Those of you that live in humid and rainy conditions no doubt are constantly trying to keep your rose bushes and peonies healthy.
I am constantly fighting black spot mildew on my roses. I have tried eco-friendly products that contain neem oil, as well as more toxic varieties. The best cure is to have sun and some hot dry weather, which unfortunately we haven't had a lot of lately. Recently I learned that at the International Rose Test Garden at Washington Park in Portland Oregon, the botanist has had a difficult time with keeping black spot off of their roses as well. While watching the news tonight, he made the recommendation that if you have a 4 hour window without any rain and full sun, you can spray the roses with either milk or a mixture of 1 tsp. of baking soda mixed with one quart of WARM water and a few drops of liquid dish detergent. This will change the pH balance within the plant and help stave off black spot on the healthy leaves. It is best to hand pick and remove the infected leaves first however, as well as pick up any diseased leaves that have fallen on the ground. Do not put them in your compost bin. You do not want to infect your nice compost soil with the fungus!
I am eager to try this out on my 4 rose bushes and see if it makes a difference.
My roses are doing great. My "Knock-Out" variety is an explosion of bright pink color and will go all summer. My "Oklahoma" is thriving too, with huge blooms.
ReplyDeleteI planted peonies from bulbs this year, but am not sure if we will have any flowers this year on them. I don't think we will have this problem with the dry climate, but I that is very helpful!
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