Do not harvest asparagus spears the first year All the plants to develop a strong root system. Harvest mid to late spring in the third year after planting. After the third year, the harvest will extend 6-10 weeks. Harvest when spears are ¼-¾” (6-19 mm) in diameter and about 5-8” (13-20 cm) long by snapping off shoots at the base. Harvest before the stems toughen and the scales at the tips begin to open.
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