Double Knock Out Rose Problems

Nice & Easy Double Knock Outs by perennialpal

TheGardenLady received this question from Wendy.

I live in eastern North Carolina and I have several double knockout rose bushes and they have been beautiful. This year I pruned them back in early spring and had a magnificent show – we have had several hard storms lately and now there are no blooms on the bushes. There are a lot of dead heads. Should I pinch off all of them or should I leave them be? I dont remember having to do this after first pruning in the past – but I also thought I had more blooms and for a longer time through out the summer.

When one has a hard rain it knocks a lot of flowers off. The rain did a job on my peony flowers as well as my Knock Out Rose flowers. Perhaps someone should invent a rose umbrella to protect the flowers from hard rains. They do sell umbrellas for Peonies – but these umbrellas are really to protect the peonies from too much sun. Cricket Hill Nursery sells peony umbrellas from Japan (see here).  Too much sun will make the peony flower have a shorter bloom period. So gardeners do have to work with the elements.

Back to your roses. Knock Out Roses are bred to not have to dead head them.  See here.  The petals pretty much fall cleanly off. But I think the part that is left does not look pretty, so I cut it off back to some leaves.  It seems much cleaner looking to me. You will have to decide what you want to do – to dead head or not to dead head. Just know that you don’t have to deadhead. I let the rose rest a little after its initial burst of blooms. The next time I have to water the roses, I add a little fertilizer that has a high phosphorus content to the water in a watering can and pour it around the roots of the bush.

I loved Schultz’s Bloom Plus which had the highest phosphorus percentage; but Schultz gave up this fertilizer component of their products. I was so upset to learn they no longer are making their Bloom Plus nor did they tell me if any other company has taken over the manufacture of it. So I went to all the local nurseries to see if any had this Bloom Plus product left on their shelves. One of the best nurseries in my area, knowing how good the product was, had ordered a lot; so I bought up a lifetime supply- it doesn’t spoil and one uses so little of it per gallon. Of course, there are other brands that make rose fertilizer or fertilizers for optimum flowering of plants. I just never thought they were as good as Schultz’s.

Double Knock-Out Roses by Charity D

I have seen that with this added fertilizer encouragement each time I water my roses, I have a great flower show. But even without the extra fertilizer boost, Knock Out Roses will delight you with continuous bloom throughout the summer. Just let it catch its breath.