Growing Herbs Year-Round: Outdoor Beds, Windowsills, and Grow Lights

Herbs split into two rough groups for year-round growing: perennials that can overwinter outdoors with protection, and tender annuals or tropicals that need to come inside or be restarted from seed each year. Treating them the same way is the most common reason indoor herb pots die by January.

Perennial herbs that survive outdoors with mulch

• Thyme, sage, oregano, and chives tolerate freezing temperatures once established and mostly need a mulch layer over the crown for extra protection.
• Rosemary is borderline in colder climates and often needs to come indoors or into an unheated garage over winter.
• Mint spreads aggressively and survives outdoors almost everywhere it is planted — the challenge with mint is containment, not survival.

Herbs that must move indoors or restart from seed

Why windowsills usually fail herbs in winter

Winter daylight through glass is both shorter and weaker than the same window in summer, and most kitchen windowsills fall well short of the 6+ hours of strong light most culinary herbs want. Plants respond by stretching, going pale, and producing thin, weak-flavoured leaves rather than dying outright, which makes the problem easy to miss until the harvest disappoints.

Bringing outdoor pots inside for winter

1. Inspect for pests and rinse foliage before bringing pots indoors, since indoor conditions let infestations explode unchecked.
2. Move plants indoors before the first frost, not after — a sudden hard frost can damage even cold-tolerant herbs in pots, which are more exposed than the same plant in ground.
3. Reduce watering frequency indoors, since growth slows in lower light and overwatering becomes the main risk.
4. Expect a period of leaf drop as the plant adjusts to lower indoor light; this is normal, not necessarily a sign of a dying plant.