Can You Grow Rhubarb in a Pot or Container?

Rhubarb can be grown in a container, but it is worth being clear about what this involves and what the realistic expectations are. Rhubarb is a large, vigorous perennial with a substantial root system — it is not a natural container plant. Given the right conditions (large enough container, regular feeding and watering) it is possible to produce a reasonable harvest from a pot, but the yield will always be less than from the same variety in open ground, and the plant will need more careful attention to avoid drying out or becoming pot-bound.

Minimum container size

The pot must be large — a minimum of 50cm diameter and 40cm depth. Smaller pots will be colonised by roots within one growing season and produce small, thin stalks. Half-barrels (approximately 60cm diameter) are ideal and allow a plant to remain productive for three to four years before dividing and repotting. Use a loam-based compost (such as John Innes No. 3) rather than multi-purpose compost, which compacts and degrades too quickly in large containers.

Feeding and watering in containers

Container-grown rhubarb requires significantly more attention to feeding and watering than garden-grown plants. Water regularly — pots dry out much faster than open ground. Feed monthly throughout the growing season with a balanced liquid fertiliser. In late winter, top-dress the surface with well-rotted compost or a slow-release fertiliser to replenish nutrients for the coming growing season.

Cold requirement

Rhubarb requires a period of cold (below 5°C) to break dormancy and produce vigorous spring growth. Container plants on sheltered patios may not receive sufficient chilling if temperatures stay mild all winter. Leave containers outdoors through winter in an exposed position rather than in a heated greenhouse or sheltered corner.