Stems can be picked from the early cultivars from March to April. Do not harvest in the first season after planting and harvest only lightly in the second season to avoid weakening the crowns. From seedling plants, harvest in the second season after planting or in the first season after division.
Stems should be pulled rather than cut to prevent rotting of the remaining stump. Pull stems when they are between 23-30cm (9-12in) long, holding them at the base and pulling gently outwards. Take no more than half the total stems at any one time.
The last harvest is usually in late summer, around July or August, though growth may have stopped before this if the weather is very hot. Concern is sometimes expressed over the concentrations of oxalic acid building up as the season progresses. However, this build-up is mostly in the leaves which are not eaten and the amount in the stems is not sufficient to have a toxic effect.