Rubus pentalobus (Emerald Carpet)

I have a very steep hillside covered with Rubus that I really love because the texture of the plant is somewhat sticky and allows safe walking on the hillside. The ground cover has been growing for about ten years and last winter, for the second time, we had a severe early cold (mid November 14 degrees F) that froze the top few inches of the Rubus. The last time this happened I just left the plants alone and by the end of the summer there was new growth coming through the dead tops. Does anyone know if I will speed up the recovery if I use a string trimmer to whack off the dead tops?
Location is western Washington State in Cascade mountain foothills.

 

My gut feeling is yes. Certainly other evergreen groundcovers like St John's Wort recover much more quickly when trimmed back than when left to recover from winter damage on their own. So do many evergreen shrubs.
I think that cutting back the damaged stems stimulates new growth more effectively than dieback does, perhaps because it removes hormones or other chemicals in the upper branches which may be suppressing development of new side buds. Removing the winter burned leaves also exposes dormant buds to light, which helps stimulate their development. Sheared back plants also looks better sooner than those left to recover on their own. Once the brown, damaged leaves are gone the plants just look like deciduous plants in spring; they don't catch your eye like a patch of dead looking leaves does.

 

I'd like to see an organized experiment, with controls and measurements being employed before I accepted that cutting dead tips of a frost burned planting makes it recover faster.

 

Geezer840 is in a good position to do a study such as Ron suggests. With a large area of Rubus, he (or she) can shear one or more sections and leave other areas untrimmed. By late summer it should be clear whether there are aesthetic, or other advantages to one method over the other. My personal experience is mainly with ferns and St John's Wort, both of which grew back bushier in the years when I cut back the winter damaged plants.

 

I agree with your suggestion but... We just returned from a vacation and I checked my spam e-mail and found I missed your response until now. I thank you for your suggestion but I've actually already cut the rubus down to approximately 3-4 inches. There are some areas I was unable to trim so there will be limited opportunity to compare. I can say that in just the two weeks since cutting we have had relatively mild but occasionally rainy weather and I can see quite a few buds coming out on the trimmed areas as well as from the dead sections untrimmed. I will update this with a response to you later in the summer.

 

Well, after two weeks I can see new green growth on both the cut areas as well as the areas left uncut. The only difference that I can see so far is that the growth on the uncut areas is taking place about 6-7 inches above ground versus right at the ground level on the cut areas. I will try to update again in a month or so.

 

make sure you take some photos for your future reference (and maybe you can post them here, too)