In early May I decided to do some container gardening on my rooftop, and perhaps I bit off more than I could chew. In "Jardin Majorelle Blue" pots I planted two tree roses, which were perfect little orbs and had the most deliciously sweet-smelling white blooms for two months. That's all over now. We have had nearly 30 solid days of rain in NYC, and the black spot fungi and aphids have taken full advantage of the conditions while I have torn out all of my hair. Within the past several days nearly every visible leaf has been affected, and the blossoms look very sick. The leaves are not pierced or falling off yet, but I know that they are as good as dead. How far should I prune back, or do I just need to let go and buy two more?
Well... if it makes you feel any better, you're not alone... I would refer you to the following recent thread where some very smart information is shared by some very smart people. This has been a bad year for black spot... has changed my whole outlook on roses. Take heart, don't give up! http://www.gardenstew.com/about14707.html
See if you can find Bayer 3 in 1 Systematic Rose food. It may now say "all in 1, but it is by Bayer. It is a liquid you mix with water it feeds, prevents or controls roses diseases, and protects against insects. I know our WalMart sells it in the garden center.
Here in the South we battle fungal diseases every year. Bayer all in one helps a lot. I would keep treating every six weeks and they could revive. I have several that came back.
Well it gives me hope to hear its commonplace south of the Mason Dixon Line. Although I would bet it has been even wetter here this year. I will keep applying the spray, but I don't think I can use another Bayer fertilizer, as I have already given the plants Bayer food for the month. I am also assuming I cannot prune all of the diseased leaves, since it would mean defoliating the entire plant? And I am assuming after every rainfall I should buy yet another bottle of spray to apply? Thanks, everyone.
I use a general fungicide spray on the leaves as well as the Bayer. Hope your rain takes a break and your plants have a chance to enjoy some sun. It takes a regular program of spraying according to the type of spray you buy, especially on new growth.In the case of a tree rose, I might prune back to within 6 inches of where they branch off the main stem. Be sure to clean any leaves that fall in your containers. Good luck!
