Can I eat my rhubarb?
NDSU Extension-Ward County introduces Kitty Torkelson who is the new horticulture assistant. She is available to answer horticulture questions now until early fall. Torkelson has been active in the Master Gardener program for 20 years and studied horticulture at the University of Minnesota before moving to North Dakota.
A sure sign of spring is rhubarb breaking through the ground. Rhubarb is one of the earliest perennial plants. It seems like every year we have a week or two of really nice temperatures, which allows the rhubarb plants to shoot up; then the temperature takes a dive with frost and freezing weather. Now the question is – ‘Can I eat my rhubarb?’
The answer is “Yes”, and “No.” Rhubarb is still safe to eat after frost if the leaves show no signs of wilt, are not blackened, and looks normal; you may harvest stalks as usual. However, if the leaves are limp, black, and wilted, they were damaged by frost. The frost forces oxalic acid, a toxin in the leaves, to go down into the petiole/stalks, making it not safe to eat. When consumed, the oxalic acid can crystallize and cause damage in the kidneys.
Remove and discard leaves that are wilted, limp, and blackened by pulling or cutting off at the base of the plant. The new growth will be safe to eat. If you are unsure and want to be safe remove all the stalks. Only do this one time during the spring growing season. As you begin normal harvest, always leave at least one-third of the stalks unharvested to ensure that the plant can consume enough nutrients to return next year.
An old wives’ tale is to stop pulling rhubarb mid-June and never after July 4th as it becomes toxic; this is false. As summer progresses, the stalks become woody and not as tasty, but they are not poisonous. Continually removing of the leaves and stalks will weaken the plant and reduce yield and quality of the next year’s crop. If you have a hankering for some rhubarb crisp or pie during mid-summer, I recommend pulling the smaller more tender stalks. Removing a few stalks should not cause any damage to next year’s crop.