Shiso is easy to recognize once you brush a leaf: the aroma is bold, green, and unlike the familiar kitchen herbs. Getting it started is less immediate. Its seeds can germinate unevenly, so a warm, carefully tended seedbed is more useful than sowing a deep row and hoping for the best.
Sow Shallow and Keep Moist
Start seeds indoors in warmth or sow outdoors once the soil has warmed. Press them onto the surface or cover them very lightly, since deep planting can make emergence harder. Keep the growing medium evenly moist, not waterlogged, while you wait.
Soaking seeds overnight before sowing may help them take up water, though it does not make germination perfectly uniform. Give the seed tray time, and avoid letting the surface dry out between checks. Once seedlings appear, provide strong light so they grow sturdy rather than stretched.
Choose a Site for Summer
Move plants outdoors after the danger of frost has passed and conditions are reliably warm. Shiso grows well in sun with regular moisture, while a little afternoon shade can help in hot, exposed gardens. A spot near the kitchen makes frequent leaf harvest convenient.
Give plants enough space for air to move through their foliage, and water during dry spells. Pinching the growing tips encourages branching and gives you more leaves to harvest. If the plant starts sending up flower stalks, keep picking leaves to extend the useful leafy growth.
Harvest Before It Runs to Seed
Pick individual leaves as the plant fills out, taking a few from each stem rather than stripping one branch bare. The fresh leaves are the main harvest, and their vivid aroma is best appreciated soon after picking. Regular use also gives you a reason to notice when flowering begins.
Shiso can self-seed where growing conditions suit it, so remove spent flower heads if you do not want volunteers. For a dependable patch next season, save seed only from healthy plants and store it dry; otherwise, start fresh and give the next sowing the same warm, shallow beginning.