Seeing fresh red leaves on your rose bush (Rosa) might be a signal that the bush is healthy and growing, depending on the time of year. When green leaves start to turn red, however, it’s likely a indication of a larger problem that could be harmful or fatal to the plant. Roses rise in U.S. Department of Agriculture plant hardiness zones 3 through 10, depending on the number.
When you notice fresh leaves appearing on the stems of a rose bush, it’s typical for those leaves to be red or burgundy. They frequently stay this color until they get close to full dimension, when they start turning green — often from the inside out, sometimes making it look as if they have reddish tips. This is actually the normal growing process for many rose bushes, and it ensures the bush is healthful.
Nipped from Jack Frost
If green leaves start looking reddish or reddish-brown around the edges in late spring or fall, then it’s possible they’ve been damaged by frost. Frost sometimes shows up suddenly after the rose bush has started to climb in the spring, or sooner than anticipated in the autumn. This won’t necessarily damage the plant; a single frost that nips the edges of the leaves isn’t likely to kill the rose bush. Repeated spring frosts might be a problem, but in the autumn, your bush likely goes dormant as the weather cools and loses its leaves until spring.
At the height of the growing season, red tips on leaves which already turned green likely are a indication of rose rosette disease. This illness will destroy the plant, as there are no treatments for rose rosette disease as of November 2013. The illness started in wild roses subsequently traveled into cultivated roses. It turns out the leaves red, or a mixture of red, yellow and green, while creating the stems fragile and unusually thorny. The leaves also may look curly or twisted.
How It Spreads
Grafting roses can disperse the rose rosette disease, however, the most frequent culprits are tiny bugs: eriophyid mites. The mites are nearly microscopic in size, therefore it’s unlikely you’d notice them — you’ll observe the rose rosette symptoms first. The mites are also difficult to control as routine insecticides have little to no impact on them. The mites do not have wings, so they usually stay contained to a small region, but they often are blown to other plants from the wind. When you suspect rose rosette disease — along with its normal accompaniment of mites — it’s best to dig the plant up and set it in a fragile trash bag for disposal with your trash. Do not add it into your compost pile. Disposing of this plant helps remove the disease along with the mites, hopefully before any nearby roses become infected.