Blue Mountain Lilac Ceanothus thyrsiflorus

Blue blossom is an easy to grow broad leaf evergreen shrub in the buckthorn (Rhamnaceae) family that, left to its own devices, will grow to a large, tree-like 20 feet high and wide. However, it has a short trunk and spreading branches that can be controlled to spread to a few feet tall.  In natural settings, it is ofen found on wooded slopes and canyons, in the neighbourhood of streams, and in evergreen forests of California and Oregon. Blue blossom has truly blue flowers which all gardeners know can be incredibly difficult to find. It can be used for screen and background plantings in large spaces and on slopes.

This shrub is very low maintenance and can be used for a ground cover and for erosion control. The evergreen leaves stay put and the blue flowers fall off individually and are easily blown away by the slightest wind. The densly packed foliage provides excellent cover for songbirds. The genus name comes from keanothos, an ancient Greek name relating to some plants in the buckthorn family. The specific epithet thyrsiflorus means "flowers arranged in a thyrse", in reference to the shape of the infloresence ( thyrsus is the name of the staff, adorned with leaves and berries, that belonged to Bacchus, the Greek god of wine).

Blue blossom is a hardy plant, but it dislikes root disturbance and it should be planted in its permanent site. It is a fast-growing plant that flowers when young. It dislikes heavy pruning and it is best not to cut out any wood thicker than a pencil. Keep in mind when pruning that the plant flowers on the previous year's growth and any pruning is best done immediately after flowering. Constant pruning to keep Blue blossom small can shorten its life.

Diseases, Insect Pests, and Other Plant Problems:

No known diseases or insect pests. May freeze with colder winters. Elk and deer will browse the foliage.