I live in zone 6A, I was told by my nursery that I can mulch or cover or cut back close to the ground. Cutting back will back them bushier next year. What are Your recommendation.

I would mulch them and then trim off any winter kill in the spring. It is hard to hurt a Knock Out

Hey Tomba

I too live in a 6a zone and just 2 years ago in the month of November we went from 70 degrees to 10 in less than 24 hours, needless to say this caused extensive damage to ALOT of trees and shrubs here. Not only did my boxwoods, spireas and Spanish brooms get dinged pretty hard but so did my knockouts which surprised me seeing as how iron tough they are, anywho, I'm still in the process of cutting out the dead ( off the top of my head I figure 30 plus of them ) but the first few were done that following spring and since what little I know about roses is most are scions on rootstock, I didn't want to cut too low. But I did notice that those I cut to near ground were just as healthy and robust as those I hadn't got to yet - even though the latter had noticeable dead branches - but by no means ' bushier' .

I will offer this advice though, get some tough leather gauntlets not gloves, those boys bite hard!, the kind that go to the elbows and NOT sold at big box hardware stores. My wife bought me a pair from Lowes that were too thin and tight. Lucky for me a wielder friend of mine gave me a pair that were too thin for HIS job!

Hope this helps.

J.R.

I have never grown Knock Out Roses because they are grafted. Non-grafted roses (called self rooted) can die to the grown and come back from the root year after year. But if you are growing grafted roses, including Knock Out, mulch heavily. As in foot deep mulch. Prune in the spring after the plants leaf out.

If you prune a Knock Out Rose (or any grafted rose) to the ground, you will have the rootstock next spring (because you threw away your plant). If you prune in the fall, you are asking for a lot of dieback. The pruning doesn't cause the dieback, the cold does. But if you prune 2 inches off and the cold kills 2 inches, you've lost 4 inches of growth. If you prune in the spring and 2 inches have frozen, you can cut that two inches off and end up with a bigger plant.

I live in zone 6 but here in the high desert, plants don't get buried in snow because it doesn't snow all that often. We are dealing with dry cold. It can take a plant out fast. Grafted roses don't survive.

I notice in our database, for one of the Knock Out Roses it lists zone 4b and for another it lists zone 5 and higher. I'd do as suggested and mulch, mulch, mulch and wait until warm weather in spring to do any pruning. http://garden.org/plants/searc...