How to Grow and Care for Yellowwood Tree

Yellowwood tree, also commonly known as American yellowwood, is a shade tree with a showy floral display in spring and in autumn when the leaves turn yellow-orange. Yellowwood grows somewhat slowly, reaching 9 to 12 feet in about a decade. Its mature size will reach 30 to 50 feet high and equally as wide, forming into a vase shape. When it blooms, intensely fragrant, wisteria-like flowers droop in long terminal panicles of about 10 to 15 inches long and will cover the mature tree in late spring. After the blooms are pollinated, they form brown leguminous pods.

Yellowwood Tree Care

Here are the main care requirements for growing a yellowwood tree:

• Transplant in average garden soil in the late winter and early spring when it's balled and burlapped or transplanted from a container-grown nursery stock at any time during the year.
• Choose a site that offers protection from harsh winds.
• Water regularly for the first year to establish deep roots.
• Prune only in summer.
  

Light

Site this tree in a spot where it will receive at least part sun. Full sun is best to encourage flowering.

Soil

Alkaline and acidic soils are both handled well by this tree as long as soil drains well. It can also tolerate the full range of soils from sand to clay.

Water

For the first year in your garden, ensure the tree gets at least one inch of moisture per week via rainfall or irrigation. Known as a shade tree, the yellowwood works well in urban conditions thanks to its drought tolerance. This tree can handle dry spells as long as the roots have had a proper chance to spread through an initial growing season of regular watering.

Temperature and Humidity

Hardy in Zones 4 through 8, Yellowwood tolerates both hot summers and cold winters well, although intense winter cold can reduce flowering in the spring. It's a low maintenance specimen for your landscape that isn't fussy about humidity.

Fertilizer

The yellowwood is one of the Fabaceae family members that does not utilize nitrogen fixation. You may need to fertilize it if tests show N levels are low and symptoms like yellowing foliage appear. Test to be sure as conditions like drought or overwatering have the potential to also cause yellow leaves.

Types of Yellowwood Tree

The yellowwood belongs to the large Fabaceae (pea) family which includes species like wattles (Acacia spp.), silk tree (Albizia julibrissin), thornless honey locust (Gleditsia triacanthos var. inermis), and the eastern redbud (Cercis canadensis). In addition to the standard white flowered yellowwood tree, try this variety for pink blooms:

Cladrastis kentukea 'Perkin's Pink': produces fragrant pink pea-like flower clusters in early summer; grows 25-40 feet tall

Pruning

You should start pruning when the tree is young to help it keep good branch angles. The branches tend to grow close to each other and the wood can be brittle. Take these steps for adequate pruning:

1. This tree tends to bleed sap from wounds made in the winter, so pruning should be performed in the summer or right after flowering is complete in the late spring.
2. Make sure there is a central leader.
3. Remove crossing branches and weak branch forks.
4. Create strong branch angles that are wide to help keep the tree healthier and make sure new branches are farther apart.
5. Be careful when working on this tree as the bark is thin and can quickly become damaged.

Propagating Yellowwood Tree

Propagate yellowwood trees from hardwood cuttings taken in the late fall or early winter after leaves drop and the tree is dormant. Here's how:

1. Take a 6- to 10-inch cutting that's about the thickness of a pencil from the current season's growth. It should be hard and woody and aim for the spot where the current season stem meets the prior season's stem with a straight cut.
2. Remove any softer. greener growth at the tip with an angled cut.
3. Scrap off a bit of the bark at the straight cut to expose some of the cambium underneath.
4. Dip this end into rooting hormone and insert 1/2 to 2/3 or your cutting into a pot filled with moist potting medium.
5. Keep the potting medium moist. When you see new growth on the cutting, your new plant has developed roots and can be hardened off before allowing to grow outside.

How to Grow Yellowwood From Seed

Follow these steps to grow a yellowwood from seeds:

1. First, scarify the seed to soften the coat by soaking it in warm water for 24 hours.
2. Fill a plastic bag with moist peat moss or vermiculite and place seeds inside.
3. Put the bag in the refrigerator for 60 days, checking the bag periodically to ensure it remains moist.
4. Fill a pot with equal parts perlite, sand, and compost. Moisten thoroughly.
5. Place the seed about 1/4-inch into the soil and cover.
6. Put the pot in bright indirect light and mist the soil occasionally to keep it moist.
7. After germination, continue to care for the seedling until it has developed several sets of leaves.
8. Harden it off and plant it in the landscape.

Common Pests & Diseases

This low-maintenance, highly adaptive native tree does not have many pest or disease issues that crop up. It is possible, however, that verticillium wilt, cankers, rots, and decay could strike. The smooth gray bark may be susceptible to sun scald.

How to Get Yellowwood to Bloom

Bloom Months

Yellowwood tree blooms in late May to early June in its native area.

How Long Does Yellowwood Bloom?

The gorgeous floral display lasts about a week. While the flowers are a key feature of this plant, they can be erratic. Some years, the blossoms will be plentiful; other years, there will be sparse to none. New trees may not bloom for the first 8-10 years.

What Do Yellowwood Flowers Look and Smell Like?

Long panicles of white wisteria-like flowers are about a foot long and cover a tree in a dense, spectacular display. The flowers are sweet, slightly vanilla-scented, and are most fragrant in the evening. They attract bees and Black Swallowtail butterflies.