The Chinese Grower and Rootwise Garden
20 minutes
Spring-Sown Spinach Bolts as Days Lengthen Past About 14 Hours
Spinach is a long-day plant: above roughly 12–14 h of daylight, from late April in London (52° N), it bolts within weeks. Sow early, pick young, choose bolt-resistant varieties, or switch to chard or perpetual spinach.