Q. After pruning my roses, is there any special winter fertilizer I should apply to my bushes? In addition, what should I treat the bare stems to minimize the Rose Rust, and Black Spot this year?
Ans. While there isn’t any special type of winter fertilizer for roses, they do need to be fed but it’s a bit early to start. I’d wait another month or when the new growth is about one half inch long to make my first application. There are a lot of great fertilizers available for roses, so no one brand or type is the best. Dr Earth is a fabulous, organic fertilizer. Miracle Grow is perfect for those that love to fertilize often and for those that fertilize infrequently like me, there is Osmocote. Osmocote is a time-release fertilizer that is applied every four months. Roses are heavy feeders, so whatever fertilizer you choose, reapply it regularly right through October. To start your rose disease control program. I’d spray the canes with Bonide Copper Spray but first strip off any of the remaining leaves and remove all the debris from under the plant(s). The spores from Black Spot, Rust and Mildew can over-winter in this material. This should be done sometime in the next couple of weeks. Ideally, before the new growth is too far along. This is a preventive measure to remove any of the local sources for the diseases. It sort of sanitizes the area. The spores of Rose Rust, Black Spot and Mildew are air borne, so there is a better than average probability that they’ll return with wet, damp and rainy conditions. The length of time moisture remains on the leaves after the sun goes down triggers the problems. The damaged leaves show up about ten to eighteen days after being infective. Last spring, the rose diseases were a big problem almost until Mother’s Day, because of the wet spring we had. So applying a rose fungicide to foliage is recommended and again there are a lot of choices. There is no fungicide that will eradicate the diseases, they only control them: hence, depending on the weather, repeat applications must be made until the rainy season ends. Also keep in mind, to be effective, the fungicide must be on the foliage before the moisture arrives not afterwards. This can be challenging with all the other things that can be happening during a week. My solution is Bayer Advance All In One Rose Care. It feeds my roses, provides a systemic fungicide for six-week control of the rose diseases, and finally as a bonus takes care of the Aphids, Thrips, and Spider Mites. Bayer Advance All In One Rose Care is available in a liquid, which doesn’t have to be sprayed on the foliage and easy to apply granules. Unfortunately, Bayer All In One Rose Care is not an organic solution and I only use it in the spring until the rainy season has concluded. You can certainly separate these into individual tasks but I prefer one and done.
Buzz Bertolero is Executive Vice President of Navlet’s Garden Centers and a California Certified Nursery Professional. His web address is www.dirtgardener.com and you can send questions by email at dirtgarden@aol.com or to 360 Civic Drive Ste. ‘D’, Pleasant Hill, Calif. 94523 and on Facebook at Facebook/. com/Buzz-Bertolero
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