Benton County Master Gardener Problem Diagnosis Scenario #17
(Rhubarb problems)
Problem
My rhubarb plants are not doing well. What can I do to get a good crop?
Description
My rhubarb plants are small and don't produce useable fruit. The stalks are skinny, and
there are not many of them.
Questions and Answers
Question: How many plants do you have?
Answer: Hard to tell as they are all bumped up against each other.
Question: How old are your plants?
Answer: At least seven years old; they were there when we moved in. We have never had a
good crop.
Question: Do you fertilize?
Answer: No, I heard rhubarb doesn’t need any.
Question: How do you water?
Answer: Occasionally, irregularly.
Reference(s)
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/18475/ec797.pdf
Bradley, Fern Marshall. Rodale’s Vegetable Garden Problems. 2007: Rodale. Pp. 342345.
Diagnosis
Over-crowded crown: The crown has become overgrown and crowded. Water
regularly and provide nutrition.
Recommendations
Cultural:
1. Fertilize in spring as plants begin to grow. See OSU extension pamphlet for
amount.
2. Apply compost or well-rotted manure in the fall after the leaves dies back.
3. Water regularly and well. Cultivate out weeds in the spring and keep them out
from around base of plants. Remove any flower stalks that appear as soon as
possible.
4. The crown needs to be divided every four to five years. Leave 1/3 of the original
plant. Trim back to four or five buds. Can start new plants with divisions as long
as they have at least one active bud. Plant at least 36 inches away from mother
plant.
5. Check soil pH. Rhubarb tolerates pH down to 5.0 but produces best in pH 6.06.8. Apply lime in the fall to adjust pH if soil is too acid.
#17
Spindly, less than pencil-sized stalks
Nice harvest
Now that is a healthy rhubarb plant leaf!