How Long Can You Continue to Cut Rhubarb in the Spring?

Savoring a Springtime Treat

• Rhubarb is generally harvested for about eight to 10 weeks beginning in March or April, as the plant resumes growth when temperatures rise above 40 degrees Fahrenheit. Stop harvesting rhubarb when the plant begins to produce slender leaf stalks, a sign of low food reserves. Harvest generally lasts no later than mid-June to early July. If you have a late-season craving for rhubarb, a small, later harvest that removes just a few stalks is acceptable and has little impact on a healthy plant's vigor the following year.

Why Stop Harvesting?

• In the spring, rhubarb leaf stalks and leaves grow using reserves built up in the rhubarb's crown. For enough energy reserves to accumulate in the rhubarb crown to support leaf production the following spring, sufficient leaves must be left intact on the plant for a long enough period. Stalk quality also decreases later in the season. Stalks do not become poisonous but develop a woody or tough texture. Rhubarb leaves, however, are toxic and should never be eaten.

Those Pesky Flower Stalks

• Increasingly warm temperatures stimulate the production of flower stalks on rhubarb plants, which depletes the plants' energy reserves. Unless you find the rhubarb flower stalks particularly attractive, cut off any flower stalks, which emerge from the center of a rhubarb clump and look different from the surrounding leaf stalks, as soon as you notice them. Because flower stalks tend to form earlier if a plant is drought stressed or lacks nutrients, addressing these factors can discourage flowering. Water rhubarb plants weekly during dry spells, and spread 1/2 cup of a complete, slow-release fertilizer with a 10-10-10 or similar formula around the base of the plant in early spring.

Divide and Conquer

• When harvesting rhubarb, grasp each stalk near its base, twist and pull to collect the stalk and then cut the leaf off of each stalk, rather than using a knife or scissors to remove the stalk from the plant, to reduce the potential for disease spread. If the rhubarb stalks are soft following a freeze, do not harvest these cold-damaged stalks for consumption. Rhubarb plants benefit from a division in early spring every five to 10 years.