Famine, Drought and Pestilence

Ok, it's just powdery mildew, but it is attacking all of my Blue Lake Bush Bean plants.

Bean plants have white powdery looking spots
the likely cause of which is powdery mildew

Once, I saw the spots, I knew I had to do some reserach. Powdery mildew is a fungal disease. The spores causing this problem are in the Erysiphaceae family. They exist in dirt and debris and are spread in the air and are not easy to avoid, but spacing your plants well and not allowing them to be too damp can reduce the chances the spores will find your plants appealing.

The disease is not fatal to affected plants, but because the spores causing it take nutrients away from them, it can affect the affected plants' general health. Large and large amounts of mildew spots on the plant can reduce the amount of chlorophyll and thereby interfere with photosynthesis.

Already, some of my beans appear to be thinner and drying out (ok, it would help if I didn't let the soil get dried out too).

I learned from my reading that there are many different types of powdery mildew that affect different plants. So, my bean powdery mildew is not necessarily a threat to my other plants. I also learned that I can control the problem by thinning out my plants, removing affected areas. I should also refrain from fertilizing until the problem is solved and water the plant at the base, not from above.

There are several commercial sprays for powdery mildew on the market, potassium bicarbonate or sulfur based products. Here's one home remedy for powdery mildew: 1 tablespoon of baking soda and ½ teaspoon of liquid soap to 1 gallon of water. This mixture can burn the leaves, so it should not be used in full sun. Another home remedy is purified water and neem oil.

I think my problem is that I overcrowded my container. It's also a container that's been inside, not getting the benefits of wind and fresh air. I'm going to prune off the affected areas, thin my plants and take them outside. We'll see what happens.