Here are a couple of inexpensive home remedies for some garden problems:
Basil Tea bug killer:
If you're having a problem with bugs in the garden, crush a handfull of fresh basil leaves and put them in a jar of water. Sit the jar outside in the sun for 1-2 days to steep, then strain the water out into a spray bottle and apply to plants to get rid of bugs.
Cures for Powdery Mildew (white mold on your plants):
Mix one part milk with three parts water in a spray bottle and apply to plants.
-or-
Mix 1 tbs baking soda, 2.5 tbs vegetable oil, 4-5 drops of liquid soap and one gallon of water. Add mixture to a spray bottle and apply to plants. Make sure to continuously shake the mixture to ensure uniform consistency.