mountain lilac tree

Ceanothus West coast home of the best blues.
While most Wild Lilacs with the deepest blue flowers are derivatives of California species Oregon has several of its own. Ceanothus thyrsiflorus- the species from which ‘Skylark’, ‘Victoria’, and ‘Oregon Mist’ were selected is native to a very large area of SW Oregon. As far north as Lane County “BlueBlossom” adorns hillsides and bluffs with powder blue flowers in April and May. We continue to make selections from the far northern range of this and other species to ensure more hardiness to cold. There are several important things to know about Ceanothus before you make them part of your garden. First, is that they are successional plants in the wild. Often they are the first woody shrubs to occupy areas following disturbance such as fire. All are nitrogen fixers and aside from improving the soil some species actually provide shading for trees such as Alder and Douglas Fir which will eventually overtop and shade them. Contrary to popular belief they tolerate many types of soil so long as they are all well drained to dry in summer. Over-improved soil will lead to prodigious growth, less hardiness to cold, and can leave the larger varieties susceptible to wind-rock. Tip pruning Ceanothus yearly (after blooming has ended) will often ensure a more compact, wind-fast plant and create more growth which supplies blooms. As a group expect them to live as little as 7 years and as much as 20 if they are strictly unwatered. There are two distinct types of Ceanothus found in the wild-those with holly-like leaves have been casually designated as Cerastes-types in the past. C. gloriosus, is an example of this designation. The other type is known as, well, Ceanothus ssp. Ceanothus

Xera Plants introduction 2004
Ceanothus thyrsiflorus ‘Oregon Mist’ Zn7a (0º to 5ºF) Rhamnaceae
Very odd that a genus cherished in California and Europe- with many native representatives in Oregon has NO selections made from this state. We’ve decided to change that by selecting a form of Blueblossom from near its northern native limit. From Coos County we chose this variety for its deep green leaves and striking turquoise blue flowers. Large growing evergreen shrub that should provide superior cold hardiness. Also, it is a great representative of this species in the wild. We took cuttings of this plant where it grew simultaneously with a salmon flowered variety of Rhododendron occidentalis inbetween California Bay (Umbelluaria) and blue flowered Iris douglasiana. Interesting that this shrub grew in heavy clay soil where running water flows during winter. To 8’ tall and as wide very quickly. May grow larger in optimum conditions, tip prune to limit size, increase density and blooming wood. Flowers late April to late May. Excellent shrub for low water native gardens. Underplant with Pacific Coast Iris which bloom concurrently and have the same cultural requirements. May also be used as a small garden tree.
PNW NATIVE

Ceanothus thyrsiflorus ‘Skylark’ Zn7a (0º to 5ºF) Rhamnaceae
'Skylark' is a selected form of Ceanothus thyrsiflorus which is native from Oregon south. To 6' tall x 6 'wide with sky-blue, sweetly scented flowers in an initial large flush in late spring and then lightly for the rest of the year! Takes light irrigation but is very drought tolerant. Smaller with less water. Full sun to light shade. Tip prune to shape after flowering. Cold hardy. Evergreen. Smaller than C. 'Victoria'. Very easy to grow.

Ceanothus thyrsiflorus ‘Repens’ Zn7a (0º to 5ºF) Rhamnaceae
A low spreading selection of one of Oregon's native Ceanothus. Very fast growing to 1' tall by 8' wide. Large clusters of powdery-blue flowers appear in April and May. Give full sun and water until established, thereafter it is very drought tolerant. Excellent large bank cover. Very showy in spring and combines well with Cistus and Halimium. Much less tender to cold than other creeping varietes.

Ceanothus x thyrsiflorus ‘Tilden Park’ Zn7b (0º to 5ºF) Rhamnaceae
Our continuous search for small Ceanothus brings us to this proported hybrid
between Ceanothus thyrsiflorus and an unknown suitor found in Tilden Park.
Vivid blue flowers appear in late April and May on a vigorous shrub to 4’ tall and
6’ wide in five years. Leaves are deep green and considerably smaller than other Ceanothus thyrsiflorus. Clean looking shrub. Avoid soil amendments and water only until establishment in its first season.

Ceanothus x ‘Topaz’ Zn7b (5º to 10ºF) Rhamnaceae
A compact semi-deciduous Ceanothus that blooms in the summer with perhaps some of the darkest flowers of the genus. Deep blue/black flowers appear from late May to frost followed by red seedheads. To only 4' tall and as wide. Full sun and well drained soil. Occasional summer water. Prune after flowering. Blooms on new wood. Protected locaton- takes blasting summer heat well. Favorite food source for butterflies.