Ceanothus delilianus
Ceanothus delilianus · Rhamnaceae
The gardener's calendar
Ceanothus delilianus is in full bloom: enjoy it, watch watering in hot weather and let spent flowers feed pollinators before pruning.
ID card
- Scientific name
- Ceanothus delilianus
- Family
- Rhamnaceae
- Form
- Shrub
- Foliage
- Deciduous to semi-persistent
- Flowering
- May to September, blue to blue-violet flowers
- Adult size
- Approximately 1.5 m tall and wide
- Hardiness
- Moderate, prefers mild climates
- Origin
- Horticultural hybrid (American cross)
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Ceanothus hates wet winters: ensure impeccable drainage, even a slight slope. An aerated, poor soil is better than rich soil that holds water.
The common mistake
Growing it in a basin area or compact soil: it will invariably rot in winter, even at -8°C, because the waterlogged root system freezes then rots.
The pro's trick
Plant on a mound or slope if your soil is clay.
Care
Sunlight
Delile's ceanothus demands a very sunny location to flower abundantly. Place it in full sun, ideally against a south- or west-facing wall. Less bright exposure will slow growth and reduce flowering.
Watering
Water regularly during the first year after planting. Once established, this shrub tolerates drought well thanks to its deep root system. Reduce watering in winter. In containers, water more frequently but avoid waterlogging the soil.
Soil and drainage
Ceanothus prefers well-draining, light, rather poor to average soil. Heavy or chalky soils cause chlorosis problems. Amend with sand or gravel if your soil is compact. Optimal drainage is essential to prevent root rot.
Pruning and maintenance
Prune lightly after flowering to maintain a harmonious, compact shape. Avoid severe pruning which weakens the plant. Remove dead or diseased wood as soon as you notice it. Light spring pruning rejuvenates the shrub.
Fertilizing
Ceanothus is not very demanding. A low-nitrogen fertilizer application (rich in potassium and phosphorus) in spring is sufficient. Avoid overly rich fertilizers which promote foliage at the expense of flowering. Well-decomposed compost as annual mulch is beneficial.
Diseases and pests
This shrub is generally robust. Watch for scale insects or whiteflies in hot, dry climates. Chlorosis may occur on overly chalky soils. Ensure good drainage to prevent fungal diseases. Good air circulation limits health problems.
Did you know?
Delile's ceanothus is a hybrid created in France in the 19th century, resulting from a cross between Ceanothus americanus and other North American species. This shrub remarkably resists poor soils thanks to its ability to fix atmospheric nitrogen through symbioses with nodal bacteria. Its name 'Delile' honors a 19th-century French botanist who contributed to enriching European ornamental flora.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- Alder buckthornFrangula alnus
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- Indian jujubeZiziphus mauritiana
- BlueblossomCeanothus thyrsiflorus
- Feltleaf ceanothusCeanothus arboreus
Tips generated and checked by Viridia — adapt them to your local climate.