Douglas Spirea (Spiraea douglasii)
Douglas Spirea is a gorgeous, and very drought tolerant, native wetland shrub. While it does have a deserved reputation for being thicket forming, this tendency can be mitigated by greatly reducing the water it has access to. Much of it's aggressive growth occurs in bogs and wetlands where it has access to year around water. Despite being a plant of wet places, this plant is capable of growing in full sun, in the height of baking summer heat in the PNW without irrigation. Douglas Spirea is tolerant of many soil types and is just as happy to grow in part shade as it is in full sun. It's an excellent plant for rain gardens, hedges, fencelines, along roadways, and neglected corners where you want something nice to look at.
I have a couple planted with a few young Scouler's Willows in a section of pasture that used to turn into a flowing stream each Winter. They have effectively stopped the water run-off. Now the water pools for a short time, and is able to soak into the soil in place! This is a location that bakes in the summer heat every summer, and they don't even flinch.
Bumblebees adore their fuzzy pink flowers. Song birds love it for it's seed in the Fall and the cover it offers through the rest of the year. And, it's a butterfly host plant for Lorquin's Admiral, Spring Azure, and quite a few moth species, in addition to, providing nectar to butterflies. I've even seen hummingbirds feeding from the flowers!
Because the seeds are so small (like elongated dust) it is impossible to count out individual seeds and are instead sold in weight increments of 40mg (200+ seeds) and germination instructions are included.
Douglas Spirea at a glance
- Average growth dimensions - 2-8 ft tall x 3-8 ft wide
- Dormancy - Winter dormant
- Plant type - Native shrub
- Sun - Full sun - part shade
- Water - Wet - dry
- Flowering time - June - September
- Flower color - Purplish-pink
- Soil preference - Highly adaptable