I live in Squamish BC Canada & have several of the above plants which have been left in the ground & planters over the Winter.They seem to still be alive but looking very weathered & sad with brown wilting spikes. I'm wondering if I can give them a haircut to remove all the wilted, dead & brown spikes etc. Normally they don't survive the Winter so I really don't want to damage them now by cutting them back. How can I clean these up. Thanks for your help.