Travis wrote:

I'm looking for a low growing groundcover that spreads quickly but is not
invasive. I want it to spread quickly so I don't have to buy too many
plants. The plan is for the ground cover to replace (by shading them
out)native grasses and weeds in an area planted with immature evergreen
trees and shrubs.

--
Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8b
Sunset Zone 5

Travis, they are not sold as a "groundcover" but there a number of hardy
geraniums that would do the trick. They grow quickly to form large spreading
clumps, flower for an extended period and are not what I consider to be
invasive, although some will self-seed freely but are easily removed. Pay
attention to heights - some geraniums can get fairly tall and rather lanky -
so I'd stick with the lower growing types to get the best effect. A few that
I'd recommend:
Geranium x cantabrigense 'Biokovo'
G. cinereum 'Ballerina' or 'Lawrence Flatman'
G. clarkei cultivars
G. himalayense 'Birche's Double'
G x oxonianum cultivars
G. x riversleaianum 'Russell Prichard' or 'Mavis Simpson'
G. sanguinem cultivars

pam - gardengal