Yellow leaves on rhubarb

Asked August 5, 2020, 12:49 PM EDT

Hello, I have two rhubarb plants that are having some trouble. The leaves get yellow at the edges. The yellow then moves inward until the whole leaf is yellow instead of green. The yellow edges turn brown and dry as the discoloration spreads. The stalks lose some of their red color and get limp as well. The problem started shortly after i planted the first one last year. This year I have used an anti-bug and anti-fungal spray a few times. It seems to have helped a bit, but the plants are still losing leaves to this yellowing. There are still clearly bugs eating the leaves too. There is some shade from a nearby tree, but the plants are in full sun most of the day. They get water from an automatic system each morning. Any advice you can offer about how to help my rhubarb would be greatly appreciated!

Oakland County Michigan

2 Responses

I can’t tell what is wrong from your description, but I can give you some possibilities. First, rhubarb likes well drained soil. If it is getting watered every day it may be getting too much water. This can cause fungus growth, root rot and encourage slugs. Rhubarb also has a couple of diseases that cause problems. Ascochyta leaf spot causes yellow spots on leaves that turn brown and then leave holes in the leaves. This may look like insects are eating the leaves. Secondly, anthracnose stalk rot can affect rhubarb. It will appear as water-soaked areas on the leaves that get larger and cause the whole leaf to wilt. Both of these problems are best treated by collecting the infected leaves and removing them from the area. Also remove leaves after they freeze in the fall. To strengthen the rhubarb plants and make them more resistant to disease, fertilize them in the spring as soon as they begin to grow and again in mid summer.

Here are some bulletins with information on rhubarb problems.

https://plantvillage.psu.edu/topics/rhubarb/infos/diseases_and_pests_description_uses_propagation

https://hortnews.extension.iastate.edu/1995/6-30-1995/rhub.html

This is very helpful, thank you!