. Deeper mulch can smother or damage the emerging crowns of perennials or trunks of woody plants.  (Click here to read more about different mulch options.)

Mossy lawns are a common sight in the Pacific Northwest. If you dislike moss, spring is the best removal time.

Moss (or Other Weed) Control: Moss is often a reoccurring problem in Pacific Northwest lawns, and now is the time to apply a moss control product. Be sure to read the label of your moss control product because many contain iron, which will stain concrete areas as well as the shoes of the person applying it. Those with broadleaf weed problems in their lawns should apply corn gluten at this time to put a damper on them.

Raspberries are a good edible plant for yards, but they require regular pruning and training

Plant Edibles: There is a huge interest in planting edibles in the landscape, including cool-season vegetables that can be planted now. (Click here for a list of cool-season vegetables.) If you have a sunny location, consider planting some of the cane berries, such as raspberries or blackberries. There are even dwarf forms ideal for containers. (Click here to learn more about the Bushel and Berry® Collection.) Don’t forget about lowbush blueberries, which are tidy shrubs that are easily be planted in with ornamentals, or strawberries, which grow well in pots (Click here to learn how to grow strawberries). Blueberries also make good container specimens for a deck or patio; just make sure they have a partially sunny location. (Click here to read more about edible landscaping.) There are also loads of exceptional spring-flowering trees with edible fruit to consider planting. (Click here to read more about flowering fruit trees.)

My hardy banana stems will grow back quickly as the weather heats up. (Image by Mike Darcy)

Special Projects: Every gardener is going to have projects unique to their gardens. Several days ago, I had what I jokingly referred to as a Musa massacre. I have a large clump of hardy banana, (Musa basjoo). It is considered hardy, but that means it is root hardy, because if we have a cold winter, the huge banana leaves will be killed, and the plant will die to the ground. However, in the spring new ‘pups’, as they are often called, will appear, and these new plants will often grow to 8-10 feet in one season. With the mild winter we had, my plants did not die back, but with the cold and wind, the leaves were shredded, and the clump was not an attractive sight! I cut off all of the old leaves and then cut the main stalks back to 5-6 feet. It was a lot of work.

There is a lot to do in April, and despite the many tasks, I like to emphasize that gardening should and can be enjoyable. Don’t let the April tasks be overwhelming, especially now that so many of us have extra time on our hands. Even if your gardening space is limited, take advantage of what you have. Even with no outside gardening space, there is a new world of hanging baskets, window boxes, and house plants! (Click here to learn more about creating hanging baskets, and click here to see some of our favorite festive house plants.)

How to Amend Clay Soils

One of the garden necessities that should never be overlooked is having the right soil for the right plant, which often means having good, fertile loam. For our plants to perform at their very best, it is our job to give them the best soil we can, but clay soils can make this a challenge. The best time to thoroughly amend the soil for a garden plant is at the time of planting, which is why it pays to work hard to enrich clay garden soils from the start.

Clay Soil Properties

Clay tends to stay in large clumps that harden in the sun. Breaking them up and incorporating organic matter will help keep them porous and reduce clumping.

The mention of clay soil to many gardeners will probably make them shudder. I had a gardener once tell me that clay was meant for making pottery, not for growing plants! Clay soils are mineral soils with very small particles. These are generally low in organic matter and have very small pore spaces, making it difficult for plant roots to penetrate and gather needed air and water. That’s why too much clay in the soil can be a detriment to plant growth. Plant roots need a balance of air pockets (for oxygen) and available water, but in heavy clay soils, air pockets are very small and scarce. As water seeps into the fine pore spaces of clay soil, the spaces quickly become fully saturated, leaving no room for air, and water percolates or drains through the small pores very slowly. Many plants grow poorly in these soil conditions.

But, while a clay soil is often a curse to gardeners, it does have some benefits. Clay particles capture nutrients and ward off the loss of soil nutrients by leaching. It also holds water well, so amended clay can have good fertility and water retention capabilities. The key is physically breaking the clay up and mixing in large quantities of light, porous organic matter to create structural balance to support good plant health.

Clay Soil Amendment

Tilling clay soil is a great way to lighten its texture quickly.

For a home gardener with heavy clay soil creating a garden or planting in the landscape is a task. It is essential to work up and fortify the soil in all beds and planting areas. Clay soil is easiest to amend when it has a light amount of moisture and is easily dug. Work up the soil with either a tiller or use a spading fork to manually break it up as deep as you can–a depth of 1 to 2 feet is good, depending on what you are planting. As the soil is turned over and loosened, it is gaining air pockets. Expose the broken up clay to the sun and air for a while, then break it up further. Once the clay is as light as can be, it’s time to add lots of organic matter.

The addition of large amounts of organic matter will transform clay soil. Both Black Gold Peat Moss and Black Gold Garden Compost Blend will do wonders. Add these products to your gardens at a ratio of one part organic matter to two parts soil for lasting fertility. Be sure that they are well incorporated to help maintain air pockets and soil loft. These products will ‘open’ heavy clay soils, improve drainage, and allow water to move more freely. Once everything is incorporated, apply fertilizer as needed, and get planting.

Over time, organic soil amendments will break down. Adding Black Gold Garden Compost Blend, leaf mulch, or fine bark mulch to the top of the soil yearly will annually benefit soils and help maintain fertility. Treating clay soil is not a one-time ‘thing,’ but rather a continuous process with a top dressing applied at least once a year. Twice would be better. If you are amending a vegetable garden or other annual bed, add in a wealth of organic matter each year because vegetables are demanding crops.

Other Amendment Considerations

Vegetable gardens benefit from the yearly addition of lots of organic matter into the soil.

I have been fortunate in my garden and have not had to deal with heavy clay issues. Nonetheless, I always add some compost to new plantings,  in addition to mineral additives, like perlite and crushed pumice. I have found that these two products help with drainage and tend to keep the soil looser. Of course, container planting is much easier because plants are either planted annually or upgraded and transplanted regularly. No amendment needed.

Consider a plant’s basic requirements for optimum growth– air, water, nutrients, and a suitable environment. Highly fertile garden soil is one of these requirements. When you can provide the essentials, your plants will thank you!

Fertile garden soil that’s high in organic matter is porous, holds water and air well, and lets roots grow freely.

Late-Winter Garden Tasks for a Happy Garden

Clean off any debris that has collected on the lawn over the winter.

Take a Garden Stroll

With a steaming cup of coffee in my hand, I walk out into my garden this February morning and delight in seeing the nodding, bell-shaped white flowers of snowdrops (Galanthus nivalis) (Click here to learn more about other early spring bulbs like snowdrops). I have a bed of these early-blooming winter flowers that have naturalized in a shady area of the garden. They are among the first blooming plants of the year. I see a few weeds here and there and pulling them will be a task for later in the morning.

Stop and enjoy your earliest garden flowers and weed around them along the way.

Just beyond the snowdrops is a mass of hellebores (Helleborus hybrids) that have, over the seasons, re-seeded and naturalized (Click here to learn more about Helleborus). They are now in full bloom and make quite a showing in the winter garden. I thought that I had groomed them all in fall but realize that there is still more grooming to be done. The old leaves need to be cut off. It can be a delicate job because it is easy to cut a new flower stem or emerging leaf. It is just another task to complete before the month is over, and spring actually arrives.

Beds and plants need cleaning up, tools need care, and the lawn requires tidying. Here are all of the late-winter garden tasks that I undertake to get my garden space into gear for the coming spring.

Prepare Your Garden Tools

Sharpen, clean, and oil garden tools for the coming season.

There are a few, what I call “general preparative maintenance tasks” yet to be completed in late winter that I plan on doing soon. These include things such as getting the lawnmower tuned up, and the pruning shears and spades sharpened, cleaned, and oiled; it is nothing very exciting and rather mundane tasks to me, but once completed I will feel that I am ready to begin to garden.

Prune Roses

Prune your roses before they bud out.

Not that I believe that roses know the day of the month or when we celebrate certain holidays, but in the Pacific Northwest President’s Day has been the traditional time to prune roses. For hybrid tea roses, this is the time to remove any dead or dying canes. I like to thin my roses by taking out small and weak canes, so I am left with a bush that is about 18 inches tall with 4-5 sturdy canes. I also take off all of the old leaves on the ground and remove them from the area. The debris can harbor insects or diseases from the previous year, so it is important to remove all old plant material. It is also a good time to remove any weeds around the roses. (Click here to learn more about pruning shrub roses.)

Plant New Roses or Shrubs

Plant new shrubs. Make sure they are dormant or just breaking bud, like the other shrubs in your yard.

If you have some roses that have not performed well or perhaps were disease-prone, it is a good time to replace them. You can replace them with new choice shrubs or more disease-resistant roses. New bare-root roses start arriving at garden centers at this time, and the selection of varieties is probably better now than at any other time of year. Check the tags on roses as to their disease resistance properties. Since many of the new varieties have been bred to be disease resistant, this should be noted on the label. At planting time, be sure to amend the soil with Black Gold Peat Moss. (Click here to learn more about organic rose care and planting.)

Cut Back Old Perennials

Cut back the stems from last year’s perennials, such as peonies, making sure not to damage any newly emerging stems.

If you have not cut your herbaceous peonies back to ground level, do it now, and be very careful not to accidentally cut any of the new stems that are emerging from the ground. Remove the old stems and any leaves left from last year as old peony leaves can carry several diseases that can infect new growth in the spring. Keep the area around peonies free from any debris. This cutting-back process should be done with all other perennials that have old, dead leaf material from the previous year.

Prune, Clean, Plan New Plantings

Prune, clean, and prepare a tidy space for spring flowers to emerge and new plants to be planted.

You may have heard many gardeners say that a garden is never complete because there is always something else that needs to be done. In my garden, I can certainly attest to this. As I look around, I see some shrubs and small trees that need some additional pruning. Then there are the pathways in the garden that need to be re-defined and the brick edging that should be re-worked. I also like to take this time to think about what plants need to be removed or transplanted. Some gardeners refer to this as ‘editing’ because there is always something that is in the wrong place or has grown too large and needs to be divided. For most plants, February is still a good time to transplant.

As I gaze over my garden, I am already thinking of what new plants I will be buying in the spring and what new combinations I will have in my many pots. We have recently had some much-needed rain, and I am thrilled that my soil is having rain penetrate into the root zone of many plants. While I am not quite ready for spring, I will welcome its arrival and will hopefully have my late-winter tasks completed.

Late-Winter Garden Task List:

  1. Clean and sharpen spades, pruners, and other tools
  2. Cut back old perennials
  3. Divide and move perennials that have grown too large
  4. Get lawnmowers and other gas-powered equipment serviced
  5. Plant shrubs
  6. Prune roses, shrubs, and trees
  7. Rake up any leaves and debris that have blown into the lawn
  8. Remove winter weeds
  9. Repair heaved or damaged garden walkways
  10. Stop and admire your emerging garden

Award-Winning Flowers for 2020

Echinacea Sombrero® Baja Burgundy (Image by AAS Winners)

The beginning of the year is always filled with award shows to highlight the best-of-the-best. In the entertainment industry, there are the Oscars, Grammys, Emmys, and Tony Awards. In the horticultural world, there are All-America Selections, Fleuroselect, RHS Award of Garden Merit (UK), and other more regional awards for the best-of-the-best garden plants. Plant introductions that receive awards are marketed as having better flowers, stronger stems, disease resistance, unique foliage, and different growth habits. Overall, they are somehow improved or different relative to what is already on the market. Growers and garden centers then sell winning plants to lucky gardeners.  The following is a small fraction of new or notable plants that have received some kind of award for 2020.

All-America Selections Winners

Tip Top Rose nasturtium (Image thanks to All-America Selections)

One of the most active organizations for plant trials and awards is the All-America Selections (AAS). Founded in 1932, it has introduced award-winning annuals, perennials, and vegetables ever since. Its mission statement is, “To promote new garden varieties with superior garden performance judged in impartial trials in North America.” The AAS has about 200 display gardens coast to coast, which include those in public botanical gardens, arboreta, retail garden centers, university gardens, and municipalities.  Where I live in Oregon, there are AAS display gardens at Clackamas Community College in Oregon City, Oregon State University Extension Service in Redmond, and Territorial Seed Company in Cottage Grove. Most states have comparableble publically accessible AAS trial gardens.

Thus far, 2020 has given us three new AAS award-winning flowers. These are Sombrero® Baja Burgundy coneflower (Echinacea Sombrero® Baja Burgundy), Tip Top Rose nasturtium (Tropaeolum minus ‘Tip Tip Rose’), and American Gold Rush black-eyed-Susan (Rudbeckia ‘American Gold Rush’). (Tip Top Rose nasturtium also happens to be a 2019 Fleuroselect winner.)

Sombrero® Baja Burgundy coneflower has deep violet-red blossoms and makes an excellent cut flower. It was trialed over three tough winters, and the AAS Judges noted that was a standout for hardiness, heavy flowering, and showed very sturdy branching. All coneflowers (Echinacea spp.) are good wildlife plants that attract many pollinators and seed-eating birds.

Tip Top Rose nasturtium, another AAS winner, is a compact, bushy bedding plant with rose-colored flowers that rise above the green foliage. The flowers do not fade as they age, and the strong, uniform plant continues to flower well through the season. Nasturtiums are also excellent choices for pollinator gardens, and both the leaves and flowers are edible. (Click here to discover more edible flowers).

Fleuroselect Winners

Silene ‘Sibella Carmine’ (Image thanks to Fleuroselect)

Fleuroselect is another plant trial and award organization that is international but based in Europe. The current membership is comprised of about 75 bedding-plant breeders, producers, and distributors with a goal of evaluating new bedding plants and contributing to the development and advancement of the industry as a whole. Two promising Fleuroselect Gold Medal Winners for 2020 are Shasta daisy Madonna (Leucanthemum x superbum ‘Madonna’) and nodding catchfly Sibella Carmine (Silene pendula ‘Sibella Carmine’).

Fleuroselect refers to ‘Madonna’ one as the next Shasta daisy star. Unlike most other Shastas, it reblooms. The easy-care perennial forms new flowers over the fading ones and blooms from summer to early autumn. It looks good in pots and containers as well as beds and landscape areas.

When spilling from a hanging basket or pot, ‘Sibella Carmine’ looks spectacular. It bears loads of reddish-purple, semi-double flowers that bloom all season and don’t require deadheading. This is one that will most certainly become a common sight at garden centers across the country. It requires regular moisture to perform to its fullest, so I recommend planting it in Black Gold® Moisture Supreme Container Mix for best success.

Oregon Association of Nurseries’ Winners

Hibiscus moscheutos Summerific® Evening Rose (Image thanks to Proven Winners®)

On a more local level where I live, the Oregon Association of Nurseries (OAN) has its list of winners. Every August, the OAN has a large grower-oriented trade show called the Farwest Show, which Black Gold attends every year. Within the show, there is a section called New Varieties Showcase where growers feature some of their best new plant introductions. This is one of my favorite areas to visit at the show, and I always learn about new plants on the market. Show attendees vote on their favorites, and winners are selected and given an Award of Merit.

Last year, one of my favorite plants from this display was the hardy hibiscus Summerific® Evening Rose (Hibiscus moscheutos Summerific® Evening Rose), which won an Award of Merit. This hardy hibiscus has bright rose flowers and near-black foliage. Hardy hibiscus is becoming more popular in our area, and I now often see it in gardens. They are easy to grow, prefer full sun, and bloom late in the season, giving the late-summer and autumn garden a splash of color.

All of the plants mentioned should be available at garden centers this spring. Many will have special tags to let potential buyers know that this plant has been selected for an award. Award-winners are a safe choice for gardeners looking for something sure to perform beautifully. I always like to try new plants in my garden each year and with offerings like this, my list for 2020 continues to grow.

Click here to read more about award-winning annuals that you can grow from seed.

Hellebores for Late Winter Color

It has been unseasonably cold here in the Pacific Northwest. In Portland, Oregon, we have had temperatures down in the teens, which is not the norm. To make matters worse, we had an extended period when the temperature did not get above freezing. The ground is very dry, which causes additional stress on plants when the ground is frozen. Walking out into my garden this morning, I must say it is looking very bleak. The Eugene area has had some snow, which is a good insulator that offers cold protection for plants, but the Portland area has not had any significant snow. Our ground is bare and dry. Nonetheless, the hellebores are beginning to show themselves.

However, we have many benefits to be living and gardening here, and one is the hellebore (Helleborus spp.), which is a true winter gem. Most are hybrids of the winter-blooming Christmas Rose (Helleborus niger) and later, midwinter- to early spring-blooming Lenten rose (Helleborus orientalis). All can withstand the cold, wind and rain and not only survive, but thrive. It is also one plant that I have heard deer will not eat. Hellebores were very popular in the Midwest in the early 1900s, and then their popularity diminished. In the early part of this century, they made a resurgence and have become increasingly popular in Pacific Northwest gardens. Plants are being bred to have stronger stems and an ever-increasing palette of color.

 

The Best Hellebores

Hellebore 'Double Painted'
The glorious hellebore ‘Painted Double’ is one of many outstanding selections in the Winter Jewel™ Series.

Hellebores should be on every gardener’s must-have perennial list. Their most outstanding attribute is that they bloom in winter when most other perennials are sleeping the deep sleep, but their evergreen foliage is also a nice, year-round bonus. When planted in masses, they even make a nice groundcover. Even novice gardeners will find these shade-lovers easy to grow. They’re even deer-resistant.

As I write this column in early December, there are flower buds beginning to show their color on some of my plants. I have seen hellebores even blooming in the snow in January. A particular variety that has been outstanding in my garden, called ‘Jacob Classic’,  is from the Gold Collection®. This is an early bloomer with white flowers that tend to face forward instead of downward, as many Hellebores do. It will begin flowering in January and continue for at least two months. It makes an excellent container plant, especially by an entryway, as the early blossoms provide winter cheer.

Another group of hellebores is the Winter Jewel™ Strain. The flowers in this series provide some apricot, yellow, white, and rose-red bloom colors that are relatively new for hellebores. I have two of these that have performed will in my garden and provide some striking winter color. These are ‘Painted Double’ and ‘Golden Sunrise’. As the name implies,  ‘Painted Double’  has double flowers of white with rose-red speckles that look painted. The cheerful ‘Golden Sunrise’ has ruby-edged single flowers that turn slightly downward to reveal the soft yellow backside of the petals.

Growing Hellebores

Hellebore 'GoldenSunrise'
Ruby edges bring radiant color to the nodding, primrose-yellow flowers of hellebore ‘Golden Sunrise’.

 

Hellebores like to be planted in soil that is rich in compost, such as Black Gold® Garden Compost Blend. They also perform better when given some shade from the hot afternoon sun. Hellebores make excellent plants for under a large tree where they can benefit from the filtered light that falls from between the branches. Once established, they can become a permanent part of the garden and require very little maintenance.

Hellebores aside, many Pacific Northwest gardeners successfully grow plants that are considered marginally winter hardy. With our past relatively mild winters, many have survived with minimal protection. This winter is sure to prove which plants are marginally winter-hardy and which are not. In my garden, I have a Gunnera tinctoria that I consider marginally winter hardy. Luckily, several weeks ago, I mounded the crown with Black Gold Garden Compost Blend, and then on top of that I placed the huge Gunnera leaves that I had removed from the plant. The Gunnera leaves will help keep the conditioner from blowing away in the wind. Hopefully, this method will provide the insulation the plant needs to survive. I have done this in winter’s past, and it has worked.

Hellebore 'Jacob'
Clear white flowers with bright yellow stamens grace hellebore ‘Jacob Classic’ in winter.

With the weather as cold as it’s been, there is not much a gardener can do to protect plants without a protective greenhouse or sunroom, though I always have a few tender plants that I put on a garden cart and take into my unheated garage. (My prediction for this spring is that garden centers will see a surge in sales when spring finally arrives with gardeners buying plants to replace those that couldn’t take the cold.) In the meantime, get into the spirit of this season with a visit to your garden center, and check out the holiday displays, which are certain to include a few choice hellebores.

Colorful Flowering Kalanchoe for Winter Cheer

Do you seek a cheerful holiday plant that will look good in your home all season long? One of the best is the succulent flowering kalanchoe (Kalanchoe blossfeldiana, USDA Hardiness Zones 10-11). Unlike the top-selling poinsettia, it is tough, easy to grow, and always looks good.

Garden sticklers (like me) like plant names to be pronounced correctly, and kalanchoe is not exactly an easy name that rolls off the tip of the tongue. The correct pronunciation is /ka·luhn·koe·ee/, however, it is often incorrectly pronounced as the name looks, /ka·lan·choe/. Regardless of how it is pronounced, it makes a very colorful indoor plant for the high holidays.

The Kalanchoe Calanday® Dendi has prolific, bright red flowers.

Flowering kalanchoe is a classic holiday plant in Europe, but it is less so in the United States. It’s hard to understand why. The tough succulent from Madagascar makes an attractive, long-lived house plant with robust clusters of starry, four-petaled flowers that come in a variety of colors, with red and white being most popular at this time of the year. (Flowers are also available in shades of purple, pink, yellow, and orange, and double forms are popular.) Plants are forced into bloom in winter, but they naturally flower in spring, so expect a new flush later in the season. During the rest of the year, enjoy their attractive large, glossy leaves with scalloped edges.

As a house plant, flowering kalanchoe has another distinction. It is featured in NASA’s 29 best air-purifying house plants. I did some checking on this list, and even though it does rank at #28, it made it!

Four Beautiful Flowering Kalanchoe Varieties

Flowering Kalanchoe in the Calendiva® Series are double and flower densely.

The most common and best of the kalanchoe on the market are bred in the Netherlands by the company Dümmen Orange. They breed high-performing plants with dense flower clusters in a wide color range. The most famous varieties include those in the Calandiva® Series, which have large, heavy blooming clusters of fully double flowers that come in many shades (the Grandiva® Series is similar but flowers are larger). Compact plants in the Calanday® Series are very densely branched and flowered. Plants in these series are some of the easiest to find at nurseries and greenhouses, and they all make excellent house plants.

Flowering Kalanchoe Selection and Care

This holiday display of flowering Kalanchoe in Europe illustrates its seasonal popularity there.

For the longest length of bloom select plants that have tight flower buds or are just starting to open and show some color. Those purchased at this stage will often continue blooming for up to eight weeks. The healthiest will have many glossy, undamaged leaves.

Because they originate from the tropics, flowering kalanchoe will not survive a winter outside unless you live in southern Florida or southwestern California. Give them plenty of bright sunlight from a south-facing window in winter, but when taken outdoors in summer direct sun can burn their leaves, so choose a spot with bright shade.

Water lightly in the winter. Wait until the soil is dry to the touch, usually after 7-10 days. Often plants will have a foil wrapper around them, so be sure to remove that when watering. Water them in the sink, and let the excess water drain before putting the foil wrapper back around the plant. Place a dish at the base for safety. In spring and summer, plants will dry out more quickly and require more frequent watering.

Propagating Flowering Kalanchoe

Some particularly beautiful varieties are worth propagating.

Kalanchoe is very easy to start from cuttings. This is a good learning tool for children because of the leaves root quickly and are fun to grow. Cut a stem 4-5 inches long, and after cutting let it lay on a paper towel for several days until the cut end seals over. Then place the cutting in a small pot with Black Gold® Perlite. It will root in no time and start to grow! Have your child pick a pretty, well-drained pot for it, fill it with Black Gold® All Purpose Potting Mix, plant it, give it good care, and watch it bloom and grow.

So, when you purchase a colorful flowering kalanchoe, remember it has multiple uses. Enjoy the colorful flowers it can bring into a home on a dreary winter day. With little care, these plants will continue to flower for many weeks. It also makes a delightful host/hostess gift. Don’t overlook this plant at other times of the year as well.

Favorite Oregon Grapes for Landscape and Garden

A well-established Oregon grape looks spectacular in full fruit.

It was not too many years ago that gardeners often thought of Oregon grape (Mahonia aquifolium, syn. Berberis aquifolium) as primarily a woodland plant that did not belong in the ornamental garden. This Pacific Northwest native, which is the state flower of Oregon, is a member of the barberry family. Whereas Oregon Grape does not have spines like barberry, the plants do have spiny leaves–one of the reasons home gardeners avoided them. But, times change, as do trends, whether with regard to plants, fashion, or whatever the commodity. As for mahonia, there has been a resurgence of it in gardens.

Mahonia Landscape Traits

Brilliant bursts of yellow flowers are the crowning glory or Oregon holly in spring. (Image by Mike Darcy)

Oregon grape’s evergreen leaves are deep green, compound (leaves with multiple leaflets), and sometimes turn red or bronzy shades in winter. The common name refers to the attractive clusters of grape-like blue berries that appear in the fall. While these berries are edible, they are not particularly tasty when eaten directly off the plant, but they are quite good in jams and jellies. They are also an excellent food source for wild birds.

Attractive flowers are another attribute that makes Oregon grape a desirable garden plant. Most forms have brilliant yellow flowers borne in rounded, dense, spiky clusters that provide a very bright spot of color in the garden. In the Pacific Northwest, these bloom in late winter. In other areas of the country with colder winters, they tend to bloom in spring. On the West Coast, the flowers are a valuable source of nectar for hummingbirds as well as bees.

Once established, Oregon grapes require little care and minimal supplemental water. Protect the shrubs from bright sunlight, whether in summer or winter, to prevent leaf sunscald. While I have never heard of them being referred to as invasive, they do spread by underground stems, and in some states where they are not native, they have naturalized into the wild.

Mahonia Varieties

The variety ‘Soft Caress’ has soft, palm-like foliage.

Different species and new cultivars on the market have different heights and textures, giving gardeners new design options. When visiting a garden center, you may be surprised by the many cultivars available. Those living in the Pacific Northwest have even more varieties from which to choose. Our many specialty nurseries carry species and cultivars that are not always easy to find elsewhere. Regarding the selections mentioned below, I have tried to maintain a list of plants readily available at local garden centers across the country.

Oregon grape (Mahonia aquifolium, USDA Hardiness Zones 5-8) is an evergreen woodland shrub found in coniferous forests and open woodlands from British Columbia down to northern California, primarily on the western side of the Cascade Mountains. Dark, evergreen leaves, which are spiny and holly-like, look beautiful year-round. The dense, bushy shrub can reach 6-12 feet in height. Clusters of tiny, bell-shaped flowers of bright yellow flower from late winter to spring. Bluish berries mature by fall and may persist into winter.

Charity Oregon grape (Mahonia x media ‘Charity’, Zones 6-9) is a hybrid that has become very popular with gardeners due to its more delicate evergreen leaves and extra-large, prolific sprays of yellow flowers. It is a tall plant, reaching 8-15 feet in height, so it needs plenty of space in the garden. It makes an excellent background plant in a shrub and perennial border.

Creeping Oregon grape (Mahonia repens, Zones 5-8) only reaches about 1-3 feet in height and makes a good woodland ground cover. It can take sun but also deep shade and is drought tolerant once established. It is native from the Pacific Northwest down to West Texas, so drought tolerance and bloom times vary. In the North, it tends to bloom in late winter, but further south if produces small, rounded, tight clusters of yellow flowers as late as early summer. Its deep green, holly-like foliage turns reddish hues in winter. It is an easy-care, low maintenance plant that is often overlooked as a ground cover.

Soft Caress Oregon grape (Mahonia ‘Soft Caress’, Zones 7-9) is a relatively new hybrid mahonia on the market, and, as the name implies, the almost palm-like, evergreen foliage is soft and thornless. The growth habit is such that it is compact enough to be planted in containers and also makes an excellent border plant. Its yellow flowers appear in late winter to early spring and dark blue fruits mature by fall. This mahonia needs extra shade and protection from high winds, so plant it in a sheltered spot away from the hot afternoon sun. It reaches a height of about 3 feet and requires little supplemental water once established. I have found that when gardeners are first introduced to ‘Soft Caress’, they are amazed to discover it is a mahonia.

Mahonia Care

The evergreen leaves of Oregon grape can turn shades of red and burgundy in the colder months.

All mahonias grow best in soils that are fertile, very well-drained, and slightly acidic. At planting time, fortify their soil with Black Gold Peat Moss, which is slightly acid and an excellent source of organic matter. Provide them with partial sun to shade for best growth, flowering, and fruit set. These are true forest shrubs that dislike harsh winds that will desiccate their foliage. All-day winter sunlight can also scorch the leaves, so plant them where they are shaded for at least part of the day.

Oregon grape was once relegated to native and woodland gardens but has now become a mainstream garden plant for many good reasons. It is easy to grow and has bright winter flowers that provide food for hummingbirds and bees at a time when few other plants are blooming. Moreover, once established, most forms require little supplemental water. Visit your local garden center to see its spectacular, leaves, berries, and flowers for yourself. You’ll want to buy one right away!

The blueish berries are edible when ripe but are better left to birds. (Image by Mike Darcy)

Overwintering Outdoor Ceramic Containers

With 150+ potted containers throughout my garden, it is important that I overwinter them well. Living on the relatively mild western slope of Oregon’s Willamette Valley, our winters do not compare with those in colder parts of the country, but we do get freezing temperatures. Almost every winter, we will have some nights when the temperatures dip into the low 20’s and sometimes into the high teens. While we also have our fair share of rain during the winter months, we often get a few days of snow and ice, which can wreak havoc on containers.

Protecting Wintering Containers

This snow-covered Italian Terracotta flower pot will likely weather through the winter.

Plants in containers are exposed to the elements more than those in the ground. Pots do not offer roots as much insulation or protection, but each is different in its protection and durability, whether glazed ceramic, concrete, plastic, Terracotta, or stone.  (In this article, we will cover ceramic pots, which are what I use.) Just like the hot summer sun can quickly dry soil in a container, especially with Terracotta pots, cold temperatures, and winter wind can freeze the soil. The ice expands, and as it does, it often has enough force to crack certain pots, especially if the soil is moist.

The question is, what ceramic containers endure winter cold without cracking? In our climate, it would be very unusual for a container not to have soil wet from the winter rain and then potentially freeze. So, having the right container is an important necessity.

Over the years, I have learned through trial and error what pots work. The conclusions that I have reached are not scientific but based on my own experience in dealing with different types of pottery from different places. Some behave poorly outdoors and are better reserved for indoor plantings.

Pots for Indoor Use

Mexican pottery is fantastically pretty but cracks easily outdoors in freezing winters.

First, bear in mind that some manufacturers add elements to their clay to make pots more winter hardy, and some don’t. Thickness and firing temperature can also help prevent cracking. Generally, I have found that Terracotta-based Mexican pottery, glazed or unglazed, will not survive a cold winter without cracking. Likewise, most pottery from China is variable, but the thin pots tend to crack. Some of the most beautiful pottery that I have seen is from Thailand, but it tends to be thin-walled and is poor for outdoor planting.

Thin-walled ceramic pots tend to crack while thicker-walled pots don’t.

We do have some pots from Thailand in our garden, though. These tend to have unique designs and colors and create much interest from visitors. We use Thai pots as pieces of garden art with nothing planted in them. There are holes in the bottom for the rain to drain through, so there is no concern about cracking.

If you choose to grow summer annuals in pots that are not reliably frost-proof, take out the soil when you remove the annuals. Or, if your containers are mobile, move them into a garage to protect them.

Pots for Outdoor Use

Thick-walled, high-fired Vietnamese pottery survives the winter very well for me.

Containers from Italy seem to go through our winters just fine, but those that consistently weather through without cracking are from Vietnam. In our area, the Vietnamese pots sold in local garden centers are thick-walled, highly glazed and fired, very heavy, and frost proof. I have some pots from Vietnam on our deck that we have had for 15 plus years, and they have never cracked. These pots are exposed to winter winds, rain, freezing; they have no protection from the elements.

Thick, high-fired Italian pottery also withstands winter cracking better.

Another important factor when a purchasing pot is getting the right pot for the right location. Check the selection of winter-hardy pots at your local garden center for colors, sizes, and styles with good thickness, high fire, and thick glaze. I have found that the right colorful containers scattered throughout the garden are permanent additions that also serve as garden art.

Microclimates play a role, too. Try to protect your outdoor pots through winter by placing them below overhangs or patios close to the house. Not only can this further help protect them from cracking, it helps the shrubs or perennials they hold.

Ginkgos Large and Small

In Portland, Oregon, Ginkgo biloba trees line the streets in an area called Park Blocks. These magnificent trees were planted years ago and today reach a height of perhaps 100 feet.  The Ginkgo is an excellent choice for a large street tree when taking into consideration the ultimate growth expected.  (Large tree lawns are a must.) They do not seem to be bothered by insects or diseases, are tolerant of air pollution and most soil conditions, and they provide shade in the summer and beautiful golden fall leaf color in the autumn.

Ginkgo History

An allee of ginkgos creates a spectacular fall display.

I have long been fascinated by these historic trees and marvel at their survival instincts.  Ginkgo fossils exist dating to over 270 million years old. At one time they were thought to have grown worldwide, but presently, remnant populations were found to only exist in China and Japan. Throughout Asia, these trees were revered as fixtures in temple gardens and Buddhist monasteries.

Ginkgo trees are monoecious, a technical term meaning that separate trees have either just male or just female flowers. It may take a tree 20 years or more before the flowers develop.  When purchasing a Ginkgo, select male plants, (grafted or grown from cuttings), because female trees produce messy, fleshy, ill-smelling fruit. In Asia, they use the fruits of the female trees for medicinal purposes, but they are not of value to most homeowners.

Ginkgo Size

Many ginkgo varieties have narrow, upright habits and no messy fruit.

There are several lovely large- to medium-sized ginkgo varieties. Most have been chosen for their unique, appealing growth habits in addition to robust growth and vigor. Those used as landscape trees are always seedless males. Two of the better available selections include the narrowly columnar ‘Princeton Sentry’, which only reaches 40 feet by 15 feet, and the excellent street tree ‘Magyar’, which reaches 50 feet x 25 feet and has a narrowly pyramidal shape with branches that curve upwards.

In my garden, I do not have space for a 100-foot or even a 40-foot tree. Most homeowners do not.  However, due to recent ginkgo introductions, there are some cultivars that I can and do grow.  Sometimes these are sold as being compact or “dwarf,” but it appears that the word dwarf often refers to a slow rate of growth rather than a small ultimate size. The plants might not be “dwarf” as we perceive the word to mean.  I have been growing these new dwarf cultivars in pots and have them throughout my garden.  With their slow rate of growth–even slower in a pot–they are easy to manage, and some selective pruning will keep them at the size that I want. (Ginkgos are classic trees for bonsai, so they are amenable to hard pruning.)

 

Dwarf Ginkgos

The leaves of the compact ‘Majestic Butterfly’ have beautiful variegation. (Image by Mike Darcy)

At the top of my dwarf ginkgo list would be the variety ‘Majestic Butterfly’.  It is the first dwarf that I purchased, and it continually attracts the most attention from visitors.  The annual rate of growth is considered 5-7 inches, so it has been very manageable.  The outstanding feature of this ginkgo is the striped green and yellow variegation on the leaves, though the color can be variable. Sometimes an all-green branch will pop up, but as it goes through the season, the variegation will appear.

Another favorite isMarieken’.  It was discovered as a sport mutation in Holland in 1995 and is now in the retail trade.  In my garden, it has a semi-prostrate growth habit.  I have pruned it in such a way to encourage this habit, and it is now a spreading shrub of about 2 feet high and 6 feet wide.  The leaves have wavy ruffled edges and turn brilliant gold in the fall.

The dwarf ginkgo ‘Mariken’ is a bushy, spreading beauty.

The ginkgo ‘Jade Butterfly’ has proven to be quite popular with gardeners and should be readily available at nurseries.  It has dark green leaves that look similar to the wings of a butterfly.  It is another excellent ginkgo for a pot, and the unusual looking leaves draw much attention.  As it matures, it develops a shrubby, vase-shaped habit.

The Ginkgo’s Legacy

Ginkgos have long been used for bonsai and can withstand the harshest treatment.

With fossils dating the ginkgo back millions of years, the endurance and survival of the ginkgo was ultimately tested when they dropped the atomic bomb on Hiroshima in 1945.  Within days after the explosion, three Ginkgo trees sprouted new leaves.  These trees were the closest survivors to ground zero after the atomic blast.  Today they are part of the Hiroshima Peace Memorial Museum, and former Director Akihiro Takahashi summed it best when he declared that the ginkgos “expressed the endurance of hope, the need for peace and reconciliation.”

My Favorite Summer Flowering Trees

With the proliferation of spring-flowering shrubs and trees, sometimes the trees that flower in the summer can be overlooked.  This is too bad because there is quite a selection of summer flowering trees from which to choose.  Many people visiting our garden are often surprised to see the trees that are in bloom in July and August.  So, as people visit our summer gardens, we make sure to educate them about our favorite summer-blooming trees.

Crepe Myrtle

Standard-sized crepe myrtles develop fine, vase-shaped habits.

One of my favorite summer blooming trees is crepe myrtle (Lagerstroemia indica).  Perhaps thirty years ago I planted one of these small, multi-stemmed trees in my garden and at that time it was not a well-known tree in the area.  It has since thrived and is now about 20 feet tall.  It blooms in August and continues flowering into September with flowers that are pale lavender.

Truly, it is the terminal clusters of small, curly edged, brightly colored flowers of white, pink, red, or lavender that really make these trees shine. But, crepe myrtles have many other desirable attributes.  The leaves are often tinged with red when they open in the spring and then turn dark green as they mature.  The bark is another outstanding feature. As the trees mature, the smooth grey or tawny bark begins to exfoliate, revealing a lower layer of copper-colored bark.  The bicolored effect is especially attractive in winter. Plus, many crepe myrtle trees have beautiful fall leaf color of red, orange, and/or yellow.

There is one common problem that these trees may have. That is powdery mildew. While the tree in my garden sometimes gets powdery mildew, many of the new hybrids are powdery mildew resistant. Trees planted in open areas with a lot of airflow and sunlight are also let apt to get the disease. Trees also perform best in very well-drained soil. The addition of Black Gold Garden Compost Blend will increase fertility and drainage.

The bark of ‘Natchez’ crepe myrtle looks beautiful any time of year.

For many years, the U.S. National Arboretum has conducted a breeding program and introduced many crepe myrtle trees and dwarf shrubs that have been selected for winter hardiness and mildew resistance.  Many of the mildew-resistant introductions have Native American names, such as ‘Zuni’ (bright purple flowers and orange-red to maroon fall leaves), ‘Tonto’ (semi-dwarf, fuchsia-red flowers, and orange-red fall leaves), ‘Hopi’ (semi-dwarf, pink flowers, extra attractive bark, and brilliant fall leaves in fiery shades), and ‘Natchez’ (white flowers, extra attractive bark, and orange-red fall leaves), and are exceptional performers in the garden. These new cultivars come in many sizes and have a wide selection of flower colors to choose from including white, red, pink, and various shades of lavender.

More recently some crepe myrtle plants have been developed for their intense black-purple foliage.  Examples are Black Diamond® and Sunset Magic. Check with your local garden center to see if any of these beautiful selections are available.

Seven Son Flower

Seven son tree has fragrant, white flower clusters in summer.

The Chinese seven son flower (Heptacodium miconioides), is an easy-to-grow, summer-flowering tree that we do not often see, probably because it is not well known.  The common name, seven son flower, is named for how the flower clusters are arranged. Smaller whorls of seven small flowers comprise the larger flower clusters. The flowers appear over a long period in the summer, from July to August, and are ivory and fragrant. They are followed by masses of attractive small fruits that appear inside rose-purple calyxes. From a distance, these calyxes look as though the tree is flowering.

There is one seven son flower in my garden that receives minimal care and still performs well. This tree can reach 15 to 20 feet tall and 10 feet wide and be trained as a single or multi-trunked specimen. The leaves are glossy green and the bark exfoliates, which is an added feature.

Harlequin Glorybower

The colorful fruits of harlequin glory bower are almost as pretty as its flowers.

When the harlequin glorybower (Clerodendrum trichotomum) blooms in my garden the fragrance of the flowers is almost intoxicating.  Flowers appear in late July and August in white clusters.  This tree also has the common name of peanut butter tree because when the leaves are crushed they have a peanut butter scent.   This tree has fruits with scarlet edges that develop metallic-looking turquoise centers that will often last until after the leaves fall in autumn.  It is quite a sight to see these colorful fruits on bare branches.  This tree does sucker, so beware and remove suckers as soon as they appear.

Golden Rain Tree

The papery pods of golden rain tree are unusual and attractive in their own right.

If you have more space in your landscape, the midsummer-flowering golden rain tree (Koelreuteria paniculata) is a great choice. When mature, the trees reach a stately 30 to 40 feet–not too big and not too small. Airy clusters of golden flowers cover the tree when in bloom and are followed by interesting, drooping papery pods that are attractive in their own right. The tree’s compound leaves add textural interest and turn shades of gold, orange, and red in fall. Look for the variety ‘September’, which flowers later, from August to September.

This list offers just four examples of attractive summer-flowering trees.  For more selections, visit a local arboretum.  Many local garden centers will also have other suggestions for sale and are an excellent local source of information.  Don’t think that flowering trees are only for spring.  Extend your bloom season into summer and sometimes even into fall.

The white summer flowers of harlequin glory bower are in attractive clusters.