Ceanothus griseus horizontalis
Evergreen, Ground covers, Shrubs
Some species grow in the eastern U.S., Rocky Mountains, the Northwest, and Mexico, but most are native to California. In flower color, they range from white through all shades of blue, from pale powder blue to deep violet-blue. Typically flower in spring. Plants vary greatly in habit: some are low and spreading, others compact and bushy, still others upright and angular. Generally evergreen; a couple listed here lose leaves in cold weather. Only types with small leaves tend to be deer-resistant.
New varieties (most of them propagated from selected wild plants) appear frequently in nurseries, while old ones disappear. For the widest choice, deal with a specialist in Western natives. In Zones 1–3, 8, 9, stay with varieties tested and sold locally.
In the wild, these plants grow on rocky slopes; in the garden, they require excellent drainage. Plant in light, well-drained soil. Some demand total dryness during summer, but others (particularly coastal groundcover types) need occasional summer water if grown away from the fog belt. A few tolerate more frequent summer moisture.
Wait until after blooms have faded to do any pruning, and avoid cutting off any branches more than an inch in diameter. Control plant growth by pinching back shoot tips during the growing season. Ceanothus sometimes get aphids and whiteflies, but these are easy to control.Ceanothus griseus horizontalis
Spreading, slowly mounding growth to 1 1/2–2 1/2 ft. tall and 5–15 ft. wide. Glossy, oval, 2-in., bright green leaves. Light blue 1-in. flower clusters. Sometimes suffers winter damage in Zones 5–7, 14. This is a favorite of browsing deer.‘Diamond Heights’
From 1 ft. high, 6 ft. wide. Green leaves are 1 in., rounded, with greenish-white variegation. Light blue flowers. Less hardy than the species; trouble under 20°F (–6°C). Give afternoon shade inland.‘Yankee Point’
From 2–3 ft. high, 8–10 ft. wide. Glossy, dark green 1 1/2-in. leaves. Medium blue 1-in. clusters of flowers. One of the best ground-covering kinds. Looks refined.
Grows to 12–20 ft. tall, 15–20 ft. wide; can be trained as a small tree. Big (2–3-in...
From 3–6 ft. tall, 5 ft. wide. Glossy, medium green, 2-in. leaves. Dark blue flower clusters; pr...
From 2–5 ft. high, 10–12 ft. wide. Medium green 1-in. leaves. Medium blue, 3–5-in. s...