Blueblossom
Ceanothus thyrsiflorus · Rhamnaceae
📷 Wikimedia Commons · CC BY-SA 3.0
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around blueblossom and prepare for winter.
ID card
- Foliage
- Evergreen
- Flowering
- May to June, bright blue flowers in clusters
- Adult size
- Approximately 2 m tall
- Growth
- Moderate to rapid
- Hardiness
- Moderate, hardy to around -5°C
- Origin
- California (Pacific coast)
- Soil type
- Well-draining, light, tolerates poor soils
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Ceanothus thyrsiflorus tolerates excess water and stifling midsummer heat poorly. Plant it in well-draining soil, south or southwest exposure, and leave it alone—it's a plant for minimal fuss gardening.
The common mistake
Watering regularly or pruning it in winter.
The pro's trick
After a break, wait for visible regrowth before cutting back the damaged wood.
Care
Exposure
Plant your ceanothus in full sun for abundant and generous flowering. It tolerates partial shade but flowers less intensely. This shrub appreciates locations protected from strong winds.
Watering
Water regularly during the first year after planting to encourage root establishment. Once established, ceanothus is drought-tolerant and requires little watering. Let the soil dry between waterings, especially during winter.
Soil and drainage
Choose well-draining, light soil that is slightly acidic to neutral. Ceanothus dreads waterlogging which can cause root rot. Loosen the soil when planting and add gravel if drainage is insufficient.
Pruning and shaping
Prune lightly after flowering (June-July) to maintain a compact, bushy shape. Avoid severe pruning which weakens the plant. Remove dead or damaged branches in spring.
Fertilizer
Fertilizer is generally unnecessary on fertile soil. On poor soil, a balanced fertilizer applied in spring is sufficient. Avoid excess nitrogen which promotes foliage at the expense of flowering.
Diseases and pests
Ceanothus is generally hardy and not very susceptible to pests. Excess moisture promotes fungal diseases; maintain good air circulation. If problems occur, spraying in late winter helps prevent infections.
Did you know?
Ceanothus was revered by California Native Americans who consumed its seeds and used its flowers in decoctions. Its nickname of "New Jersey tea" comes from its historical use as a tea substitute during the American Revolution, when British imports were boycotted.
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
- BuckthornRhamnus alaternus
- JujubeZiziphus jujuba
- Indian jujubeZiziphus mauritiana
- Feltleaf ceanothusCeanothus arboreus
- Point Reyes ceanothusCeanothus gloriosus
Tips generated and checked by Viridia — adapt them to your local climate.