Menzie’s Larkspur is one of the most widespread species west of the Cascades. That doesn’t mean it easy to grow, and as a crop it can be a pain, That said its one of the ultimate spring flowers and its lost immense amounts of its range in the Willamette Valley to development. This widespread perennial is a grassland Delphinium that can be found in oak woodlands with Dodecatheon hendersonii, and Plectritis congesta and Romanzoffia californica. The soils that it inhabits run the gamut from sand near the beach to xeric clay in and around the Willamette Valley. This can be a tricky species to establish, my best advice is to double dig a wide area where there is very little competition from other plants. Add a small amount of all organic fertilizer to the hole. Water in well and water again once a week until June. Then you can permanently taper off. That means in subsequent years it will rely on natural rainfall alone. Upright perennial to 20″ tall multiple brilliant blue flowers often with a lighter bee. I’ve also seen them in a deep black/blue velvet purple. Sets seed and goes dormant in mid-summer. Its very very important to protect the emerging plant or seedling from snails and slugs. Bait heavily when you first see growth in late winter. Though widespread but no longer common this Delphinium seems to adapt best to cultivation with a light gravel mulch. This protects the plant from slugs and provides a perfect medium to germinate the seeds. Very popular pollinator plant visited by all sorts of bees, fly bees, hover flies, butterflies and more. The seedlings are conspicuous and the leaves mimic the parent plant. Full sun to light shade. Oregon native plant.
Genus: Delphinium
Delphinium trolliifolium
Giant Larkspur or Cow Poison, I prefer the first common name for this stunning large growing native Delphinium. In vernally wet sites to moist upland sites it forms large spectacular colonies. In late spring and early summer stems that soar to nearly 4′ tall are loosely decorated with marine blue flowers with a lighter central bee. In habitat its common associates are Oregon Ash (Fraxinus latifolius) and Oregon white oak (Quercus garryana) where it can be found in the shade of these deciduous trees. The one variable with this Delphinium is that it is found in cool places- never hot and dry. These shadowy environs can make this plant hard to spot even in full bloom. Often they will be in standing water during the winter months and they are adapted to very heavy wet clay soils. In cultivation the need for moist conditions continues and it does appreciate at least an application of all organic fertilizer and compost at planting time. Keep it well watered through its bloom cycle, then it can go drier but never dust dry- in time it can handle much less irrigation. An annual mulch is beneficial. Wonderful, bold cut flower , but its loved by pollinators as well ( what is it about blue flowers? ). Forms spreading colonies in time. Give it room to stretch out. Its often found with our native Cow Parsnip (Hieracleum maximum) and great Camas ( Camassia leichtlinii) in habitat. This could easily be replicated in a garden. Native to the Willamette Valley into the Columbia River Gorge. Once widespread in the Willamette Valley its territory has shrunk precipitously. Long lived perennial. Very good deer resistance. Extremely showy in bloom. Oregon native plant.
Delphinium nudicaule
Brilliant orange/red tubular flowers each with two spurs on the rear of the flower. They appear to be swarming around the green wiry stems that support them. To 20″ tall, blooms rising from a basal rosette of leaves. Blooms May-July in Portland. Somewhat tricky southern Oregon native wildflowers that needs a bit of care and correct siting to establish and become perennial. Rich, well drained soil with light but consistent summer moisture. Native to very steep slopes and cliffs with excellent drainage but with groundwater in the form of seeps near by. Wild areas, gravel gardens for the ultimate wildflower effect. Established plants will often re-bloom if spent flower spikes are removed. Hummingbirds. Moderate deer resistance. Oregon native plant.