How to Grow Shiso (Perilla): Planting, Care & Harvest

Shiso (Perilla frutescens) is the boldly flavored Japanese herb behind sushi garnishes, umeboshi plums, Korean kkaennip wraps, and Vietnamese herb plates. A member of the mint family, it grows fast and easy in summer heat, producing big, ruffled, aromatic leaves in vivid green or deep burgundy-purple with a flavor that lands somewhere between basil, mint, cinnamon, and anise — unlike anything else in the garden. Treat it as a warm-season annual, give it sun and steady moisture, and one or two plants will keep a kitchen in fresh leaves all summer. This guide covers sowing, spacing, harvesting, the green-versus-purple types, culinary use, and managing its prodigious self-seeding.

Green vs. Red Shiso

Two main forms show up in seed catalogs, and they are used differently. Green shiso (aojiso, P. frutescens var. crispa) has bright green ruffled leaves with a fresh, bright herbal flavor — this is the leaf served with sashimi, shredded into salads and noodles, used as a wrap, and battered for tempura. Red or purple shiso (akajiso) has deep burgundy, sometimes bicolored leaves and a stronger, more medicinal, cinnamon-clove edge; it is used mainly to color and flavor umeboshi (pickled plums), pickled ginger, and shiso juice, and to add dramatic dark foliage to the garden. There is also Korean perilla (kkaennip), a related plant with larger, flatter, nutty leaves used for wraps and kimchi.

Both grow identically; choose by how you cook. Many gardeners grow a plant or two of each. The purple type doubles as an ornamental and looks at home in a flower border as well as the herb bed.

Where and When to Plant

Shiso is a heat-lover with no frost tolerance, so treat it strictly as a warm-season annual. It grows best in full sun to part shade — in hot-summer regions a little afternoon shade keeps the leaves tender and slows bolting, while in cool climates full sun gives the strongest growth. It reaches 18–36 inches tall and does well in the ground, in raised beds, or in a 1–2 gallon container, making it a natural fit for a sunny patio or balcony herb pot.

Soil should be rich, moist, and well-drained, with a pH around 5.5–6.5. Unlike the lean-soil perennials, shiso is a leafy annual that responds to fertility — work compost into the bed before planting. Wait to plant until all danger of frost has passed and the soil has warmed to at least 65°F; shiso sulks and germinates poorly in cold soil. It thrives in the same warm, moist conditions that suit basil, and is a good companion herb in a summer kitchen garden.

Sowing and Spacing

From Seed

Shiso seed can be slow and finicky, so a few details matter. It needs both light and warmth to germinate: surface-sow and barely press it in, do not bury it, and keep the medium at 65–70°F. Fresh seed germinates better than old, and many growers cold-stratify the seed in a damp paper towel in the fridge for one to two weeks first to break dormancy. Start indoors 6–8 weeks before your last frost, or direct-sow once the soil is reliably warm. Germination takes 1–3 weeks; be patient. Once up, seedlings grow quickly.

Transplanting and Spacing

Harden off indoor-started seedlings and transplant after the last frost when nights stay above 50°F. Space plants 10–12 inches apart, or grow one plant per gallon-plus container. Water in well. To get full, leafy plants rather than tall, sparse ones, pinch out the growing tip when seedlings reach 6 inches; this forces side branches and multiplies your leaf harvest, exactly as you would pinch basil.

Watering, Feeding, and Routine Care

As a leafy summer annual, shiso wants steady moisture for the most tender, flavorful leaves. Keep the soil consistently moist but not waterlogged — water when the top inch dries, more often for container plants and in heat. Drought-stressed plants get tough, bitter leaves and bolt early. A layer of mulch helps hold soil moisture and keeps the bed even. Feed lightly every few weeks with a balanced or slightly nitrogen-leaning fertilizer to keep leaf production going; over-feeding can dull the flavor, so a moderate hand is best.

The single most important ongoing job is pinching and harvesting often. Regularly removing the growing tips and any flower buds keeps the plant in vegetative, leaf-making mode and delays the late-summer bolt that turns leaves bitter and signals the end of the season. Because shiso likes the same rich, moist, warm conditions as other tender annual herbs, it slots easily into a productive container or raised-bed herb planting.

Harvesting and Culinary Use

Start harvesting once a plant has several sets of true leaves and is growing strongly, usually 6–8 weeks from sowing. Pick individual leaves as needed, taking from the top to encourage branching, or harvest whole stem tips. As with basil, frequent picking keeps the plant productive and bushy. Use the leaves fresh — shiso wilts fast and does not store long; refrigerate stems in a glass of water like cut flowers, or wrap leaves in a damp towel for a few days.

In the kitchen, green shiso is a fresh-leaf herb: lay it under sashimi, shred it over rice and cold noodles, fold it into salads, wrap grilled meat in it, or batter and fry whole leaves as tempura. Red shiso is mostly a pickling and coloring herb — it gives umeboshi and pickled ginger their pink-red hue and tart, perfuming flavor, and is the base for the summer drink shiso juice. The seeds and flower spikes (hojiso) are edible too, used as a garnish and lightly pickled. Because the leaves do not dry well, the herb is best enjoyed in season; freeze leaves in oil or make a shiso pesto to extend the harvest.

Reseeding and Managing Spread

Here is the warning every shiso grower needs: it self-seeds prolifically and, in mild climates, has naturalized and become weedy in parts of the U.S. Left to flower in late summer, a single plant scatters seed that sprouts in dense mats the following spring. To enjoy it without losing the bed, cut off the flower spikes as they form — this both prolongs your leaf harvest and prevents seeding. If you want a few volunteers for next year, let just one or two spikes mature and pull the rest of the seedlings as they appear in spring; they transplant easily and are simple to weed out where unwanted. The reseeding habit puts shiso in the same camp as other vigorous self-sowers covered in our guide to growing herbs and managing reseeding.

Pests, Problems, and Season’s End

Shiso is largely pest-free; its strong aromatic oils repel many insects and deter deer and rabbits, which is why it is sometimes planted as a companion to protect other crops. Occasional issues include flea beetles peppering young leaves with tiny holes, aphids and spider mites in hot dry spells (rinse off with water), and slugs on seedlings. Good air circulation prevents the rare leaf-spot or rot in humid weather. As days shorten in late summer the plant bolts, flowers, and the leaves turn bitter — this is normal. Harvest heavily before then, and the first frost will end the season. In a balcony or patio garden, the same warm-season, rich-soil container approach used for other tender herbs applies to shiso.