The edges are turning yellow and the growth (length) of the stalks seems to be shorter than usual. These plants are over 30 years old and have been excellent producers. I have divided them 3 times with success. I am also having aphids (I believe) eating my sweet potato vine, caladiums, and such this year in greater numbers.
What Is Eating the Rhubarb Leaves From the Edges?
Certified GKH Gardening Expert
There are numerous pests and caterpillars that may be dining on your Rhubarb.
You can treat the plants with Neem Oil, including your other plants that are having trouble with Aphids.
Neem Oil is organic and safe for people, pets and bees.
Here is a link with more information