How to grow Shiso from seed. Shiso is a strongly flavoured member of the mint family. Its leaves have a tangy flavour of cumin, mint, nutmeg, and anise combined. In stature it resembles a large basil plant, and the cultivation is very similar to growing basil.
Perilla frutescens var. crispa
Season & Zone
Season: Warm season
Exposure: Full sun
Start indoors in early spring, a couple of weeks after the last frost date, or direct sow outdoors in late spring, once night time temperatures are steadily above 8°C (45°F).
If starting indoors, use equal parts sterilized seed starting mix to perlite. Mix well and add to seed trays with domes. Use bottom heat from a Seedling Heat Mat to maintain a soil temperature of 20°C (70°F). Seeds should germinate in 7 to 14 days. Be careful not to over-water, particularly once seeds have germinated, as the seedlings are prone to damping off. Remove the dome at germination, but maintain bottom heat until seedlings are large enough to pot on into larger containers.
Alternatively, direct sow outdoors into well-drained garden soil. Seeds should germinate in 14 to 20 days.
Shiso does best in full sun to partial shade, in fertile, well-drained soil. Allow transplants to become established, and then grow as you would basil — pinch growing tips regularly to produce bushier plants with more leaves. Water regularly, more so in hot weather. If growing in containers, mix equal parts potting soil and composted fine bark. Orchid bark works well.
Pick leaves as needed throughout the summer, and harvest the flowering tops in late summer. As autumn approaches, harvest the seeds for planting next spring.
Usual seed life: 1 year.