Scarification: Soak in cold water, let stand in water for 24 hours
Stratification: warm stratify for 120 days, cold stratify for 90 days
Germination: sow seed 1/16" deep, tamp the soil, mulch the seed bed
Other: some germination may be delayed until the following year
With its beautiful flowers, decorative hips, and vibrant fall foliage, the Rosa pisocarpa, also known as cluster rose or swamp rose, is a stunning addition to any garden. Native to western North America, from British Columbia to northern California, this shrub thrives in moist habitats, growing up to 2.5 meters tall.
The stems of the Rosa pisocarpa can be dark red or blackish and are adorned with straight, paired prickles at the nodes. The leaves are made up of several toothed oval leaflets, with the terminal leaflet reaching up to 4 centimeters in length. The inflorescence holds up to 10 flowers, each boasting pink petals that can be up to 2 centimeters long. Following the blooms, the plant produces rose hips, which are pear- or egg-shaped and about a centimeter wide. These hips are borne in clusters and are particularly striking in the fall and early winter when they are red or reddish-purple, contrasting with the yellow foliage. The fall foliage of the Rosa pisocarpa can display hues of yellow or dark red, adding to its overall beauty.
Not only is the Rosa pisocarpa visually appealing, but it also offers various practical uses. The fruit is a versatile ingredient, suitable for both raw consumption and cooking. It can be used to make delicious jams, jellies, and even fruity-flavored tea. The seeds of this rose species are a good source of vitamin E. They can be ground into a powder and mixed with flour or added to other foods as a supplement. Additionally, the shoots of the Rosa pisocarpa can be used to make a tea-like beverage, while the young tender shoots are edible in the spring when peeled.
In terms of ecology, the Rosa pisocarpa has a wetland indicator status of FAC for the Pacific Northwest and FACU for California. It thrives in riparian areas, roadside ditches, powerline right-of-ways, fencerows, hedgerows, wetland buffers, and woodlands. This plant is commonly used in wetland restorations and native plant landscaping. Its thorny thickets and numerous hips provide shelter and food for birds and other small wildlife, contributing to the overall ecological balance. However, it's worth noting that deer often browse on the new stems and foliage of the Rosa pisocarpa.
A particularly fascinating aspect of the Rosa pisocarpa is its relationship with gall-making wasps. This rose species hosts two species of gall-making wasps belonging to the Cynipidae family and the genus Diplolepis. These wasps create intriguing galls on the leaves and stems of the Rosa pisocarpa, adding visual interest to an already captivating plant.
Overall, the Rosa pisocarpa, or cluster rose/swamp rose, is a resilient and visually stunning shrub native to western North America. With its beautiful flowers, striking hips, and vibrant foliage, it can be a valuable addition to gardens and landscapes. Additionally, its practical uses in cooking and its ecological benefits make it a versatile and beneficial plant.