Flame Thrower is a redbud bred for its leaves, which come out burgundy and shift through red, orange, yellow and green all season, with several colors showing on the same branches at once.1Monrovia. Flame Thrower Redbud Underneath the show it is a cultivar of the native eastern redbud, so it needs much the same easy care as the wild tree. The one twist is that the conditions that suit the tree and the conditions that show off its color are not quite the same, so where you plant it matters more than with a plain redbud.
Where Flame Thrower Redbud Grows Best
Flame Thrower is rated for USDA hardiness zones 5 through 9, which covers most of the eastern and central US.2North Carolina Extension Gardener Plant Toolbox. Cercis canadensis Flame Thrower A hardiness zone is a band on the USDA map set by how cold winters get, so zone 5 means winter lows down to about -20°F. The tree also needs a winter chill before its flowers set properly, so in the warmest southern spots it may bloom less.3Gardenia. Cercis canadensis Flame Thrower (Eastern Redbud)
It grows in full sun to part shade.4NC State Extension Gardener Plant Toolbox. Cercis canadensis Flame Thrower® ‘NC2016-2’ It produces the most flowers in full sun, while part shade is the better choice where summers are hot.5Gardenia. Cercis canadensis Flame Thrower (Eastern Redbud) In zones 5 to 6, full sun gives the most flowers and holds up well. In zones 8 to 9, a spot with morning sun and afternoon shade reduces heat stress. Bright light under tall trees usually counts as part shade, but deep, all-day shade will thin both the flowers and the leaf color.
To judge a candidate spot, note where the shade falls at 3 p.m. in July, since afternoon shade matters most in the hottest regions. The east side of a house or a spot beside taller trees often gives morning sun and afternoon relief without costing many flowers. In cooler northern yards you can skip the afternoon shade, and a bright open spot shows the color best.
The tree tolerates a wide range of soil pH and does well in moist, well-drained soil of average fertility.6NC State Extension Gardener Plant Toolbox. Cercis canadensis Flame Thrower® ‘NC2016-2’ It performs best with regular, consistent moisture,7Gardenia. Cercis canadensis Flame Thrower (Eastern Redbud) but avoid low spots where water pools after rain. To check drainage before planting, dig a hole about a foot deep and fill it with water. If the water is still standing after a day, drainage is poor, so pick another spot or plant on a gentle mound instead.
Expect it to reach about 15 to 20 feet tall and around 10 feet wide.8GardenLady.com. I Love Flame Thrower® Redbud aka Cercis canadensis ‘NC2016-2’ Give it a spot at least 5 to 6 feet from walls and paths so the canopy can spread.
Planting and Watering
Plant in spring or fall, when cooler weather lets the roots grow before summer heat. Dig a hole two to three times as wide as the root ball but no deeper, so the top of the root ball sits level with the ground. Fill the hole with the native soil, water it in, and spread 2 to 3 inches of mulch, leaving a gap around the trunk.
A few mistakes cause most early trouble. Burying the trunk flare invites rot, so keep the flare above the soil. Mulch piled against the bark like a volcano holds moisture on the trunk. Heavy amendments in the hole can keep roots from spreading into the surrounding soil. And if the tree is pot-bound, tease or cut circling roots before planting.
A newly planted tree needs deep watering through its first season or two. Deep, less frequent watering pushes roots downward, while light daily sprinkles keep them shallow and leave the tree more vulnerable to dry spells. Push a finger about 2 inches into the soil near the root ball and water only when it feels dry. Let a hose trickle slowly at the base so the water soaks in rather than running off. In dry weather, that means once or twice a week through the first season. Ease off once the leaves drop and the tree goes dormant in winter.
Once established, the tree is tougher than that routine suggests. In a three-year trial in a dry climate, field-grown redbuds kept adequate growth and appearance even when given about a third of full irrigation.9Journal of Environmental Horticulture. Influence of Irrigation Regime on Water Relations, Gas Exchange, and Growth of Two Field-grown Redbud Varieties in a Semiarid Climate Redbuds from drier regions have smaller, thicker leaves and inherited traits that help them cope with drought.10Forest Science. Genetic Variation in Leaf Morphology and Plant and Tissue Water Relations During Drought in Cercis canadensis L Once established, the tree tolerates dry spells, though steady moisture keeps it looking best.
Keeping the Leaf Color Bright
Flame Thrower is a cross between ‘The Rising Sun’, a gold-leaf redbud, and a purple-leaf weeping redbud bred at NC State.11NC State Extension. Cercis canadensis Flame Thrower New leaves emerge burgundy, fade to yellow, then mature to green.12Monrovia. Flame Thrower Redbud Before the leaves appear, pink to light purple pea-shaped flowers cover the stems in April.13NC State Extension Plants. Cercis canadensis Flame Thrower Color variety peaks from early to mid-season and fades as summer heat rises after mid-July. A greener tree in August is normal and is not a sign of sickness.14NC State Extension Gardener Plant Toolbox. Cercis canadensis Flame Thrower® ‘NC2016-2’
Good light encourages the steady flush of new burgundy growth that gives the tree its show, so deep shade dulls it. Drought stress in early summer can scorch the delicate yellow leaves, so water during dry spells then. Heavy fertilizer pushes plain green growth at the expense of the colorful leaves. Yellowing combined with wilting or dieback on one branch is different from the normal yellow of new growth and may point to disease, covered below.
Fertilizing a Redbud
Redbuds belong to the bean family.15NC State Extension. Cercis canadensis Flame Thrower Unlike most bean-family plants, though, eastern redbud cannot pull nitrogen from the air, because it lacks the root nodules and bacteria that do this.16Penn State Extension. Eastern Redbud: A Superb Tree for Almost Any Landscape Poor soil may need some nitrogen, but average soil suits it well.17NC State Extension Gardener Plant Toolbox. Cercis canadensis Flame Thrower® ‘NC2016-2’ Feed only if growth is weak, using a light, slow-release product in spring.
Very short new shoots year after year suggest low fertility, but a single dry year can also stunt growth. Pale leaves across the whole tree, not just the normal yellow stage on new growth, can signal hunger. A soil test before feeding avoids guessing and shows what, if anything, is missing. Mulch breaking down adds nutrients slowly, which is often enough on its own.
When and How to Prune
Make shaping cuts after flowering ends but before the leaves are fully out, and no later than mid-April.18Gardening Know How. Cutting Back Redbuds: How And When To Prune A Redbud Tree Redbud forms next year’s flower buds on this year’s wood during summer,19Atlanta Arbor. How to Grow and Care for a Flamethrower Redbud so shaping cuts made in summer or fall remove next spring’s flowers. You can cut out dead, damaged or diseased wood in summer, though.20Atlanta Arbor. How to Grow and Care for a Flamethrower Redbud
On a young tree, choose one or a few main trunks and remove competing leaders early, since a clear structure now prevents big cuts later. Remove branches that cross and rub, because rubbing wounds invite disease. Cut just outside the branch collar, the slightly swollen ring at the base of the branch, rather than flush with the trunk. Take no more than about a quarter of the canopy in one year so the tree is not stressed.
When removing diseased branches, cut well below any sunken or discolored area. Wipe your pruners with alcohol between cuts, and bag the diseased wood instead of composting it.
Diseases to Watch For
The most serious redbud disease is a canker, a fungal infection that creates sunken dead patches on stems and twigs.21U.S. Department of Agriculture, Forest Service. Cercis canadensis L. Eastern Redbud It can kill branches, and whole groves of redbuds have died from it.22U.S. Department of Agriculture, Forest Service. Cercis canadensis L. Eastern Redbud Prune out cankered stems promptly, cutting into healthy wood.
Verticillium wilt is a disease caused by a soil fungus that clogs the tree’s water-carrying tissue and sometimes kills redbuds, especially in the Midwest.23U.S. Department of Agriculture, Forest Service. Cercis canadensis L. Eastern Redbud Every redbud species tested has been susceptible.24Pacific Northwest Pest Management Handbooks. Redbud (Cercis spp.)-Verticillium Wilt Do not replant a redbud where one has died of wilt.
Wilt shows as leaves suddenly wilting or browning on one side of the tree or on one branch, and wilted wood may show dark streaks under the bark when cut or peeled. A local extension office can confirm which disease it is.
Leaf anthracnose, a fungal leaf spot, is another common redbud disease.25U.S. Department of Agriculture, Forest Service. Cercis canadensis L. Eastern Redbud It mainly spoils how the leaves look, and raking up fallen leaves helps reduce it. Drought and wounds make trees more vulnerable, so keep mowers and string trimmers away from the trunk.
Insect Pests
Redbud pests include aphids, Japanese beetles, treehoppers, leafhoppers, caterpillars, borers, webworms and scale.26ask.extension.org. Red Bud leaf problem–white, web-like blothches Sap-sucking insects leave tiny pale spots on the leaves.27ask.extension.org. Red Bud leaf problem–white, web-like blothches Check the undersides of the leaves, where leafhoppers, treehoppers and aphids feed.28ask.extension.org. Red Bud leaf problem–white, web-like blothches
Some caterpillars on the tree are native butterflies or moths, so tolerate light feeding. A strong spray from the hose knocks off aphids with no chemicals. Use insecticidal soap only for heavy infestations, since even gentle products can harm beneficial insects. Borers mostly attack stressed trees, so borer holes in the trunk are a sign the tree needs better care.
Companion Plants and Garden Placement
Its bright colors pair well with the solid deep greens of hostas, boxwood, grasses and ferns.29New Blooms Nursery. Flame Thrower® Redbud It is larger than ‘The Rising Sun’, so it works best as a single specimen tree.30New Blooms Nursery. Flame Thrower® Redbud Native perennials suit it if you want a native garden.31New Blooms Nursery. Flame Thrower® Redbud
In shadier beds, choose hostas and ferns, which tolerate the lower light. In sunnier beds, choose grasses and boxwood. Dark mulch sets off the warm leaf colors.
What It Does for Wildlife
Bees visit the early spring flowers for nectar and pollen.32NC State Extension Plants. Cercis canadensis Flame Thrower Twelve species of butterflies and moths use it as a caterpillar food plant, including Henry’s elfin butterfly.33NC State Extension Plants. Cercis canadensis Flame Thrower Birds eat the seeds.34NC State Extension Plants. Cercis canadensis Flame Thrower Skip broad-spectrum sprays in spring, when bees and caterpillars are using the tree, and leave the seed pods on for birds.