Paula from SE Michigan writes
“I recently purchased and planted two Blushing Knock Out roses. I live in SE Michigan and the nursery told me to plant them right away, which I did this week. So far, they look great. Here’s my question: I ordered one more which is not scheduled to ship until Nov. 9 and am wondering if I should also plant that one or keep it inside until spring? Also, should I cover the other 2 for the winter (I put a lot of mulch at the bases)? Thanks in advance!”
Nov 9 is going to be another month away from when the nursery told you to plant your knock out roses “straight away” so you might be pushing it. I’d play it safe and keep it in your garage until spring. Water it once a month and it should be fine.
SE Michigan is considered USDA zone 5 (some say USDA zone 6 now due to the climate getting warmer) and from research I’ve done there are mixed opinions about whether to protect knock out roses in winter in zone 5; some folk have not used any winter protection and their knock out roses have suffered no dieback and gone on to flower beautifully. Others weren’t as fortunate when they didn’t use any winter protection in zone 5 and their knock out roses died back to the ground and a couple died completely, so to be on the safe side I would cover your knock out roses for the winter but wait until after one or two hard freezes before protecting them.
To winterize your knock out roses, use a rose collar around the base of each rose, around 8 to 10 inches high, and fill it with either mulch, shredded leaves or soil. You could make the rose collars out of cardboard, several sheets of newspaper or chicken wire. If you didn’t want to muck around with this or don’t have the time, these ready-made Rose Collars do the job really well, can be used over and over again every winter and are reasonably priced for the use you get out of them.
If your knock out roses are situated in a windy location, you might want to tie the canes together with some garden twine to stop them from thrashing about and breaking off in the winter winds. Remove the mulch and rose collars in spring.
Overwintering knock out roses in climates of zone 6 and colder will go a long way towards ensuring their survival through the harsh conditions of this season