If you are growing any other types of rose than the Knock Out Roses, and other low-maintenance modern shrub roses, your roses will probably require treatments for fungus and other diseases.
So, if you grow Hybrid Tea Roses and other roses which are highly suceptible to fungus and disease, you can follow the guidelines below:
- Keep a chart of when you spray roses with fungicides. You should spray your roses with a fungicide on a schedule of every 10 to 14 days. This is easy to do if you keep a sprayer on hand that is specifically for fungicides.
- Use a different fungicide every other week to make it less likely that the your roses will build up a resistance to one particular kind of fungicide.
- If any leaves on your roses develop black spot, or start to turn yellow from a disease, pull them off and discard them. Any diseased leaves that have fallen to the ground should also be removed and discarded. The onset of black spot is usually caused by too much water on the leaves, either from nightime irrigation or during extended overcast periods when the dew is not dried off by the sun. Manzate is one good chemical useful for killing black spot spores. If black spot spores are present, you must first eliminate them by picking diseased leaves off.
- Regarding mildew, good air circulation is the best preventitive measure. Space you roses sufficiently in the garden to prevent mildew and other diseases. Proper spacing of roses in the garden help to keep plants dry, not allowing disease spores to take hold. Aside from Manzate, Compass and Banner-Maxx are two other good fungicides. These are quite expensive chemicals, however the the bottle goes a long way because of the small amount needed to mix solutions. If you cannot find these fungicides or don't want to afford them, any 'broad spectrum' fungicide listed for use on roses will do.
- Alternatively, you may choose to use an organic product, such as those containing Neem oil, to control fungus on your roses. Neem oil also prevents, controls and kills many harmful insects. Whatever fungicidal product(s) you use, remember to switch the type at least every other spraying.
