Powdery mildew
Hi, I have an indoor rosemary plant which I got recently; within a few days it had powdery mildew on it. I have many house plants and have had no issues with mildew. I have also had rosemary plants before, with no mildew. I have tried spraying it with a fungicide (Safer's, I think) which really only gets rid of the mildew for a few days. Does anyone have any suggestions for really eliminating the mildew, rather than just trying to keep it at bay?? I like to use fresh rosemary in cooking, and neither mildew nor sulfur spray residue are very appetizing!!
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(post #12792, reply #1 of 6)
I would be terrified to eat anything sprayed with fungicide...what are the active ingredients?
zone 6 gardening in the woods with 30,000 deer
(post #12792, reply #2 of 6)
What are the growing conditions this Rosemary is being subjected to? Powdery Mildew is a fungus that takes advantage of poor growing conditions, air circulation (or lack of) is a primary consideration. On outside plants I have had good success controlling PM on the Lilacs with a mixture of 1 teaspoon of baking soda in 1 quart of water sprayed every 5 days until all signs of the mildew is gone. Check the growing medium and find a different place for this plant where it will be happier.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
(post #12792, reply #3 of 6)
Hi,
It's a house plant. I'm thinking it must have had the mildew when I got it, just not obvious. I have grown rosemary before with no problem, & have no trouble with mildew on any of my (many!) house plants. Someone asked the active ingredient of the Safer's fungicide; it's sulfur, & it says it can be used up to the day before harvest. I'll try the baking soda & see if it works any better. Is there any reason not to do it every day?
(post #12792, reply #4 of 6)
Really none except it would be a waste of time and baking soda since it does take a day or two to work. I've had good results spraying just once most of the time with only an occasional need to spray more.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
West central Michigan along the lake shore
A sign of a good gardener is not a green thumb, rather it is brown knees.
(post #12792, reply #5 of 6)
Try sitting your rosemary outside for a while. Anywhere you can so it can get plenty of fresh air and some sunshine. If that doesn't help it I would just replace it. The spray you used may be "safe" but since herbs are about flavor, I would wash all that off (or let a good rainshower do it for me). I have had good luck with rosemary which I leave out in spring and summer and fall and bring in only in winter.
(post #12792, reply #6 of 6)
Putting it in the sun is good advice, if only I could follow it... We've been having so much rain around here that I should probably check myself for mildew!!