To know when rhubarb is ready to harvest, focus primarily on the size and firmness of the stalks rather than their color:
- Stalk Length: Harvest rhubarb stalks when they reach about 10 to 12 inches (25 to 30 cm) long. At this size, the plant is established enough to tolerate picking
- Stalk Thickness and Texture: The stalks should be thick, firm, and crisp, not thin, spindly, or woody. They should bend slightly without snapping
- Color: While many rhubarb stalks are red, color alone is not a reliable indicator of readiness. Both green and red stalks can be ripe if they meet the size and texture criteria
- Taste Test: A ripe stalk will have a slightly tart flavor with a touch of sweetness and minimal stringiness. Overly sour or bitter stalks may need more time to mature
- Harvest Timing: Rhubarb is generally ready to harvest in spring through early summer (April to June), with the best flavor early in the season. Avoid harvesting more than one-third of the plant at a time to keep it healthy
- Harvest Method: It is best to pull the stalks gently from the base or cut them close to the crown, avoiding damage to the plant. Remove and discard the leaves, as they are toxic
In summary, wait until rhubarb stalks are about 10–12 inches long, firm, and crisp, then harvest selectively during spring and early summer for the best flavor and plant health
