Articles

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 Seed-Grown Plants Attract Honeybees?

“I would like information on ordering flower seeds that would attract honey bees to my garden.” Question from Randy of Bastrop, Texas

Answer: There are loads of garden flowers that are easily grown from seed and especially attractive to bees. Considering your location, your bee plants should also be heat and drought tolerant. Here are a few easy-from-seed plants that will grow well in Bastrop. (There are many great catalogs for flower seeds. Select Seeds is a great option.)

Each year I grow my favorite flowers indoors from seed in Black Gold Seedling Mix under fluorescent grow lights, but a few of those on this list can be directly sown outdoors. (For a full seed-starting tutorial, click here!) Some of the easiest bee flowers for you include:

Purple Cosmos (Cosmos bipinnatus)

The colorful, delicate pink, rosy-purple, or white daisies of cosmos attract bees and butterflies. They also sprout and grow quickly.

Seed Starting: Lightly cover seeds with seed starter, keep them slightly moist until they sprout. These can also be started outdoors in spring after frosts have past. Work up your garden bed, sprinkle seeds across the weed-free ground, and then lightly cover the seeds with peat moss and gently water them in. Keep them lightly moist and expect sprouting within a week or two.

Purple Coneflower (Echinacea purpurea)

These tough, native perennials flower in the first year from seed and last for years in the garden. Their large, purplish-pink flowers bloom through summer, attracting bees and butterflies. If fall, goldfinches and other songbirds eat their seeds.

Seed Starting: Lightly cover seeds with seed starter, keep them slightly moist, and maintain a temperature of 68º F. Germination should occur within three to four weeks, sometimes earlier.

Blanket Flower (Gaillardia x grandiflora)

Few summer bloomers can top the resilience, beauty, and ever-blooming nature of this tough, North American native, which is also a Texas native. It blooms in the first year from seed, and bees love it.

Seed Starting: Lightly cover seeds with seed starter, keep lightly moist and maintain a temperature of 68º F. Germination should occur within one to two weeks, sometimes a bit longer.

Sunflowers (Helianthus annuus)

Everyone loves sunflowers, and so do bees. Watch the video below to learn how to grow them.

Marigolds (Tagetes spp.)

Whether you prefer tall African marigolds or short French marigolds (Tagetes hybrids), these heat-loving annuals for bees sprout from seed in a snap. Start them as you would purple cosmos.

Zinnias (Zinnia elegans)

Zinnias come in low-growing forms fit for sunny border edges or containers. Tall forms are better for cutting gardens or large flower beds. Start them as you would purple cosmos.

Happy bee gardening!

Jessie Keith

Black Gold Horticulturist