White patched on a marrow plant. what are they?

Question:my little sster has marrow plants growing in her green house but the have white spots on them can any one tell me what they are, and they harmful to the plant? and how do i get rid?

Answers:
Probably white powdery mildew. You can get a spray-on product called neem oil at upscale gardening centers to control it.

If they're little furry lumps, they're probably thrips. These are hard to get rid of, because the white furry stuff covers a hard scale that protects the thrip from pesticide sprays.

To remove thrips, you'll have to take the plant outside and spray it off with a strong mist (basically blast the thrips off the plants, being careful not to damage the plant). You can then use a standard spray insecticide to keep them from coming back.