Caring for a Preston Lilac (Syringa x prestoniae)

Successfully growing a Preston Lilac requires thoughtful consideration of your local climate and soil conditions. This guide is based on firsthand experience from the Nikka Yuko Japanese Garden in Lethbridge, Alberta—a city located in hardiness zone 4B, where winters are cold, and the climate is relatively dry. You can also see Preston Lilac by visiting Nikka Yuko.

Planting Location:

Full Sun: Preston Lilacs thrive in full sun, so choose a location that gets at least 6 hours of direct sunlight each day.

Quick Growing Guide

Botanical Name: Syringa x prestoniae

Colour:

• Pink

Blooms:

• Spring
• Summer

Sun / Shade:

• Full Sun

Watering:

• Sparingly

Soil:

• Slightly Alkaline
• Well drained

Height:

• Up to 9+ feet (over 3 meters)

Width:

• Up to 10 feet (300cms)

Hardiness Zones:

• 2
• 3
• 4
• 5
• 6
• 7

Care:

• Moderate

Well-Drained Soil: Ensure the soil is well-draining as lilacs don’t like wet feet. If your soil tends to be heavy or clay-like, amend it with compost or sand to improve drainage.

Wind Protection: Lethbridge can have strong winds, so planting your lilac near a windbreak (like a fence or building) can help protect it from wind stress.

Soil and Fertilization:

Soil pH: Lilacs prefer slightly alkaline to neutral soil (pH of 6.5 to 7.0). If your soil is too acidic, you can add lime to raise the pH.

Fertilizing: You can fertilize your lilac in early spring with a balanced fertilizer (10-10-10) before new growth starts. Avoid over-fertilizing, as too much nitrogen can reduce flowering.

Watering:

Moderate Watering: Water the lilac deeply but infrequently. During dry periods, water every 7-10 days, but make sure the soil drains well so the roots don’t sit in water.

Mulching: Apply a layer of mulch (2-3 inches) around the base of the plant to help retain moisture, suppress weeds, and protect the roots in the winter.

Pruning:

After Blooming: Prune your Preston Lilac after it has finished flowering, typically in late spring or early summer. This encourages healthy growth and prevents cutting off next year’s flower buds.

Deadheading: Remove spent flowers to keep the plant looking neat, and trim back any dead or damaged wood.

Winter Care:

Protection Against Cold: Lethbridge has cold winters, so consider wrapping the base of the plant with burlap or using mulch around the roots to protect them from extreme cold.

Snow Cover: Snow can act as insulation, so let nature protect your lilac if you have snowfall. If it’s a particularly harsh winter, consider adding extra mulch.

Avoid Pruning in Fall: Don’t prune in late fall because it could stimulate new growth that won’t harden off before the winter freeze.

Pest and Disease Control:

Monitor for Pests: While lilacs are generally resistant to pests, they can occasionally attract aphids or powdery mildew. Treat with insecticidal soap or remove affected leaves as necessary.

Air Circulation: Ensure good air circulation around the plant to reduce the risk of fungal diseases like powdery mildew, especially in the humid summer months.

Winterizing and Mulching:

Each fall, applying a 3-4 inch layer of mulch around the root zone to help protect against temperature fluctuations.

Since the Preston Lilac is quite hardy, it should withstand Lethbridge’s cold winters as long as it is well-established and has good soil drainage.

With proper care, your Preston Lilac will bring vibrant color and fragrance to your landscape for years to come.!

More Resources

For more insights on lilac propagation and pruning.