There’s nothing like the smell of sweet violets in late winter and early spring. But the regular species in our climate is nothing less than a thug. It seeds and grows where you really would rather not have it. Well, forget that. Enter this exquisite fully double flowering Parma Violet. The rich violet blue flowers appear on long stems from January to April. Parma violets are the Mediterranean form of V. odorata and they are less hardy to cold and not so rampant. This form we have never seen set seed- but there are always exceptions. Very glossy green foliage frames the flowers well. Excellent in containers in an unheated greenhouse, conservatory. In the garden choose a protected spot (under evergreen shrubs for example) and give this violet rich soil with regular summer moisture. Tolerates full sun but looks better with some shade. Flowers tend to lean horizontally, they are great for cutting and making little fragrant winter posies. Spreads by runners to form a nice patch in time. Tolerates summer drought when established.
Biome: Low Water/No Water
Rainfall in the Pacific Northwest takes an annual break during our summers when days are longest and hottest and evaporation far exceeds anything that falls from the sky. It makes sense to seek out plants that are adapted to dry summer conditions. A large selection of these plants are from the Mediterranean or are natives of the West Coast. Most importantly, these plants save water and money without sacrificing good looks. And many drought adapted plants actually shun summer water. Its wise to group these plants together and designate a no water zone. You’ll be amazed at what a beautiful vibrant garden you can have without irrigation. Find the right plants and then trust their built in adaptation- its a simple and smart way to garden. And it saves resources- as well as the gardeners precious time. The following plants once established will weather a hotter than normal summer without undue stress. That is one or more years after installation. The better you treat a plant in the beginning the sooner it will develop drought adaptation. The better established the more drought tolerant.
Climate Adapted Plants for Gardeners in the PNW
Viola praemorsa ssp. praemorsa
Canary violet or upland Violet has many subspecies in the PNW and west in general. This is our own Willamette Valley form of this intriguing handsome perennial. Large spoon shaped leaves have an underside with conspicuous hairs. The top of the leaf is glossier. In April-May bright yellow flowers appear. The bottom petal has conspicuous black whiskers. In our region this violet is local in the most undisturbed sites but it shows very good persistence in competition with non-native introduced grasses. My experience is that it favors rocky and scree sites that remain somewhat cool- for instance the north side of a steep slope. To 6″ tall and forming expanding plants. Winter deciduous. Arrives early in spring and can go summer dormant with high heat. Excellent planted in fall or winter and left to its own devices. Average to enriched soil yields the best results. This is one of the showiest violets native to the Willamette Valley. Fairly long lived. Little deer resistance. Some associated plants are Olysinium douglasii, Sedum spathulifolium, Dodecatheon hendersonii. Oregon native plant.
Vitex agnus-castus ‘Sensational’
Excellent California selection of Chaste tree with thicker, bluer flowers. Large growing shrub with aromatic finely divided leaves in mid-July in PDX spires of blue flowers erupt from each branch tip. It remains in bloom for 3-4 weeks. And if you remove spent flowers more will appear. Full sun and poor to average well drained soil. No summer water when established. Attains tree-like status with great age. May be pruned back hard in spring to contain the ultimate size. Blooms on new wood. Long lived and hardy below 0ºF. Leaves appear late in spring- often not until mid-May. Be patient. Loved by pollinators and bumble bees specifically. A shrub in full bloom will be a haze of drunken bumbles who after a day of working will often fall asleep in the flowers of this shrub. Tolerates the hottest sites and is very long lived.
Watsonia latifolia
A true red flowered Watsonia and one of the hardiest of the genus. Wide green spikey leaves rise to 2′ tall in spring. In late spring to early summer 3′ tall spikes of tubular true red flowers line the stems. Loved by hummingbirds and cut flower aficionados alike. Rich soil in full sun in a protected position- a south or west facing wall is ideal. Freezes to the ground below 20ºF- re-sprouts in spring. Forms an expanding clump to several feet across. A fun genus to experiment with in our climate. Rated as zone 7 in its native high elevation South Africa. We think its more like 10ºF in our climate. Plant with royal red Lobelia tupa and Rosa ‘Bengal Fire’ for a red extravaganza. Excellent performance at the Oregon Coast. Somewhat deer resistant.
Watsonia pillansii
This is one of the hardiest species of Watsonia Lily. It forms large evergreen clumps of spikY foliage to 3′ tall. In early summer 6′ spikes of tubular brilliant orange flowers are stunning. They bloom for weeks. A protected location such as close to a south or west facing wall. Capable of freezing to the ground in extreme cold (below 20ºF) but regrowing vigorously and still blooming in late spring to early summer. Rich, well drained soil with regular summer moisture. If allowed to go completely dry in summer this as with other Watsonias will go dry dormant. It returns with the first rains in autumn. Amazing cut flower. Mulch your clump in autumn. Wonderful South African perennial that is glorious at the Oregon Coast. To 3′ wide eventually.
Watsonia x pillansii ‘Coral and Hardy’
We love Watsonias but the most successful climate is truly on the coast. This form is seed from a persistently hardy, well blooming plant that has survived in Portland. The majority of these seedlings will be coral/ orange/ light pink. To 20″ tall forming clumps in RICH, well composted soil in full sun. Regular summer water increases both the growth rate and the cold hardiness. Larger more established clumps are hardier to cold. Amazing cut flower that will produce several dozen spikes off of one good clump. Mostly evergreen. Foliage looks burnt below 20ºF and can freeze to the ground. This winter growing bulb is also immensely drought tolerant with a period of summer drought inducing dormancy. Place in a warm, protected location Near a south facing wall or fence. Mulch for the first few winters with dry leaves. Place in a location where summer dormancy is not an issue. Very fun to grow South African bulb. Excellent performance at the Oregon Coast. Not bothered by deer or elk- well the elk might step on them but they won’t eat them. Fantastic cut flower and clumps become huge there.
Xera Plants Introduction
Whipplea modesta
Yerba de Selva or whipple vine, a wonderful small scale evergreen native ground cover. Related to Hydrangeas but this trailer is actually very droughtadapted.e In late spring clouds of small white flowers , Scrambling plant to about 8″ tall and 2′ wide. Full sun to considerable shade. From Portland south this is a common understory component of the herb field. It grew happily in our back 40 where I grew up. There it made pretty scrambling patches between Vancouveria, snow berry and hairy honeysuckle. Often you would see our native columbine ( Aquilegia formosa) as an associate. Its very drought adapted when established but it improves with a few soaks over summer- never perpetually wet and never hot and wet. Otherwise an easy native that should be grown a lot more. For use as a small scale ground cover plant on 10″ centers. It will also gracefully trail over rockeries and walls. Butterflies adore the flowers. Competes well with invasives. Some deer resistance. It may be cut back in early spring to refresh. Once native in the Portland city limits. This is a great native understory for Arctostaphylos, which is frequently seen in the wild. Oregon native plant.
Wyethia angustifolia
Mules Ears are rare in cultivation. These cheery bold perennials make the transition of our wild flowers from spring into real summer. So named for its long leaves it forms very permanent spreading colonies in clay soils in habitat. The brilliant yellow sun flower blossoms rise up on sturdy stems directly from the ground. Each ebullient large flower is about 4″ across. Blooms appear from late April to early June. This plant usually finishes blooming just as summer drought commences. Its a memorable sight in wild meadows where it blooms simultaneously with native Rosa nutkana and Farewell to spring (Clarkia amoena var. lindleyi) and Giant blue eyed mary (Collinsia grandiflora). Wonderful cut flower and immediate and popular pollinator perennial. This plant was once very common in the Willamette Valley but civilization has immensely shrunk its native range. Good, long lived garden plant that goes summer dormant quickly after blooming has ended. The leaves turn gray and brittle and can easily be removed then. Give it a summer rest w/ little to no summer water once established. Full sun to very light shade. Water to establish its first season then none in subsequent years. Fun to grow and LONG lived. To 14″ in bloom forming a plant several feet across. Moderate deer resistance. Native to the Portland city limits. Very slow to finish in a salable size. Patience. Limited quantities. Oregon native plant
Yucca (nana) hermmaniae
Adorable and rugged little dwarf Yucca from southern Utah. Tight round quills are decorated with filaments on the leaf edges. Not a friendly guy and very slow growing. Forming spheres of spikes to 1′ across and multiplying to produce colonies with pups. Full sun and very well drained soil of average to poor fertility. Requires excellent air circulation- no crowding. Plants that are smooshed with little air circulation protest heavily and it then takes a while for recovery. Open and free in rock garden conditions produces the happiest plants. At home nestled with boulders or as a finer texture element with Agaves. In time it produces adorable and conical shaped hoods of flowers- a gnome wedding. Excellent in containers- open, well drained containers. Light summer water during hot weather seems to speed growth. Locate away from paths. Owwie. Strongly deer and rabbit resistant.
Yucca rostrata
Beaked Yucca does fantastically well in our climate and is one of the Yucca species that will form a dramatic trunk. Blue thin leaves radiate out in a perfectly round orb. Slowly rises to 8′ tall in our climate. Full hot all day sun in a warm position. Very well drained soil with light summer water during the hottest stretches to encourage growth. Occasionally, with age 4′ spikes appear holding large trusses of ivory flowers. Perfectly hardy to cold, way below 0ºF. Avoid cold wet sites- to really do well it needs heat and exposure. Not prone to bacterial leaf blight that affects other Yucca species. Good air circulation. Lives happily in large containers for eons. Focal point in many of the best gardens in our region. High deer resistance. Evergreen.