[Broadhaven]

How do I treat my Monarda that has powdery mildew on it. It is looking lovely apart from the leaves.

[mumofstig]

Try spraying with either milk and water or bicarb and water. Works on cu and pumpkin
Try on a little bit first just in case the plant has a strange reaction...  i suppose you never know

link for spray

[Trillium]

2 kinds of powdery mildew happen, one from extreme dryness at the roots which stresses the whole plant, the other from damp plants growing too closely. Which is yours?

[Broadhaven]

Hi Trillium

To be honest I am not sure which category the plants would fall into. But I have about 5 plants each about 15in apart when planted earlier in the spring. I only seem to have mildew on 2 of the plants. These are also the only ones in flower at the moment.

[Trillium]

With only 5 plants, then its not overcrowding. So, I assume its the dryness type of mildew. If you check at soil level and the ground is quite hard, then they need some water. It won't get rid of the existing mildew but it should prevent the others developing it. Even drought tolerant plants can get too dry and show signs of suffering (mildew). Come fall, cut down the affected plants and either bin or burn them.