Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Rhubarb — Growing reference
| Scientific name | Rheum x hybridum |
|---|---|
| Seed germination (days) | 14–21 |
| Soil temperature for germination (°C) | 10–21.1 |
| First harvest or flowering (days) | 365–730 |
| Measured from | Transplant |
| Plant spacing (cm) | 91.4–121.9 |
| Mature height (cm) | 61–121.9 |
| Mature spread (cm) | 91.4–121.9 |
| USDA hardiness zones | 3–8 |
| Light | Full sun |
| Water | Moderate |
| Sowing method | Division |
Growing directions
Plant root divisions 3–4 in deep in deeply dug, compost-enriched soil, setting buds just at the soil surface. Do not harvest any stalks in the first year, and take only a few in year two so the crown can establish a deep root system. From year three onward, harvest stalks when they are 12–18 in long and 3/4 in thick by pulling and twisting at the base; remove any flower stalks that appear immediately to prevent weakening the crown. Note that only the stalks are edible—the leaves contain high concentrations of oxalic acid and are toxic.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0