If the seedleaves (cotyledons) come up damaged and brown, bean seeds have been too moist in the soil. This happens frequently with white seeded beans. If the actual leaves are damaged I suspect slug and snail damage after emergence.

My beans (scarlet runner beans, purple beans, lima beans) came up great but the leaves are full of holes now! Is this slug & snail damage? Should I get some Sluggo?

What kind of holes? Little ones like made by a shotgun all over the leaf or big chunks eaten out of the edges of the leaves? The former may be flea beetles, the latter may be slugs.

Jim

Slugs unfortunately often go for the growing tip along with the leaves of seedlings. They just leave stumps which will no longer grow. A set of stumps and slimy trails definitely indicates slugs.

A few holes in the leaves are not usually fatal and they can have several reasons. A certain amount of damage does happen always with newly emerged, soft leaves. Once the leaves get older and tougher, the problem generally resolves itself quickly. As Jim said, fleabeetles or birds (pigeons especially) like to take a bite out of leaves as do some caterpillars. Strong winds can harm leaves, even scorching from water droplets in hot sunshine. These type of damage problems can usually be overcome by the plants. Unless your beans are actually decimated by them, they will grow out of it.

If the leaves were damaged prior to emergence, the most likely cause is a hard-packed soil, or having been planted too deeply. Sometimes the stem can actually snap, leaving the whole growing tip broken off beneath the soil. If this is the case, you should be able to gently dig in the soil next to the seedling, and find the missing leaves.

I have often wondered if earthworms sometimes play a role in this as well, by trying to drag the still-living vegetation into their burrows.

The cure is most often to plant the seed less deeply, plant in groups, or add organic material to improve tilth. My own soil is a silt/clay mix, that after heavy rains, bakes to a hard crust. When I plant beans, I plant them in groups, which together can break through the crust. I also watch for the first signs of emergence, then gently break the soil surface around the seeds, to help them break through.

If the leaves were damaged immediately after emergence, I would suspect either cutworms, slugs, or birds. In the case of severe damage (loss of many leaves, or of whole plants) rabbits or squirrels could be responsible.

For slugs, any of several iron-based commercial slug baits will kill most of them. For cutworms, dig around the base of several plants, looking for the caterpillars. I once lived in an area where they were common, and they can be very destructive. Birds can be difficult to discourage, so if they prove to be the culprits, some type of netting above the seedlings might be necessary, until the seedlings have grown too large to be attractive.