How and when do I harvest edible bamboo shoots without harming the clump?

Harvest edible shoots when they are young and tender, usually when they have emerged about a foot or so above ground in the growing season, before they turn woody and bitter. Cut them at the base with a clean tool. The key to keeping the clump healthy is to not harvest all the shoots. Leave enough strong shoots each year to grow into mature culms, otherwise the clump weakens and pole production and future shoot yield both fall. A common practice is to take the early shoots for eating and leave the later, well placed ones to mature. So you can earn from shoots and still maintain the clump for poles if you harvest in moderation. After cutting, process or boil the shoots quickly since they harden and lose quality fast.