Rhubarb requires sufficient winter chill to break dormancy in the spring. Some varieties, especially the red ones, may not receive enough winter chill in Santa Clara County, depending on the microclimate. The mostly green variety Victoria seems to be reliably productive here.
WARNING: Do not eat rhubarb leaves! They contain toxic amounts of oxalates. Only the stalks are safe for eating.
When to plant: Plant dormant crowns in late winter–spring.
Harvest window: Spring into early summer
Fertilization: Apply nitrogen in the spring.
Annual care overview:
- When to harvest
- First year: No harvesting. Plants need energy to get established.
- Second year: A few stalks may be harvested if growth is vigorous.
- Third year onward: Harvest freely in the spring once plants are established, but never more than 50% of the stalks.
- Stop harvesting when the weather gets hot and the stalks get thinner, so plants can replenish their roots
- Harvest stalks by pulling and twisting off from the base. Cutting can leave a stub that may rot.
- If a bloom appears, break it off (unless desired for ornamental purposes).
- Keep plants well watered and well mulched.
Rhubarb Production in California (oriented to commercial production, but has some useful information)
Rhubarb (Sonoma Country Master Gardener Program)
Some Recommended Varieties for Santa Clara County*
Victoria, Glaskins Perpetual
* Many other varieties may also do well here in Santa Clara County. This list is based on UC Master Gardener trials, taste tests, and feedback from local growers.