Shiso Seeds – Perilla frutescens

Shiso germination typically occurs somewhere between 7 and 21 days under good conditions, though this range can shift depending on soil temperature, moisture, and seed freshness. Warmer soil closer to 70 degrees Fahrenheit tends to bring sprouts along faster, while cooler or inconsistent conditions may stretch the timeline. Pre-soaking seeds for 24 hours before planting often helps move things along.

Shiso does quite well in containers, provided the pot is large enough, aim for at least a 12-inch diameter container with drainage holes to give roots room to spread. Use a quality potting mix with some compost blended in, and keep in mind that container plants dry out faster than in-ground ones, so check moisture more frequently. A sunny balcony or patio spot works well for a thriving potted shiso plant.

Perilla frutescens is considered toxic to cats and dogs, and in larger quantities it can cause serious digestive distress and other symptoms in pets. If you have animals that roam your garden freely, it is worth placing shiso where they cannot easily access or chew on the plants. When in doubt, consult your veterinarian about specific risks for your pet.

Shiso has a complex, layered flavor that is genuinely unlike any single herb in Western cooking, carrying elements of basil, mint, anise, clove, and something faintly citrusy all at once. Green shiso herb tends to be slightly brighter and more delicate, while the red or purple variety often reads as more robust and slightly more savory. People who enjoy it tend to reach for it constantly once they start growing it.

The most reliable approach is to remove flower spikes before seeds have a chance to fully mature and drop, which also keeps the plant producing better foliage through the season. At the end of the season, cut plants back before they fully dry out and shed seed across your beds. If you enjoy having volunteers return each year, you can selectively allow one or two plants to go to seed in a contained spot.

A good rule of thumb is to start shiso seeds indoors about 4 to 6 weeks before your average last frost date, which gives seedlings time to establish before transplanting into warm outdoor soil. Because shiso dislikes cold roots, hold off on transplanting until nighttime temperatures are reliably above 50 degrees Fahrenheit. Starting too early indoors can lead to leggy, rootbound seedlings that struggle at transplant time.

Green shiso herb and purple perilla seeds both come from the same species, Perilla frutescens, but they are distinct varieties with different appearances and slightly different culinary uses. Green shiso is most commonly used fresh as a wrap for sashimi, in salads, or chopped into noodle dishes, while red or purple shiso is the traditional colorant for pickled umeboshi plums and is also used in teas and Korean kimchi. Flavor-wise, both share that signature complex aroma, though many cooks find the green variety a touch more subtle.