Container pole bean leaves are looking rough.

Question

I have a Kentucky pole bean plant in a 5 gallow container and it started out growing well and now, it is about 3 feet tall with brownish colored leaves and the beans are growing very slowing and shaped irregularly, like short and wide!

I water it regularly and use liquid fertilizer (8-16-8) about every 10 days. It is in direct sun. I live in Maryland and our summers are very warm and humid.

What am I doing wrong? What does this plant need? Any suggestions would be greatly appreciated.

Answer 1

One thing that can cause damage to leaves like you describe is thrips, a tiny insect that rasps the leaves to get nutrients. You might try a light dose of horticultural oil to suffocate them. Look for something called "light summer oil" or "dormant oil" at the garden store. Just be sure to read the label and make sure it can be applied to growing plants, because dormant oil at full strength will suffocate your plants as well as the insects.

Thrips are a real problem where I live but I don't know if you have them in Maryland. You might also take a leaf or two to the local nursery and ask someone knowledgeable. Or check with your cooperative extension agent (I've put the link here).

When it gets very hot beans will have problems fruiting. The high temperatures will cause incomplete pollination and the bean pods may not completely fill out or grow long, they will be short and misshapen. This might be another problem with your bean pods besides the thrips. I notice it in my garden when it starts getting over 90F regularly. I believe that pole beans can keep growing through this phase and start fruiting later (I only grow bush beans though, so I won't swear to it).

Hope this helps.