Green Shiso Seeds - Kaori/Ao - Perilla frutescens var crispa

3, 4, 5, 6, 7, 8, 9, 10, 11

USDA Zones 3-11 - Green Shiso is grown as a heat-loving, fast-growing annual in all zones. It completes its life cycle in a single season and is killed by the first hard frost.

Best Performance - Achieved in Zones 5-9, where warm, sunny summers allow the plant to grow into a large, bushy herb perfect for regular harvesting.

Northern Zones (3-5) - To maximize the harvest season, it is best to start seeds indoors 4-6 weeks before the last frost date. Transplant outdoors only after the soil has warmed significantly, as the plants are tender.

Hot Climate Zones (9-11) - Shiso thrives in the heat. Plant directly in the garden in spring. In the most intense summer heat, the plant will benefit from a location that receives some afternoon shade and consistent moisture to prevent wilting and premature bolting (flowering).

Soil Temperature - Requires warm soil for germination, with an optimal range between 65-70 degrees F. Germination can be slow and erratic in cool soil.

Growing Season - Shiso grows quickly once established, allowing for the first harvest of leaves approximately 60-70 days after sowing. It will continue to produce until the first frost.

Learn more about USDA Hardiness Zones here

Seed Preparation (Recommended):
Shiso seeds can have a low and erratic germination rate due to natural dormancy. For best results, soak the seeds in water for 24 hours, then place the moist seeds in a plastic bag in the refrigerator for 5-7 days (cold stratification) before planting.

When to Sow:
Start seeds indoors 4-6 weeks before your last frost date. Or, direct sow outdoors after all danger of frost has passed and the soil is consistently warm (at least 65 degrees F).

Sowing and Germination:

Seed Depth: Shiso seeds require light to germinate. Press the seeds firmly onto the soil surface and cover with a scant 1/8 inch of soil or vermiculite, just enough to hold them in place.

Soil: Plant in rich, moist, and well-draining soil.

Germination: Keep the soil consistently moist until germination, which can take 7-21 days. Be patient, as sprouting can be uneven. Covering indoor seed trays with a plastic dome can help maintain humidity.

Transplanting and Spacing:

Hardening Off: If starting indoors, gradually acclimate seedlings to outdoor conditions over a week before transplanting.

Transplanting: Carefully transplant seedlings into the garden once they have two sets of true leaves.

Spacing: Space plants 10-12 inches apart to allow them to become bushy.

Ongoing Care:

Light: Shiso grows best in full sun to partial shade. Afternoon shade is highly beneficial in very hot climates.

Water: This plant requires consistent moisture and will wilt dramatically if the soil dries out. Water regularly, especially during hot, dry spells. Mulching can help retain soil moisture.

Fertilizing: Shiso is not a heavy feeder. Amending the soil with compost at planting time is usually sufficient.

Harvesting and Pruning: Begin harvesting leaves when the plant is 6-8 inches tall. Pinching the top growing tips will encourage a bushier plant and delay flowering, resulting in a longer harvest period of tender leaves. The flavor is best before the plant begins to produce flowers.