what's good to prevent mildew, that white stuff on rose bushes?

Answer 1

Roses are quite subject to Powdery mildew , especially this time of year when the evening temps drop. Several things you can do.
Most important is to keep the foliage dry at night, so when you water or spray do it early enough in the day so the plant will be dry by night time. Keep good air circulation around the Base of the rose bush and all fallen debris removed.
Prune off all infected parts and spray every 2-3 days through out the rest of the season with the recipe below.
2tbs. of baking powder
2 tbs cooking oil
a few drops of liquid dish soap in a spray bottle of water.
Shake well!!
spray all parts of plants.
There are many fungicides on the market for mildew but I have found this organic one to do just as great of job if not better.
God Bless
Grandma

Answer 2

LISTEN TO YOUR GRANDMA...Seriously, the lady calling herself grandma is so right on the money. I work in a garden center as the Integrated Pest Management consultant, and that is exactly what I world have told a customer! Best Answer...Grandma

Answer 3

mix a little liquid dish soap in a spray bottle and spray it on, it'll get rid of aphids too, I've also used tobacco mixed with water it does the same thing

Answer 4

spritz with diluted cider vinegar water