Q: I have a beautiful Knock Out rose in a planter and don't know how best to store it during winter and keep it healthy for next spring and summer. We have a basement and a garage (colder). Do I cover it with plastic? Do I water it during the winter?A: Knock Out roses are winter hardy, so the only thing you have to deal with is the phenomenon of an exposed planter getting much colder than Knock Outs growing in the ground. Do not put it in the basement; do not cover with plastic. A garage should be OK, provided you water it occasionally and, if there are no windows, get it out into the light in late winter.I have had success with potted winter-hardy shrubs by sinking the pots in the ground in a nonwindy site. Other tactics are to place the planter on the ground, not a balcony or deck, immediately next to the north or northeast side of a building.

Q: We have a large city perennial and annual garden in Philadelphia, with some large junipers. We want to mulch for winter, as has been recommended, but what should we put down?A: There are two reasons to mulch for winter. The primary one is to minimize the freeze-thaw cycle of yo-yo temperatures. This kind of mulching should be done after the ground freezes for the long haul, rarely before late December. A light mulch is called for — straw or pine needles or evergreen branches.A secondary reason for winter mulching in temperate regions is to try to keep marginally hardy plants from dying.Send questions to Michael Martin Mills, The Inquirer, Box 41705, Philadelphia, PA 19101 or gardenqanda@earthlink.net. Please include locale.