Q.young bean plant leaves are green but crumbling
I live in Tempe, AZ and just started a potted garden. I planted some heirloom green beans that sprouted great, got to 6-7,” and now the main leaves are crumbling at the edges, and of the 12 sprouts only 6 have survived. We keep the soil moist, and they are out of direct sun. Am I over watering? Over feeding? Or is it just too hot?
Your Green Beans do need full sun and well draining soil.
The soil should dry just slightly between waterings, you don't want the soil to stay soggy.
Make sure the pot has a good drainage hole, so excess water can drain from the soil.
When watering your beans, take care not to have the water splash onto the plants leaves. This can lead to fungal infections.
Here is an article with more information.