This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Of the many species of flowering shrubs which decorate the hills and valleys of California, few, if any, strike the beholder as more worthy of cultivation than the several Ceanothus. Of this species of shrub, belonging to the natural order Rhamnaceae, we have some nineteen varieties in California. By far the handsomest variety is Ceanothus thyrsiflorus, or the California Lilac, discovered and named by the Russian botanist Eschscholtz. This is a strong grower, forming handsome, well-branched plants, five to eight feet high. The flowers are produced in dense compound racemes about five inches long. The flowers are of a bright ultramarine blue and have a pleasant odor, they are produced in abundance in May and June. Ceanothus cordulatus, well known in California as Snow-bush, is a beautiful companion for the first named variety; the flowers are produced in dense panicles of a pure snow white color. In habit and growth it resembles Ceanothus thyrsiflorus. Ceanothus integerrimus, is a fine variety with racemes of pure white flowers.
It grows from three to five feet high, forming strong well-branched plants; this variety, while not as handsome as the other two, is well worthy of a place in any collection.
Ceanothus Dentatus is a fine variety of a lower growth than the former; the flowers are produced in racemes of a dark blue color, and in such abundance that the plant is literally covered with blossoms, and forms an object when in bloom that the beholder will long remember. Ceanothus diva-ricatus is known as the white flowering California Lilac; the flowers are produced in long racemes, often six inches long, of a pure white color. It grows from five to eight feet high, and forms dense well-branched plants.
Ceanothus Oliganthus is a fine variety, which is unknown except around Santa Barbara. The flowers are produced in racemes about three inches long, in color they are bright blue. Not as free flowering as the other vareities.
Ceanothus Velutinus Or Douglass Ceanothus grows about three feet high; it produces pure white flowers in loose racemes, a very free flowering variety. I am of the opinion that this variety will be hardier than the others in the Eastern States. Ceanothus azureus is a very pretty variety, the flowers produced in racemes two inches long, of a rich blue color.
Ceanothus Spinosus is the highest grower of all the varities, often twenty feet high. The flowers are very fragrant, of a dense deep blue, produced in numerous racemes. Wherever a tall shrub can be used, none will give more satisfaction than this variety of Ceanothus.
The other varieties are equally desirable.