Articles

What Do I Need To Grow Container Vegetables?

“I am starting a container garden for onions, potatoes, and carrots. I will be using the Black Gold potting mix plus fertilizer. Will I have to add any other product to the potting mix? Thank you.” Dennis of Thaxton, Virginia

Dear Dennis,

Potted vegetables grow best in large containers filled with excellent potting soil,  like our Black Gold mixes, and quality fertilizer formulated for vegetables. Be sure that the containers drain well, and keep them evenly moist. Full sun exposure is a requirement. This is about all that you need. Thin your carrot as they grow, and space your onions and potatoes well. I also recommend that you read these articles about growing edibles in containers. We have many, many more on the site.

Happy gardening,

Jessie

Outstanding Cannas

Every summer I plant my favorite Canna standby, ‘Striata’. It is the perfect floral backdrop for other bright garden flowers. (Image by Jessie Keith)

Cannas are summer-garden workhorses. They grow lushly in the hottest months, only requiring regular water, partial sun, and maybe a hit of slow-release fertilizer at the beginning of the season. Their leaves are bold and lovely, their tropical flowers come in lots of warm pretty colors, and hummingbirds are prized pollinators. The plants also spread and are easily divided and shared. My garden will never be without one.

Canna Origins

Hummingbirds love visiting all canna blooms!

Cannas (Canna hybrids, Zones 8-11) are subtropical to tropical and American. There are 12-21 accepted species, depending on who you reference. These are found in Mexico, Central America, the Caribbean, and tropical South America. The common garden type is Canna × generalis, a hybrid of several species. They were cultivated by native Americans, presumably for both their attractive flowers and fleshy, edible roots. In the late 1900s, cannas were popularized in European and then North American gardens. Since this time, many attractive hybrids have been developed, with new varieties appearing now and then.

Ten Favorite Cannas

Red-flowered cannas, like ‘Kreta’, are sure to attract hummingbirds.

Alaska‘ (3-4 feet): Large cream-colored blooms are the great beauty of this compact canna, and its blue-green foliage is also respectably pretty. It gets all-around rave reviews.

Australia‘(4-5 feet): Large red flowers and big bronzy-purple leaves make this impressive canna a standout. If you are looking to fill a large space with lots of reliable color, this is your canna. It contrasts well with orange- and yellow-flowered plants.

‘Alaska’ is a compact, cream-colored canna.

Cleopatra‘ (4-5 feet): Expect explosive fireworks of color with ‘Cleopatra’. Its impressive green leaves have irregular blocks of dark purple. These are in stark contrast to its flowers, which are half red and half yellow with red spots. Expect it to receive many compliments.

Kreta‘ (3-4 feet): Here is a great canna for nonstop flowers. Its numerous red blooms are prolific and attract lots of hummingbirds and rise above large green leaves.

Musifolia‘ (6-8 feet): This old canna variety is grown for its tall stature and impressive large leaves with hints of red and purple. In the height of summer, it will also offer spikes of small red flowers.

Phasion‘ (syn. ‘Durban’ and ‘Tropicanna’, 3-4 feet): Most regard this as the most electrifying of all cannas. Few garden plants can challenge its impressive tropical palette of colors. Its striped leaves alone are a masterpiece, and its brilliant tangerine-orange flowers add the winning touch.

Striata‘ (syn. ‘Praetoria’, ‘Bengal Tiger’, and ‘Aureostriata’, 5-6 feet): My garden is never without a ‘Striata’ for summer color. Its pale-yellow striped leaves provide a more neutral backdrop for the light orange flowers it produces from midsummer to frost in my area.

Toucan® Coral is a beautiful compact canna from Proven Winners®. (Image thanks to Proven Winners®)

Tenerife‘ (3-4 feet ): Big golden flowers speckled with deep orange-red make this an extra lovely compact canna. Its leaves are medium green.

Wyoming‘ (3-4 feet): I always confuse ‘Wyoming’ and ‘Australia’ because they are comparable in every way except flower color. This one has beautiful orange flowers to offset its purplish-bronze foliage.

Toucan® Series (Scarlet, Yellow, Dark Orange, Coral, 2.5-4 feet): Toucan cannas are big bloomers on short-statured plants. They come highly recommended for containers. Expect them to perform beautifully all summer long.

Canna Care

Canna rhizomes are easy to plant, dig, and divide.

Cannas are lush, tropical to subtropical perennials that grow best in the full to partial sun. They thrive in rich moist to average soils–the addition of organic matter at planting time is recommended. Black Gold Garden Soil is a great choice. Provide a boost of continuous-release fertilizer formulated to encourage good growth and flowering. They originate in warm, humid, rainy areas and appreciate regular water. Many even grow well along pond margins or boggy spots. When conditions are warm, they will flower. If they are not hardy where you live, dig their dense, fleshy rhizomes in the fall and store them in a cool, dark place through winter. Plant them again outdoors when the soil has warmed and frosts are gone.

Canna Yellow Streak Virus

Several viral diseases will put a damper on canna growth and flowering. The two most common are the canna yellow streak virus (CaYSV) and the canna yellow mottle virus (CaYMV). Infected plants show abnormal leaves with browning or yellowing streaks or mottled patterns. If your canna leaves exhibit these, dig and dispose of them immediately. When replacing them, buy only certified virus-free stock (specialty growers are usually the most reliable source). Be sure not to reuse the potting soil, if your diseased plants were in containers.

Native Spring Flowering Trees For Bees

When flowering trees bloom, they are a boon for pollinators, particularly bees of all sorts. They bloom en masse for a week or more, offering a lot of essential food with little forage. There are no better plants to boost these essential pollinators in the garden, and the native trees here feed for both our honeybee friends as well as native bees.

Spring Flowering Trees For Bees

The trees in this collection vary in size from small to large. All are beautiful in their own right, and most grow and flower best when grown in the full sun. Soil and moisture requirements vary. If any of these trees interest you, I recommend reading this article about how to site and plant a new tree, by Russell Stafford.

Red maple flowers give the trees a reddish caste in the spring. (Image by Famartin)

Most do not realize that the early spring flowers of red maple (Acer rubra, Zones 3-9, 40-70 feet) are essential early food for honeybees and native bees (Red Maple (Acer rubrum L.), an Important Early Spring Food Resource for Honey Bees and Other Insects, 1985). Their small masses of red flowers appear before the leaves emerge in late winter or early spring and provide winter-weary bees needed pollen and nectar. The lovely eastern-native shade trees cool and beautify large landscapes all summer long, and their leaves turn shades of red, orange, and yellow in the fall. They grow well in open, sunny areas in dry uplands as well as moist lowlands.

The new leaves of downy serviceberry are covered with down and emerge after the white flowers that attract bees. (Image by Dcrjsr)

The delicate white flower clusters of the eastern North American downy serviceberry (Amelanchier arborea, Zones 4-9, 15-30 feet) also provide early-spring food for lots of bees, especially small native bees (mostly mining bees and sweat bees). Its new leaves emerge after the flowers and have downy hairs on them, which explains the common name. In summer, the edible summer fruits are a favorite of many fruit-eating birds, and the fall leaves turn brilliant shades of orange, red, and yellow. Some gardeners like to collect the ripe serviceberries for fresh eating, jam making, or pies. Though the multi-stemmed tree grows well in forests, it develops its finest habit, fruits, and flowers when grown in the full sun.

Redbuds are extra lovely trees for bees.

Eastern redbuds (Cercis canadensis, Zones 4-8, 20-30 feet) bloom for one to two weeks in the mid-spring with bare branches laden with lots of tiny, purplish-pink, pea-like blooms that glisten in the sun. Bees can’t get enough of them. Once the flowers of these eastern North American natives cease, the large, heart-shaped leaves unfurl. Sometimes they are reddish or purple as they emerge. Lots of small, thin pods follow the flowers, which turn from green to papery brown before they split open and release their seeds. The fall leaves turn humdrum shades of yellow. The fast-growing trees tolerate partial shade but perform best in the full sun and fertile to average soil. There are lots of great specialty redbud varieties from which to choose with variously colored leaves and flowers.

The fragrant, white flowers of fringetree draw many bees.

A native of the southeastern United States, white fringetree (Chionanthus virginicus, Zones 3-9, 12-20 feet) has fine, fringed, white flowers that are fragrant and almost exclusively bee-pollinated. They bloom for several weeks in May and June. Fleshy fruits that turn from green to blue-black follow, which feed many bird species. The small trees develop a pleasing rounded canopy and have green lance-shaped leaves. Expect the leaves to turn yellow in the fall.

Newer green hawthorn varieties lack the thorns of the wild trees. (Image by David Stang)

Green hawthorn (Crataegus viridis, Zones 4-8, 20-35 feet) is a handsome small tree from the eastern United States whose copious clusters of white mid-spring flowers attract lots of bees. In the fall, the glossy green, toothed leaves turn attractive red and purple hues, which look striking against the bright red fruits that cover the branches and are retained into winter for birds to eat. The branches of wild specimens have thorns, but some varieties, such as the popular ‘Winter King‘ have few thorns, while also offering more flowers and brilliant-red fall fruits. The newer variety Crusader® is equally beautiful and totally thorn-free.

The attractive nectar guides of catalpa flowers are like beacons to bees.

The large, lush, copious flower clusters of the northern catalpa (Catalpa bignonioides, Zones 4-8, 40-60 feet) bloom in the late spring. The fragrant flowers have maroon and yellow nectar guides designed just for bee pollination, so the insects know where to land and gather nectar and pollen. Large, elongated pods follow the flowers. Its large, elongated/oval leaves turn yellow shades in the fall. The only downside of these easy-to-cultivated trees is that their fruits are messy, and the trees live for only around 60 years. Still, they have high wildlife value and beauty. If you have a spacious yard, plant them where they can be enjoyed but won’t be a bother. These trees naturally exist across the southeastern United States and tolerate average to moist soils.

The large, flattened flower clusters of nannyberry attract many insect pollinators. (Image thanks to USDA-NRCS)

It’s always nice to add a real pollinator generalist and Nannyberry (Viburnum lentago, Zones 2-8, 18-25 feet) is a very good one. It is a small tree, unlike most other viburnum species, which are shrubs.  Its flattened clusters of ivory flowers appear in mid to late spring, and they are pollinated by bees as well as other insects. The caterpillars of the spring azure butterfly feed on the summer leaves. Edible black fruits and bright red or orange leaves comprise its fall show. Birds eat the nannyberries and disperse the seeds, but the sweet fruits are also edible to humans as well as other wildlife. Nannyberry tolerates moist soils or those with average drainage.

Why Aren’t My Black Mulberries Blooming?

“I purchased two mulberry bushes from Baker Creek [Heirloom Seeds] several years ago (Morus nigra). Neither of these has bloomed yet, and I would like to know how long it takes for them to fruit.  There were 2 plants to the offer.  They have grown well and are healthy.” Question from Carla of Birchwood, Tennessee

Dear Carla,

Age is most likely the problem. On average, a non-grafted black mulberry can take up to 15 years before flowering and producing a big crop of fruit, but don’t let this worry you. I understand that the Dwarf Black Mulberries sold from Baker Creek Heirloom Seeds are on dwarfing rootstock that encourages earlier flowering and fruiting. You will likely see some of its small, inconspicuous flowers in as little as three years, possibly four. They bloom in May or June and the summer fruits quickly follow, so this may be the year! Just be sure to feed and water the trees well and provide them with plenty of sunshine. The addition of quality compost to the soil can also encourage good growth. Our premium Natural & Organic Garden Compost Blend is OMRI Listed for organic gardening and works wonders. Ace sells it online. Give it a try.

Have a great gardening season!

Jessie Keith

Black Gold Horticulturist

How Do I Germinate Guayacan Seeds?

“I have tried unsuccessfully to germinate seeds “Lignum Vitae”. I have asked the grower what to do and followed their guidance…..any suggestions?” Question from Eddie of Chula Vista, California

Dear Eddie,

The Caribbean tree-of-life or guayacan (Guaiacum officinale (syn. Lignum vitae), Zones 10-12) is rarely grown in the US. In my experience plants of tropical origin with large seeds have a short life and germinate quickly where native. Getting fresh seed of Guaiacum officinale just off of the plant will likely be a challenge because it is hard to find. If you do find fresh seeds, then a pre-treatment is needed to get them to germinate:

I also found another article about starting the seeds (Click here to read the article.) You can try buying the seeds once more if you can find a fresh source that can be shipped quickly. Another option is to buy a plant. There are online sources, though they are uncommon: https://rebrand.ly/Guaiacum-for-sale. I hope that this information helps.

Happy gardening,

Jessie Keith

Native Violets For The Garden

Halberd-leaf yellow violet (top right), Canadian violet (bottom right), Labrador violet (bottom left), and bird’s foot violet (top left)

Last spring I visited the Smokey Mountain National Park during high wildflower season, and I was struck by all of the unusual, beautiful native violets there.  All had a delicate beauty suited to woodland and shade gardens. I started looking for garden center availability and was struck by the many North American violets available to native gardeners. Most are perennial, but a few survive as spring annuals.

Violets and Wildlife

‘Freckles’ is an uncommonly beautiful common violet. (Image thanks to Baker Creek Heirloom Seeds)

Overall, our native violets are easy, pretty, and have a place in the garden. In fact, they support wildlife more than most might think. Even the native common blue violet (Viola sororia, Zones 3-9), which gardeners often weed from their beds and lawns, are beautiful and feed the larvae of many species of fritillary butterflies, which are close relatives of monarchs. According to the Xerces Society, a whopping 14 species of greater fritillaries (Speyeria spp.) and 16 species of lesser fritillaries (Bolloria spp.) lay eggs on common violet leaves for their caterpillars to feed upon, develop, and grow.  The fragrant flowers, which have bee nectar guides and are largely pollinated by native bees, are also visited by butterflies. Some native bees are even specialized for Viola flower pollination, such as the violet miner bee (Andrena violae).

Most fritillaries are orange and black. Different species have different pattern markings and ranges.

For these reasons, they are worth leaving alone in lawn areas or other places in the yard. Let them sow and spread freely where they do not compete with other garden plants. If you don’t have common violets in your yard, a good garden variety to try is the beautifully speckled ‘Freckles‘. My mother started it from seed over 25 years ago, and they are still beautiful in the garden! The flowers look very pretty clustered in small bud vases.

Six Beautiful Native Violets for the Garden

Most native violets grow best in fertile, moist soil and partial sun to shade. They also tend to spread, some slowly and others more quickly. They make fine garden perennials, especially for more naturalistic beds. Any exceptions to these rules are noted.

My favorite native violet is the bird’s foot violet, which has large 1.5-inch flowers and fine foliage.

When researching these native violets, I quickly found that all native American violets feed numerous native bees and play larval host to many fritillary species–too many to be mentioned by name. Lots of American fritillaries are threatened or endangered, so maintaining a few native violets in your yard is important! It is also important to source nursery-grown stock or seeds rather than plants collected from the wild. (Click here to learn more about avoiding poached, rare plants.) All seed and plant sources provided here are legitimate.

Labrador violet is often evergreen to semi-evergreen and has purplish-bronze foliage.

Canadian violet (Viola canadensis, Zones 2-8): These hardy perennial violets can reach up to 12 inches and produce lots of white or pale-violet spring flowers that stand tall above the large, heart-shaped leaves. It makes a pleasing native groundcover for moist woodland or shade gardens and is native across much of central and northern North America, extending far into Canada. Expect Canadian violet to self-sow and spread naturally to create a seasonal native groundcover for the shade.

Halberd-leaf yellow violet (Viola hastata, Zones 5-8): Though rarely sold in commerce, at all but the most select native plants sales hosted by native plant societies, Halberd-leaf yellow violet is one of the prettiest of all native woodland violets. Its attractive leaves have silvery markings and sunny yellow flowers are produced in the spring. The woodland native is found in old woods across the eastern coastal United States. If you can find it, grow the 4-8-inch plants in a moist, shaded garden spot.

American dog violet (Viola labradorica, Zones 2-8): Just look at that hardiness zone! This little 3-6-inch violet has native populations that extend into the farthest north reaches of eastern Canada, and it is so lovely. Its low-growing bunches have purplish-bronze, heart-shaped leaves as well as royal-violet-purple flowers in the spring and summer. It is evergreen to semi-evergreen, making it an excellent small-scale groundcover violet for the full sun to partial shade.

Smooth yellow violet is a sweet little yellow-flowered species for shaded gardens.

Bird’s foot violet (Viola pedata, Zones 4-8): I love this unique violet for its fine foliage, which resembles little green bird’s feet, and wide, violet-blue flowers punctuated by orange eyes. They are found in old, established sandy woodlands across eastern North America. Expect the 1.5-inch flowers to appear from spring to midsummer. They will tolerate full to partial sun. Well-drained soil and regular moisture are required. The 3-10-inch plants do not tend to spread.

Prairie violet (Viola pedatifida, Zones 3-7): The sun-loving little prairie violet is native across the prairie lands of Central North America and spreads less aggressively than average violets. Its bright violet-purple flowers look pretty against the delicate, cut-leaf foliage. Unlike most violets, prairie violet will tolerate drier soils. Flowering occurs from mid-spring to early summer. Sometimes it will rebloom later in the season. Plant the 6-inch violets along garden edges where they can slowly self-sow.

Smooth yellow violet (Viola pubescens var. eriocarpa, Zones 3-7): Here is a pretty yellow-flowered violet that grows best in shaded, moist, eastern North American woodlands and gently spreads. Expect it to produce little yellow blooms from mid-spring to summer. Standard Viola pubescens has downy rather than smooth leaves.

Starting Native Violets From Seed

Violet seeds are easily collected or available for sale.

These perennial violets are most often sold from seed, so they are not expensive to grow. Most take a year before flowering from seed. We recommend sowing the seeds in flats of quality potting mix, such as Black Gold Natural & Organic Potting Mix, outdoors in the fall. This method, called moist outdoor seed stratification (click here for stratification guidelines), lets them experience the winter moisture and cold, which many violet seeds need to germinate. When grown by this method, they often sprout in the late winter or spring.

Other Violet Uses

Violets serve other useful purposes in the garden. The flowers are edible, and their fragrant blooms have been used to make perfume over the ages. One common old-fashioned use for the flowers was to candy them. The sugar-crusted violets hold their color, are tasty, and look beautiful for decorating cakes and cookies. (Click here for a good candied-violet recipe.) The flowers can also be used to make a delectable, violet-blue simple syrup that can be added to mixed drinks and lemonade. (Click here for a good violet simple syrup recipe.)

If you have lots of common violets in the yard, try making candied violets.

How Do You Save Heirloom Pepper Seeds?

“I would love advice on saving seeds off of heirloom bell peppers.” Question from Shelby of Greenleaf, Idaho

Dear Shelby,

You are in luck! Peppers are some of the easiest seeds to save because they are dry, rather than fleshy, fruits with open interiors. What is important is waiting until the fruits are ripe to harvest the seeds. Green peppers have immature seeds that will not germinate. Once the fruits are fully colored and ripe, the seeds will be ripe.

Collect the seeds, place them in a labeled packet, and store them in a cool dry place through winter. I generally start my peppers in late winter or spring, at least eight weeks before the last frost date.

Please watch the video below for tips about how to grow peppers organically!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do I Maintain My Overgrown Potted Eucalyptus?

“Our Eucalyptus tree is at least 25 feet tall with no sign of slowing down. Could we lovingly remove it to maybe a better area? It is cold outside, and she just grows in all weather and doesn’t intend to be stopped. She is as high as our two-story home, and can’t support her upper branches.” Question from Philip of Lancaster, Alabama

Dear Philip,

You have two options. First, you can try finding a beautiful spot where it can be planted. It should be a beautiful tree if it will survive in your climate, and it sounds as though it will. Many eucalypts will grow well down South. Clearly yours is one. In general, they are tolerant of many different types of soil as long as they drain well. Full sun is a requirement.

Another option is to cut it back severely to encourage shrubby growth to reduce its size and upgrade its pot. This will allow it to remain as a container plant for a while longer. We recommend a very large pot because these trees need space. Fill the pot with a quality, fast-draining mix, such as Black Gold Natural & Organic Garden Soil or Black Gold Natural & Organic Potting Mix combined with quality topsoil at a 1:1 ratio. Cut back the dominant branches to the base of the trunk to lighten the branch load, and cut medium branches back by half. The best time to prune Eucalyptus is in the summer. They will drip some sap, but they heal faster when it is warm. I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Can You Force Daylilies for Indoor Enjoyment?

“My mother is ill and can’t get out of the house. She misses her garden, especially her daylilies. Would it be possible for me to move some of these into pots and have them thrive indoors? If so, any special care for them? Thank you!” Question from Jenifer of Saint Petersburg, Florida

Answer: We are so sorry to hear that your mother is ill and hope that she recovers soon. Daylilies (Hemerocallis hybrids) are hardy, summer-flowering perennials that grow best outdoors. They can, however, be forced to bloom early, so you could force some for indoor enjoyment for several weeks or more. Another option is to look for blooming specimens at local garden centers to bring to your mother. If you cannot find any, then try forcing your mother’s daylilies. Here are some recommendations.

Daylilies For Forcing

Most daylilies can be forced, especially newer, reblooming varieties. Because the plants will be potted and you want flowers fast, avoid forcing tall or late-blooming daylilies. Stick with compact, early, heavy-flowering types. The time it takes to force flowers varies from variety to variety.

How to Force Daylilies

We gathered this information from Greenhouse Product News magazine, which is for professional growers. Here is a shortened version to better help home gardeners force daylilies if desired.

  1. Larger clumps will produce more flowers, so start with a good-sized clump (perhaps 5-6 inches across at the base) that is either dormant or recently leafed out. Make sure that all of the roots are intact.
  2. Pot the daylily in a medium-sized pot with drainage holes at the bottom and a saucer to catch water. Be sure to cover the roots and leave the shoots or buds above the soil surface. Plant the daylily in quality, well-drained potting mix, such as Black Gold All Purpose Potting Mix.
  3. Water the pots in until water drains out of the bottom. Keep the soil lightly moist, never saturated.
  4. Daylilies are day-neutral plants that like lots of sunlight. High-intensity light will encourage them to bloom fastest and encourage full growth, so place them in the sunniest window of the house. You may need to provide supplemental grow lights if you lack a sufficiently sunny window.
  5. Cool growing temperatures help daylilies bloom faster. The article author, Paul Pilon writes: “In these trials, reducing the temperature from 75° F to 60° F increased the time to flower by eight to 15 days for most cultivars. I recommend growing daylilies at 65° F in environments with high light intensities for best results.”
  6. Plants take several weeks before growing full and budding out.

I hope these tips help. Start by contacting local garden centers to see if they offer blooming plants. Some may even be able to order flower daylilies for you. If not, now you have another option.

All the best,

Jessie Keith

Black Gold Horticulturist

What Is The Best Potting Mix for Potted Shrubs?

“I will be planting shrubs in containers. Which potting mix between Fafard and Black Gold would be the best choice and longest lasting? I would prefer something more permanent so as to not have to change out the potting mix every few years. I live in zone 7. Thank you for your response.” Question from Mel of Atlanta, Georgia

Answer: When recommending the best soil for potted shrubs that will be there for the long term, I always suggest filling the pots with 1/3 quality topsoil or ground soil and 2/3 quality potting mix. Mix the two evenly before filling the pots. I like to add ground soil because potting mixes tend to acidify over time, and ground soil, which is primarily inorganic, helps buffer the acidification process, and it will not break down and shrink over time. You might also consider adding some other ingredients, such as sand or pebble, depending on the shrubs grown. Finally, be sure to refresh the pot with new potting mix seasonally. The addition of dolomitic lime can also reduce acidification.

With that said, I would choose the following mixes for long-term potted shrubs.

Feed your shrubs seasonally in the spring with a slow-release fertilizer. It is also important to note that potted shrubs are most apt to survive winter if they are at least two zones hardier than your zone because they are more exposed.

All the best,

Jessie Keith

Black Gold Horticulturist