This list of California Lilac's grow in the
chaparral on generally south-facing slopes in rather rocky, well-drained soils.
In their wild conditions Ceanothus plants
have a natural life cycle of 10-15 years, though fire often shortens that span.
There are more than 50 species native to California. The range of
the genus extends from Canada to Central America in Guatamala. There are a few
Rocky Mountain and Eastern US species as well, but most Ceanothus species
live right here in California. Ceanothus can aquire it's own
nitrogen with the help of naturally associated fungi. Judging by the
typical rate of growth and dark leaves Ceanothus does this very
well. Adding fertilizer will just kill off the good fungi and make
room for the bad ones.
Ceanothus plants are better left fending for themselves. Species
range from being treelike with Ceanothus arborescens cultivar like Ray
Hartman to spreading
groundcovers with Ceanothus 'Centennial' and Ceanothus hearstiorum.
A large number of hybrids and cultivars were developed during the drought
in the 1980's but many of those are no longer offered in nurseries.
In the
garden setting Ceanothus are prone to root rot with heavier soils and regular water, but
will usually persist for a decade or more with limited watering. If mulch is piled
around the trunks and branches the moisture is held against the bark and this
causes rot and this will hasten
the demise of the plant. I plant Ceanothus rootballs a little higher than the surrounding
grade. I try to plant on slopes so the surface runoff drains more rapidly.
Drip irrigation helps because the water is placed directly on the ground. I place
the drippers about a foot away from the trunk of a one gallon plant.
Younger plants
definitely have a higher survival rate. I prefer to plant out of one
gallon containers. I often use the lower varieties such as
Ceanothus
hearstiorum in firescapes because the fire requires oxygen and there is not enough for the
fire to rapidly burn through the low matted growth.
