When to start herb seeds

This guide covers four common culinary herbs that behave quite differently from seed. University of Minnesota Extension groups herbs into cool-season types that tolerate cooler soil (parsley, chives, cilantro, dill, thyme, sage) and warm-season types that prefer soil near 60°F (basil, rosemary, lavender, oregano). Its general rule for herbs started indoors is 6 to 8 weeks under lights before transplanting, with transplanting after frost danger once the soil stays at or above 50°F.

Parsley: start early, or sow outdoors and wait

Parsley is slow. University of New Hampshire Extension gives it 9 to 10 weeks from seed to transplant and says it can go out 2 to 3 weeks before the last frost. With an average last frost of May 10, you would sow indoors February 8 to February 15 and set plants out April 19 to April 26. UMN's parsley guide uses a shorter 6 to 8 weeks before the last frost for indoor starts.

UMN says germination takes two to five weeks depending on seed freshness, and suggests soaking seed in warm water for up to 24 hours before planting. Iowa State Extension lists 70–75°F with 20 to 25 days to emergence. Harrington's data (published by Oregon State Extension) show about 29 days at 50°F and 14 days at 68°F, so warmth helps but parsley is never fast. Cover seed with about an eighth of an inch of soil.

UMN calls direct seeding the easiest way to start parsley: sow after the danger of spring frost, mark the row because emergence is slow, and thin to a final spacing of 10 to 12 inches. Seedlings look grass-like at first, with two narrow seed leaves.

Cilantro: direct sow in cool weather

Cilantro bolts (flowers and sets seed) quickly in warm, long days. Oregon State Extension recommends planting in early spring and again in late summer as temperatures cool, sowing small batches every few weeks, and avoiding peak summer heat. It sows 10 to 15 seeds per foot of row, covers them with half an inch of soil, and thins to 8 inches; seeds germinate at soil temperatures of 55–68°F, and mature plants tolerate light freezing. University of Wisconsin Extension suggests sowing at the same time you would plant lettuce in spring, every 2 to 3 weeks, and notes leaves can be harvested 45 to 80 days after sowing. Its long taproot makes transplanting difficult, so sow where it will grow.

Dill: direct sow after frost

UMN says dill does not transplant easily, so sow it directly where it will grow, starting after the danger of spring frost has passed. Plant seeds a quarter inch deep in rows two feet apart, thin to 10 to 12 inches when seedlings are two inches tall, and sow again every two to three weeks through midsummer for several harvests. Choose a sunny spot sheltered from strong wind, because the tall, hollow stems blow over. Iowa State lists dill as needing light to germinate (65–70°F, 7 to 14 days), so don't bury it deeply.

Chives: divisions are easiest

Chives are a hardy perennial in the onion family. UMN says the easiest and most successful way to grow them is planting rooted clumps in spring after frost danger, spacing them 6 to 12 inches apart, and dividing established plants every three to four years. You can start chives from seed too, and once established a clump comes back each year.

Common mistakes

• Giving up on parsley. Two to five weeks to sprout is normal.
• Transplanting dill and cilantro. Both are best sown in place.
• Sowing cilantro in midsummer. It bolts before producing many leaves.
• Overfeeding. UMN notes rich soils promote lush growth with less flavor and aroma.