When to harvest pennyroyal

Pick young and tender, while the pod snaps cleanly rather than bending. Pennyroyal produces more the more you pick. Once the plant sets mature seed it reads that as its job done and slows or stops, so harvesting young and often is the whole trick — a plant picked every couple of days can crop for weeks longer than one left to fill out.

Hold the stem with one hand and pick with the other, or snip with scissors. Pulling one-handed tears the brittle stems and can uproot the whole plant.

Best eaten within a couple of days — sugars turn starchy fast. For longer keeping, blanch briefly and freeze on the day of picking.

Letting pods fatten up on the plant. A few mature pods tell pennyroyal to stop flowering, and the crop ends early.