By Jeff Rugg Creators Syndicate Inc.
Question: I have read your column and would like to add your answer to the question why the rose plant did not flower again despite new branches. You mentioned that it could be the type of rose or the lack of fertilizer.
I had this problem in New England too and found that I had a mosquito (a tiny flying insect that you can’t really see) invading the newly forming bud. So after the first blush you suddenly don’t see any more flowers, but if you look closely you can see a dried or dead bud on the new branches. You will need to spray for the insect or use a systemic insect repellent. I also tried blue cups next to the plant that had been sprayed with cooking spray inside and out. This seems to work too, but the systemic stuff is better.
Answer: You are right. The rose mosquito is a tiny insect that most people won’t even notice. The adult is a mosquito, and the larva is a tiny larva that is only about a millimeter long. The lifespan in summer is very short, only about two weeks. The female lays eggs on the side of the bud at the end of the branch that will become the flower. The larvae eat the bud. There can be a dozen larvae in a single bud. They mostly fall out of the bud to pupate in the ground, but some can pupate in the bud as well. The last group in autumn remains dormant until the following spring.
Once the mosquitoes are in a flower bed of roses, they won’t go until the controls are used. A systemic insecticide applied early in spring and applied throughout summer is the best control. Viewing the ends of all rose branches and pruning any affected branches should be done every few days. All the branches with black leaves at the end have already had the mosquitoes that are now in the ground or have already grown out. In the fall, the top few inches of mulch or soil should be removed and replaced.