The white mold on the leaves is called powdery mildew, and it is common on the crops you've listed. However, stop watering every day--that's unnecessary and is probably causing the rotting problem. Water once per week--about an inch of water each time. The garden needs to be in full sun (minimum of 6 hours direct sun), with good air circulation, and the soil should drain well. I would also not feed more often than every two weeks. You can try using a preventive anti-fungal spray made for food crops (such as this one: http://www.gardensalive.com/product.asp?pn=2325) , but it's most effective if you use it repeatedly over the growing season.