California Lilac: Everything About Ceanothus

A blooming california lilac shrub

California lilacs are characterized by their generous flowering in abundant cascades, especially the evergreen species. They are indispensable in all gardens of temperate climate, where they are the stars of the summer.

In this article, I have gathered for you all the information about this plant, its main characteristics and what you need to know to plant and grow it.

Characteristics of the California lilac

Scientific nameCeanothus supp.
OriginNorth America
FoliageEvergreen or deciduous
Rusticity-5°C to -10°C (-41°F to -50°F)
ExposureSun or mid-shade

California lilacs are small shrubs with deciduous or evergreen foliage. The leaves are small, oval, relatively thin in the deciduous hybrids, more leathery, varnished and ribbed in the evergreen varieties. The flowering is done in small more or less loose ears, pink, purplish or in numerous nuances of blue.

How to grow a California lilac

The california lilac is not very demanding on the nature of the soil, but prefers well-drained soils: heavy soils retaining water favor the rotting of their roots.

After flowering, prune the evergreens moderately to maintain their silhouette, removing one third of the length of the year’s shoots. In February-March, prune deciduous trees by cutting off a third of the main branches and all the branches on the remaining branches 10cm from their start.

Evergreens can be cut back short every 5 to 6 years to re-form the vegetation.

How to grow a California lilac in a pot

The culture in pot is possible, especially for some evergreen species, with the spread out forms to falling forms, but their exuberance is translated only in full ground.

Where to plant a California lilac

The California lilac is a beautiful flowering shrubbery that can be planted in many different locations.

For those looking for a cascading effect, the California lilac can be planted along a slope or hillside, where it will create a stunning visual. It is also a great choice for rock gardens, as its long, arching branches will add a soft touch to the rugged landscape. It can also be planted in a more traditional garden setting, where its fragrant blooms will add a splash of color and delightful scent. Finally, the species with a spreading habit are perfect to decorate staircases.

The California lilac is an ideal choice for any garden, as it is easy to maintain and provides a beautiful display of blooms throughout the spring and summer months.

Our selection

Deciduous California lilacs

Their dimensions are generally 1,20 m in height and 1 m in width. They prefer full sun and don’t like chalky soils.

Plant them in groups of 3 to 5 feet at least, to give the decoration more scope, or in a bed.

The varieties of Ceanothus x delilianus have blue flowers:

  • Gloire de Versailles‘, the most rustic, light blue;
  • Comtesse de Paris‘, indigo blue;
  • Henry Desfossé’, purplish blue.
  • Topaze‘ is distinguished by its smaller dark blue flowers and a smaller size (1 m).

The varieties of Ceanothus x palidus produce pink Fears:

  • Marie Simon‘, bright pink, compact (80 cm);
  • Perle Rose‘, deep pink, more compact bloom and habit.

Evergreen California lilacs

They are less hardy and require a more protected exposure, against a southern wall, for example. They require a soil that is not very calcareous and well drained.

  • C. arboreus ‘Trewithen Blue‘: one of the largest (it can exceed 5 m), pale blue flowers.
  • C. impressus ‘Puget Blue‘: 1,50 to 2 m high, very compact vegetation, dark blue to purplish bloom, very nice glazed leaves.
  • C. impressus ‘Italian Skies‘: 1,50 m height, 2 m diameter, fast growing, dark blue flowers.
  • C. thyrsiflorus ‘Repens‘: 50 to 70 cm high, abundant flowering, light blue.

In a nutshell

It’s easy to take care of, relatively drought tolerant, and provides food for a variety of birds and other wildlife. California Lilac is an excellent choice for any gardener who wants to add a beautiful plant to their garden with minimal work required.

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