Growing Tree-Form Wisteria (Standard Wisteria): Elegant Small Tree for the Garden

Overview

The spectacular beauty and vigor of wisteria (pronounced wis-teer'-ee-uh) are best showcased by training it as a small tree, or standard. Long racemes of fragrant May flowers drape from a compact head of foliage shaped by pruning, creating a graceful, stately specimen perfect for mixed borders.

Choosing a Site

Wisterias flower best and grow most vigorously with at least 6 hours of direct sun daily. They thrive in any well-drained soil.

Planting

1. Soak bareroot roots in water for a few hours.
2. Dig a hole wide enough for the root spread and deep enough to set the crown 1 inch below soil surface.
3. Arrange roots like spokes of a wheel, taking care not to break brittle roots.
4. Backfill, firm soil, and create a soil rim to form a watering basin.
5. Water thoroughly.

Note: Keep roots covered until planting to prevent drying out.

Staking

Tree wisterias need strong support. Drive the provided wooden stake 6–12 inches deep, ½ inch from the trunk. Secure trunk to stake at several points 8 inches apart with plastic tie tape. Replace with a larger stake or steel pipe as the trunk expands. Check ties in spring and fall to ensure they are not too tight. Plants should always remain securely staked.

Watering and Fertilizing

• First year: Provide 1 inch of water per week (water deeply once a week if rainfall is insufficient).
• Established plants: Water only during prolonged dry spells.
• Fertilizer: Little to none needed; excess inhibits bloom. If soil is very poor or sandy, apply a light feeding of 5-10-10 or 5-10-5 at ¾ cup per square yard in early spring.

Overwintering

• Cold climates (Zone 5 and colder): Protect the main stem for the first few winters with a slit piece of plastic tubing. On older specimens, tie branches together with twine in a cat's-cradle fashion to prevent wind and ice damage.

Pruning

• Light, frequent pruning: Trim long twining branches produced in summer to preserve the globe shape.
• Hard pruning (late summer/early fall): Cut current season's growth back to 5–6 large buds (leaving 6-inch stubs) and remove poorly placed branches entirely. This controls growth and encourages flower bud formation.

Wisterias are very forgiving; vigorous growth the next season gives a second chance for any pruning mistakes.