I have squash seedlings that are maybe 8-10" tall with 3-4 leaves and they seem to have powdery mildew. I've had it before late in the season, but never in the beginning. Should I be concerned since it's affecting smaller plants?
Yes be concerned and alarmed but not paranoid for I will give you my advise on a solution that will take a tiny bit of effort and repetition mix a powdered milk solution with water and spray upper and lower leaves and soil and sprinkle powdered milk all over the surface of the soil after you water them with a 9 to one ration with water and milk then next couple of days spray with baking soda and water mix the next couple days spray with 1 tablespoon vinegar mix with 1 gallon water, take a blender and put in almost hot water and puree many garlic cloves then strain thru regular strainer to catch most of the pulp into a finer yogurt type strainer now you have your concentrate that you can store in frig up to 3 to 4 weeks use alone diluted and spray plants or mix in combination with all the above if you wish alternate with the baking soda then next 2 or 3 days apple cider vinegar once in awhile top and bottom of leaves and the soil surface stay up on all these suggestions for awhile even on near by plants cause this has spread and will come back do this for about two weeks then lay back and do every 2 weeks and you should have total success with you hard earned harvest(P.S. very lightly sprinkle soil then leave with cinnamon important lightly on leaves heavier on soil,plus cinnamon keeps ants away