Question
QUESTION: Hi,
This is new to me. I have hybrid tea roses (2 plants) and a knock-out rose in a bed. The tea roses have brown edges and some of the buds (which I cut off today) were very brown. Some of the leaves were spotted yellow and black. I treated today with a baking soda/canola oil and water mixture (poured over leaves). These plants are 2-3 years old. I removed most of the yellow leaves. This occurs several times a year and generally treat w/a systemic feed which cures it. But this time the flowers look so bad. Any ideas what is going on and how to organically treat?

ANSWER: There is a tiny insect called a rose midge and it lays it's eggs at the base of the buds. When the eggs hatch they damaged the buds and they are killed and so will turn brown. Cut the buds off and throw them in the garbage as they contain insects. You will have to wait until the next set of flower buds to grow to get flowers.  The yellow and black is a fungal disease called black spot. There is no cure for it all you can do is keep it under control. To my knowledge there is no organic mixture that will help. The best you can do is use a dormant oil and sulphur spray that they use on fruit trees in the spring. The instructions for roses are also on the package. Be careful of systemic feeds as some roses will re-act to them as they are very strong. Use a mulch all around the base of the roses to keep the roots cool as high heat on the soil causes the roots to go under stress. Next spring cut back your rose bushes to about 18 inches tall and this will get rid of a lot of the fungus. Then use the spring dormant spray and you will see a big difference.

---------- FOLLOW-UP ----------

QUESTION: As we just had torrents of rain do you think most of the midges got washed away? I will cut off any bad roses/leaves that are left today.

Answer
Midges are nice and cosy inside the rose buds so they don't mind the rain. After the mother midge has laid the eggs in the flower buds, she then dies so when the eggs hatch they stay in the buds and eat the insides out killing the bud. When they are mature they then drop to the ground and start the life cycle all over again. You can see that rain has no effect on them.