shrub RHS Award

Dark Star California Lilac

Ceanothus x impressus 'Dark Star'

The Story

Plant Bio

Ceanothus x impressus 'Dark Star' is a hybrid California lilac known for its striking blue flowers and dense, evergreen foliage.

This cultivar is particularly admired for its dark blue flower clusters and robust growth, making it an excellent choice for low-maintenance gardens.

Uses & Benefits:

Provides striking dark foliage and vibrant blue flowers, enhancing garden aesthetics.

Drought-tolerant and low-maintenance, ideal for water-wise landscapes.

Supports pollinators like bees and butterflies, contributing to local biodiversity.

Essentials

At a Glance

Plant Type

Shrub

Height

72 inches

Width

108 inches

Light

Full Sun, Partial Sun

Zones

7, 8, 9, 10

Water

Low

Humidity

Low to Average

Lifespan

10-20 years

Native To

California (hybrid)

Toxicity

Non-toxic

Bloom period

Spring – Late summer

In flower about 5 months of the year

Planting

How to Grow

Tuck well-draining soil into planting site for optimal growth.
Mist cuttings regularly to maintain humidity and encourage rooting.
Plant in full sun for best flowering and foliage development.
Water deeply but infrequently to promote drought tolerance.
Fertilize in early spring with a low-phosphorus fertilizer.
Prune lightly after flowering to maintain shape and health.

Pro Tip

Use well-draining soil and avoid overwatering to prevent root rot.

Keep It Thriving

Care Guide

Do

Provide full sun for vibrant blooms and healthy foliage 🌞
Water deeply during dry periods to support drought tolerance 💧
Prune after flowering to shape the plant and remove dead branches ✂️
Feed with a balanced fertilizer in spring for vigorous growth 🌱

Don't

Avoid overwatering which can lead to root rot ❌
Do not prune in late fall or winter to prevent stress ❌
Refrain from fertilizing with high phosphorus fertilizers 🌱❌
Never plant in heavy clay soil without amendments ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Mulch
Plant
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Arid-themed garden borderSilver-foliaged shrub for xeriscapingVanilla-scented hedge

Companion Plants

Lavender SalviaRussian sage Sedum Agave

Multiply

Propagation Methods

Good to Know

Common Questions

Dark Star California Lilac questions

What zones can Dark Star California Lilac grow in?

Dark Star California Lilac is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Dark Star California Lilac deer resistant?

Yes — Dark Star California Lilac is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Dark Star California Lilac bloom?

Dark Star California Lilac typically blooms in spring through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Dark Star California Lilac need full sun?

Dark Star California Lilac does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Dark Star California Lilac drought tolerant?

Yes — once established (usually after the first full season), Dark Star California Lilac handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.