Sonoma plants (Ceanothus sonomensis) are rare shrubs found only in California, most of which are found in Sonoma County, according to the Sonoma County Master Gardener's website. The sonoma plant is a species of buckthorn, which is a large group of flowering shrubs native to North America. The shrub is distinctive, with dark green, fuzzy leaves edged with teeth and clusters of purplish-blue flowers. Care of the sonoma plant is similar to many other plants native to the state.
The sonoma shrub is found growing along the foothills of Sonoma valley. This plant thrives in locations that receive full sunlight and will not grow or bloom well if planted in a shady location. Choose a location that receives a full day's worth of sunlight, at least six and preferably more hours of sunlight per day.
Ceanothus sonomensis grows well in poor soil, such as rocky or sandy soil. They are often found in soils with poor nutrient content, low fertility soils, according to information published by Sonoma County Master Gardeners. Therefore, you do not have to amend your soil with rich organic matter before planting these shrubs. Do make sure that the soil is well-draining, as sonoma plants will not tolerate soggy or waterlogged soil, such as areas of ground that collect standing water.
Sonoma plants are drought tolerant. They require little in the way of water and can survive long periods of hot, dry weather. You do not have to water your shrub often. One or two times per month is enough for most sonoma plants in home gardens. For established plants, water when the soil dries out to the roots. Deep waterings are best, according to the Sonoma County Master Gardeners. Use a drip hose to water the plant slowly and deeply over a period of several hours.
Prune sparingly. This plant puts out shoots on new wood only, so do not aggressively hack away at this plant. Instead, remove broken or dead branches from the interior of the plant and perhaps a few at the bottom to shape it. Prune in early spring before blooms appear.
Deer tend to enjoy this plant. If you have a problem with deer, you may want to place it in a location where deer cannot access it, such as inside a fence, or surround it with deer-resistant plants, such as Anise hyssop or wormwood. Water left sitting on the leaves, such as with overhead irrigation, can lead to the development of leaf spot, a fungal disease. Always water at soil level.