How to prune shiso (perilla)

From 15 cm tall onward; flower spike removal as soon as spikes appear (typically from midsummer). Pinch the growing tip just above the top pair of leaves every 1–2 weeks. When a flower spike emerges, pinch or cut it off at the base immediately. Harvest outer stems first to keep the centre growing. Deadheading also prevents the prolific self-seeding that makes shiso invasive in some regions.

Every 1–2 weeks throughout the growing season. Shiso needs regular pinching to stay productive. Pinch growing tips from about 15 cm tall to force branching and delay flowering — once it bolts, leaf quality drops sharply. Remove flower spikes the moment they appear to extend the harvest. As an annual, there is no long-term pruning framework; consistent harvesting and tip-pinching are the whole strategy.

Pinch the growing tip just above the top pair of leaves every 1–2 weeks. When a flower spike emerges, pinch or cut it off at the base immediately. Harvest outer stems first to keep the centre growing. Deadheading also prevents the prolific self-seeding that makes shiso invasive in some regions.