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Beautiful Buckeye Trees for Yard and Garden

The flowers of Aesculus x carnea may be pink or red, depending on the variety.

Probably known to many, the state tree of Ohio is the Ohio Buckeye (Aesculus glabra, 20-50 feet, USDA Hardiness Zones 3-7), a large tree native across eastern North America. Another common name is horse chestnut, a name that refers to its round, inedible, husked nuts with a mahogany sheen. In general, Aesculus trees are striking flowering specimens that come in a wide range of sizes and forms. In the Portland, Oregon area, mature specimen trees are most often seen in an arboretum or park setting. I also see them in older gardens with large lots suitable for big trees.

Species are variable, so it is important for homeowners to know about them before choosing a garden variety for the yard. Some are relatively small, while others are large and would overwhelm many garden spaces. When these trees come into flower, they put on a show that is spectacular. The flowers are largely bee-pollinated, but hummingbirds, moths, and even butterflies will also visit them. Exceptions are noted.

Five Beautiful Buckeyes

California buckeye is noted for its drought tolerance and large candles of summer flowers.

California buckeye (Aesculus californica, Zones 7-8) is a spring-or-summer-blooming California native favored for low-water gardens. The multi-stemmed tree only grows to 20 by 20 feet and has many large, palm-shaped leaves with multiple leaflets. The glory of this tree is its large spikes of cream-colored, fragrant flowers. They rise from the branches like candles from a candelabra. One important note is that the flowers feed native moths and bees, but non-native honeybees are another story. Apparently, the flowers produce a toxin that negatively impacts the growth and development of honeybees, so refrain from growing it, if you live near beehives.

A tough nature is a good reason to grow this buckeye. It is native to the Sierra Nevada foothills where it grows along dry slopes. In the wild, it naturally drops its leaves in mid- to late-summer to ward off severe late-summer drought. In a garden setting, the leaves will remain until fall with moderate irrigation.  The California Buckeye creates an attractive winter silhouette with its silvery trunk and stark branches.

Common horse chestnut is a popular European landscape tree that has escaped in some northern areas of the US.

Common horse chestnut (Aesculus hippocastanum, Zones 4-7) and is native to Europe. It is a very large, single-trunked tree that can reach 60 by 40 feet and bears large, ivory flower spikes in late spring that are pollinated by bees. Be aware that not only is its billowing crown massive, but the roots can also be very dense and tend to break up paved surfaces, so don’t plant it near a sidewalk, driveway, or in a typical city lot. The cultivar ‘Baumannii’ has large white flower panicles and does not set seed. This non-invasive variety is the preferred choice for US gardens.

Ohio buckeye has variable spring flowers that feed bees.

Ohio buckeye (Aesculus glabra, Zones 4-8) is a mid-sized (50-60 feet), single-trunked tree that is widespread across eastern North American.  Its spiked clusters of spring flowers may be in shades of pale green, yellow, or ivory with touches of red or pink. Hummingbirds and a wide range of bees pollinate the flowers. The green, palmately compound leaves turn shades of yellow or red in the fall. A variety for reliably red fall color is Early Glow™ Ohio buckeye. It is also disease-resistant and produces little fruit, which reduces fall mess.

The hummingbird-pollinated scarlet buckeye is the smallest (and arguably) prettiest of all.

The southeastern native scarlet buckeye (Aesculus pavia, Zones 4-8) is a spectacular, small (12-15 feet), multi-stemmed tree with loose spikes of tubular scarlet flowers adapted for hummingbird pollination. The huge flower spikes look impressive for three weeks or more in spring. Through summer, the tree’s large, green, palmately compound leaves are textural and pretty. When summers are dry, the foliage may drop as early as the first week of September. The stark branches and gray bark of the tree look pleasing through winter.

‘Briottii’ is electrified by bright, showy pink spikes of early summer flowers.

The red horse chestnut (Aesculus x carnea ‘Briotii’, Zones 5-8) is a cross between the European common horse chestnut and the American scarlet buckeye. It is a real show-stopper in full bloom with large, beefy flower spikes of deep pink or red. These appear in early summer and can reach up to 10 inches long. It is a relatively compact tree that should not reach more than 30 or 40 feet at maturity, so homeowners with modest-sized yards can consider growing it. An open lawn will show off its features best. Grow it now only for the flowers and the large leaves but for the winter bark as well.

If there is an arboretum or a large park near you, check out their list of trees to see if Aesculus specimens are listed. That way, you may be fortunate enough to see a couple in full bloom before potentially choosing one for your own yard.

[Click here to learn everything that you need to know about how to plant a new tree.]

Early Glow™ Ohio buckeye has reliably red fall color, unlike some other species that lack fall color.

 

 

What Is the Best Mix for Potted Citrus Trees?

“What is the best potting mix for Meyer lemon tree in a plastic pot?  Needs to drain well.” Question from Polly of New Mexico

Answer: We offer several good-fit mixes. Before potting your tree, make sure that the new pot is several inches larger than the old and that it offers excellent bottom drainage. The ideal potting soil should have a balance of good porosity, drainage, and water-holding ability. Ideally, it should be slightly acid, because Meyer lemons grow best in soils with a pH of 6-7. Here are our best OMRI Listed soils for your tree.

  1. Black Gold Natural & Organic Potting Mix
  2. Black Gold Natural & Organic Ultra Coir
  3. Black Gold® Natural & Organic Flower and Vegetable Soil

Growing Potted Citrus

Potted citrus trees require a minimum of 8 hours of sunlight a day to perform well. Warm growing conditions (60 – 75 degrees F) and moderate humidity (45 – 50%) will encourage flowering and fruiting. Bringing plants outdoors in summer, on a sunny porch or patio, helps them grow better year-round.

Good watering, feeding, and care practices will keep your plant happy. Water plants deeply until the water drains from the bottom of the pot. Allow pots to become moderately dry between watering–the tops should be dry down to a minimum of 3 inches. (Outdoor plants may need to be watered almost daily, while indoor plants require less frequent water.) During the winter months, when growth naturally slows, the watering regime should be reduced. Signs of overwatering include leaf yellowing and drop and eventually stem death. Trees allowed to become too dry may also unexpectedly drop some leaves.

Fertilization is essential, any slow-release fertilizer formulated for citrus would be ideal.

I hope that these tips help!

Jessie Keith

Black Gold Horticulturist

How Do You Get Grass to Grow in Shade?

“How can you grow grass when you have so many trees you get no sunlight on the ground?” Question from Terry of La Place, Louisiana

Answer: Sadly, the best thing to do is to grow something else. Grasses are notoriously sun-loving and none of the common lawn varieties will grow well in deep shade. Beds of attractive, low-growing groundcovers for deep shade are a much better choice. Some options are even grass-like, such as sedges. Here are some of the finest groundcovers for deep shade in Louisiana. You may even mix these up to create a more textural, interesting planting.

Southern Groundcovers for Deep Shade

Ajuga is an easy-to-find, spring-blooming groundcover for deep shade.

Partidge berry and little brown jug are my favorites because they are native, cute, tough, and feed wildlife. There are also lots of ferns to consider if the soil is not too dry beneath your trees. These include wood fern (Thelypteris kunthii) and Autumn fern (Dryopteris erythrosora).

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Magnificent Magnolias for Majestic Spring Flowers

Saucer magnolia is one of the most popular magnolias grown and blooms beautifully in early- to mid-spring,

I will always remember the early spring day in the 1960s when I exited the freeway into a wooded neighborhood and first saw saucer magnolia saucer magnolia (Magnolia x soulangeana, 20-25 feet, USDA Hardiness Zones 5-9, a cross between M. denudata x M. liliiflora) in full bloom. It was a spectacular introduction to the genus Magnolia.

Since that day, my interest in magnolias has not diminished and actually continues to grow each spring. In my own garden, I have several and would have more if it were not for space limitations. I regularly visit our local arboretum, the Hoyt Arboretum of Portland, Oregon, in the spring to see the Magnolia collection. There are also several area private gardens with extensive plantings of Magnolias, and I am a regular visitor.

About Magnolias

Saucer magnolias are large, long-lived trees that develop elegant branching with age.

Generally, magnolias are not small trees. Most of them will reach at least 25 feet and many have broad branches. Roger Gossler, of Gossler Farms Nursery in Springfield, Oregon, has an extensive display garden of magnolias, and he told me that he has consistently asked the hybridizers to please breed magnolias that are smaller because many of today’s customers are looking for trees in the 10-15-foot range. (The classic varieties in the Girls magnolia group, bred at the National Arboretum, have many smaller trees with fantastic blooms, but several are no longer on the market, and there is always a need for great new varieties for smaller gardens.)

Magnolia ‘Ann’ is a National Arboretum intro in the Girls series that reaches 10-12 feet tall.

For choosing the best Magnolias for your particular area, check varieties that local garden centers are offering. I also think that one of the best tests for specific varieties is to see what other gardeners are growing where you live. Be sure that they are reliably hardy where you live and not susceptible to early cold snaps in your area, which are known to sometimes freeze the spring buds and flowers.

Most Magnolia’s will grow in a full sun location but many also benefit from some protection from the hot afternoon sun. They like organic-rich and well-drained soil. The addition of Black Gold Garden Compost Blend would be ideal at planting time, and a yearly top-dressing is also beneficial. Magnolia roots tend to be fleshy so transplant them carefully while being sure to lightly tease apart any dense, pot-bound roots.

My Favorite Magnolias

Star magnolias are some of the first flowering trees to bloom with their starry pink or white flowers that appear before the leaves.

There are so many different varieties of Magnolias, and I am only able to list a very small number of them here. As I mentioned earlier, check to see what your neighbors are growing or local garden centers are carrying. It’s a great way to ensure that the trees you plant will grow well in your garden.

Yulan magnolias are fragrant and goblet-shaped.

One of the earliest blooming magnolias, which I have in my garden, is star magnolia (Magnolia stellata, 15-20 feet, USDA Hardiness Zones 4-8). This is one of the smaller growing types, my plant is probably 20 years old and perhaps 10 feet tall. The fragrant white flowers are small, 3 inches across, and appear on the stems before the leaves. The plant is a profuse bloomer and is covered with flowers in late winter.

Another that I have in my garden is Yulan magnolia (M. denudata, 30-40 feet, Zones 6-9), which has fragrant, ivory, goblet-shaped flowers that are 4-6 inches across and open before the leaves appear. Often a few flowers will appear during the summer. A bonus with this tree is that in late summer, red cone-like fruits appear and from a distance look as though the tree is in bloom.

‘Elizabeth’ has unique, pale yellow flowers.

Yellow is a rather elusive color in magnolias and ‘Elizabeth’ (15-30 feet, Zones 5-9) has set the standard since it was introduced and patented by the Brooklyn Botanic Garden in 1977. It has light yellow, fragrant flowers that are 6-7 inches across and often appear before the leaves. Another yellow is M. ‘Butterflies’ which is similar but has smaller, (3-4 inch) flowers.

I would be remiss without mentioning the one that, when in bloom, attracts the most attention in my garden. Magnolia ‘Black Tulip’ (15-20 feet, Zones 5-9) has one of the darkest blooms of all the hybrids. As the name indicates, tulip-shaped flowers that are very dark purple-red appear on stems before the leaves. This makes a spectacular display.

Here I am offering just the tip of the iceberg of available Magnolia selections. I have only mentioned some of those that bloom in early spring, but there are plenty of other varieties that bloom in summer, such as southern magnolias (Magnolia grandiflora) and Virginia magnolia (Magnolia virginiana), so don’t stop with spring!

‘Black Tulip’ is a unique hybrid with very dark, tulip-shaped flowers.

How Do I Manage Codling Moths on Fruit Trees?

 

“I have a Liberty apple tree and a peach tree within 20 ft of each other and every year fruit tries to grow but what I believe is the coddling moth destroy it all. Do you have an effective solution?  Sprays have not helped.” Question from Ilene of West Greenwich, Rhode Island

Answer: It is likely that you are dealing with European apple codling moths (Cydia pomonella) and Asian peach moths (Grapholita molesta). Both exist in Rhode Island, look similar, and cause comparable damage, but one prefers peaches, and the other chooses apples. Here are three suggestions for overcoming these pests in your home orchard.

Know Your Pests

European apple codling moths (Cydia pomonella) are 1 cm, greyish brown, and have curved antennae. Their wings fold into a tent-like shape.

The codling moth is small and mottled with greyish-brown. Its wings fold in a tent-like manner, and it reaches about 1 cm in length. You will see them most often in the orchard from late May to mid-July. (Click here to learn more.) The Asian peach moth is smaller, mottled, gray, and measures about 1/4 inch (5 mm). The wings have mottled light and dark banding and also fold in a tent-like manner.  The first adults of the season appear from mid- to late-May. Subsequent generations appear from June through to mid-July. (Click here for more information.)

Keep Orchards and Trees Clean

In fall, remove all spoiled, fallen fruits that may harbor moths, bag them, and dispose of them away from your orchard. Look for the codling moth’s brownish moth pupae in winter, which can be found in protected spots near where apples are stored and in tree bark. The moths emerge in mid-spring ready to attack fruits.

I also recommend cleaning and disposing of all fallen fruit-tree leaves to reduce the prevalence of any potential fungal diseases that overwinter on dried foliage.

Time Your Spraying

Time your spraying with precision to stop these pests. A good time to first spray trees is in spring a week after they have dropped all of their petals. This should help tackle the first wave of both codling moths and Asian peach moths. The second time to spray is when the fruits are developing. Codling moths lay single white eggs on the fruits and leaves. These can be manually removed from fruits. Never spray trees when they are in flower. Otherwise, you will be killing all the essential pollinators, while not harming the moths.

I recommend two sprays for these pests: Codling moth virus and horticultural oil are approved for organic gardening, and will stop your apple moths, but frequent applications are needed. Organic insecticides with the beneficial bacterium Spinosad work well against both moths, but these sprays can only be applied several times in a season, so read the product instructions.

Use Sticky Traps

There are pheromone traps designed to just trap and kill these two pests. Set them up by mid to late May just before the first round of moths start flying. These should really help lower your populations and save you some fruit.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do You Repair Rotten Holes in Tree Trunks?

How Do You Repair Rotten Holes in Tree Trunks?

“My pear tree has some large rotten holes on the trunk. What can I fill these up with (concrete)?” Question from Craig of Big Bar, California

Answers: That is an excellent question. The key is cleaning up trunk holes to stop the rotting process. Concrete won’t cut it (it’s also a chainsaw hazard), but there are some practices and products that will. Wound healing and closure is the goal. Here are my suggestions for treating your peartree trunk holes in four steps.

  1. Gently scrape away the soft, rotted wood in the holes to reveal the living tissue. Take care not to cut into any protective firm wood or living tissue! I recommend wearing Kevlar gloves to protect against potential cuts and using a planting knife to remove any bulk, loose deadwood, and a wood-shaving tool to scrape away dead wood closer to the living tissue. Clean your tools with a 10% bleach solution, before and after work, to avoid potentially spreading disease.
  2. Once the holes are free of dead tissue you can either leave them to naturally heal, if the damage is just peripheral, or you can treat them with an antifungal spray and effective tree-wound sealer.
  3. If you want the extra protection of a fungicide and sealer*, I recommend first spraying the area with liquid copper fungicide spray. Once it has dried, try using quartz-based Tree Bandage, which is promoted by foresters and is said to be breathable and truly protective.
  4. If you want to fill the hole to keep animals out, I suggest using a high-powered stapler to stable a piece of strong screen over the hole. But, if you like animals this step is unnecessary.
*Do not use petroleum-based wound paints. Studies have shown that tree wound paints containing petroleum, latex paint, shellac, and asphalt do not promote healing and wound closure. (Click here for an article about the myths and concerns regarding wound paints.)

Here are other precautionary measures that can be taken to stop any fungal disease:

  1. Free the root crown of excess soil and mulch (tree volcanos), if needed.
  2. Cutaway any dead or dying branches, being sure to clean tools before and after.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do I Transplant a Japanese Maple Seedling?

How Do I Transplant a Japanese Maple Seedling?

“I recently bought a house in Long Island, NY, and found a 2-foot tall Japanese maple tree (I believe it is a Red Emperor Maple) growing under a much larger tree. The maple apparently sprouted naturally. I would like to transplant it to a more open space. When is the best time to transplant the tree?  See pictures of the tree and proposed a new planting spot. This open location will get much more sun, will that be a problem? Any advice on transplanting (size of root ball; conditioning soil) are welcome. From my reading it seems that it is best to transplant the tree before the first frost in autumn, the root ball should be the diameter of the drip line, and the new soil should be well-draining and mixed with lots of organic matter.” Question from Ron of New York, New York

Answer: The tree looks healthy, and the planting spot looks just fine, but seedling trees like this little Japanese maple (Acer palmatum, USDA Hardiness Zones 5-8) have one flaw relative to nursery stock. Their fine, spreading roots are not as dense as those of potted trees, so they do not transplant as well. There is one way to increase root density for better establishment, root pruning.  If you prune the roots in fall, the tree will be ready to plant before it leafs out in spring. Here’s how.

How to Root Prune a Tree Before Transplant

You will need a sharp flat spade (King of Spades is best), gloves, and probably some pruning shears to cut away the ivy. Trim the ivy away, clear the area to begin digging. Shoot for a root ball with a circumference of 8-10 inches around the tree. Using your sharp spade, make clean, slightly angeled cuts down to the full length of the spade. You may run into competing tree roots from the larger tree. Cut around them as best you can. Once you have made the cuts all around, leave the tree until spring. Where you made the cuts, new feeder roots will grow over the winter to help the tree become well established when you move it in spring, so you don’t need to cut along the drip line.

In spring, pull away the mulch, and dig a hole that is several inches beyond the height and width of your tree’s root ball. Break up some of the backfill to help plant the tree, and reserve the rest to fill in the hole you will create by digging up the tree.

Next, gently dig around your maple along the lines and cuts you made in fall. You will have to dig a bit beyond the cuts to get any roots that you missed towards the bottom. You should see new root growth along the cuts. Wrap the root ball in plastic or burlap to keep it together. If it breaks apart a little, your tree should still make it. From there, I recommend that you click on this link to follow Russell Stafford’s guidelines for planting a new tree.

As to the variety of your Asian-native Japanese maple, it is difficult to say. These maples seed in from planted landscape specimens, and the seedlings are not necessarily true to parent. With that said, it should still be a fine tree. They can reach a maximum height of 25 feet, so it will provide some shade in your front yard.

Happy tree planting!

Jessie Keith

Black Gold Horticulturist

Why Is My Newly Transplanted Tree Wilting?

Why Is My Newly Transplanted Tree Wilting?

“Hi! How do you revive a newly transplanted flowering tree whose leaves and flowers are wilting? It was planted in loose, rich black organic soil (no chemicals have ever been added). It was dug up from my brother’s flower garden, and it was in rocky sandy soil at the time. I brought with me some of the soil it was used to, to add to the hole it was put into. It is being watered every day. It looks worse and worse every day. 🙁 Could you please tell me if it doesn’t perk up yet this year if it will renew itself over the winter and come back next year as it is too beautiful to lose. Thanks for your time and attention in answering my dilemma!” Question from Sylvia of Belle Plaine, Minnesota

Answer: Stop watering! Sometimes too much love–or in this case too much water–can be detrimental to a new planting. If you moved your tree from a location with rocky, sandy soil, and it was growing well there, then it likely requires fast-draining soil and tolerates less water. By moving it to a new location and watering it daily, several things happened. It had too few roots and too much soil moisture while experiencing the shock of transplant.

Tree Transplanting Tips

Wild- or garden-dug trees have sparse root systems with fewer feeder roots, unlike pot-grown trees. When moving them, it is important to retain as much of the rootball as possible to keep the roots intact and undamaged. But, even if you do the best job moving the tree, lots of feeder roots (the fine roots that take up the most nutrients and water) will be lost. Trees are happier when planted in soil with comparable drainage and characteristics to their original native soil–in this case, the soil in your brother’s garden. The addition of light soil amendments, such as Black Gold Canadian Sphagnum Peat Moss, can be helpful, but too much can cause the bathtub effect, so use sparingly. (Click here for good tree and shrub planting/transplanting guidelines.)

After planting, keep the soil around the tree just moist, but never wet. Light moisture will allow new feeder roots to develop, while too much water will overwhelm the delicate, shocked root system of a new transplant and can cause root rot. In your case, I would water the tree weekly in the absence of rain. If temperatures are very high, a little extra water can be added if wilting occurs.

I hope that these tips help and your tree bounces back.

Happy gardening,

Jessie Keith

Black Gold Soils

My Barbados Cherry Flowers are Dropping Prematurely. Help!

“The flower blooms of my Barbados cherry are pink with yellow but they fall off the whole stem while in bloom. What am I doing or I should ask what I am not doing? I water it a little extra, but they seem to keep falling off.” Question from Carol of Joaquin, Texas.

Answer: It sounds like you are hoping for fruits in addition to stopping premature flower drop. It is typical for most of the small pink flowers of Barbados cherry to fall from the tree, but using a product called Blossom Set can help flowers remain for longer to encourage fruiting. It is also important to know that older, more established Barbados cherries flower more because the flowers occur on old wood. Good irrigation and extra care can also help these trees to flower. Try adding compost around the base of the tree and feeding it with a fertilizer formulated for flowering trees and shrubs. (Follow the manufacturer’s recommendations regarding fertilizer quantity and method.)

When it comes to fruiting, planting more than one tree can encourage cross-pollination and fruit set, though some trees are self-fertile. Native bees are the primary pollinators, so avoid using any pesticides on or around your tree.

I hope that this helps answer your question!

Happy gardening,

Jessie Keith

Black Gold Horticulturist