Trials are Underway for Propagation of Shade-tolerant Groundcover Plants

It’s that time of year again when the weather starts to cool and the rain is inescapable; and also the perfect time of year for land managers to sow native seeds at restoration sites. 

The Environmental Services Watershed Revegetation Program team works on natural area restoration projects with other City of Portland bureaus and many public and private groups. The restoration work improves water quality, controls erosion, reduces stormwater pollution, and enhances fish and wildlife habitat.

With hundreds of acres of English ivy and other invasive species removed, restoring native groundcovers can be a challenge.  Since most shade-tolerant, native groundcovers are not available commercially, the Watershed Revegetation Program has partnered with Metro and Clean Water Services to determine the best species and propagation techniques to create a region-wide seed source. They collected native seeds throughout the summer of 2012 at different sites around Portland, mostly in Forest Park.  Some of the species targeted were Pacific waterleaf (Hydrophyllum tenuipes), candy flower (Claytonia sibirica), fringecup (Tellima grandiflora), and largeleaf avens (Geum macrophyllum). 

In addition to sowing these seeds at restoration sites, seeds were sown in experimental plots this fall. Germination success will be measured for different methods and at different application rates, and data will be collected next summer. Results will be shared with Metro and Clean Water Services, who are conducting similar trials. Stay tuned for the results; we can’t wait to see what pops up in the spring!