When to Bring Basil and Tender Herbs Indoors
Move basil before nights linger near 50F. Pot tender herbs, take cuttings, and keep a bright windowsill winter garden going after frost.
Published by ThriveThyme
basil herbs frost indoors winter
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When to Bring Basil and Tender Herbs Indoors
Basil is a tender annual. A hard frost ends outdoor plants. Penn State Extension notes basil struggles when temperatures drop below about 50F, so do not wait for the first 32F night if you want living plants indoors.
Confirm your timing with first frost date and the Frost Harvest Desk. Pair this guide with how to bring rosemary indoors for winter for woody herbs that hate wet cold more than a short chill.
Trigger Temperatures
- Basil (sweet, Thai, purple): Pot up or take cuttings when forecast nights approach the low 50s F. Cover helps for one light chill. It will not save plants through a freeze.
- Marjoram and other tender perennials: Move before hard frost in zones colder than about 9.
- Cilantro, dill, and chervil: Cool-season annuals. Harvest what you can, or pot a plant for a short indoor run. They are not long-lived houseplants.
- Hardy perennials (sage, thyme, oregano, chives, mint, lemon balm, tarragon): Usually stay outdoors. See which herbs survive winter by zone.
How To Pot Tender Herbs
1. Choose compact, healthy plants. Avoid plants with heavy pest pressure or disease. 2. Dig a root ball that fits a pot with a drainage hole. Use a free-draining potting mix, not heavy garden soil. 3. Trim a little top growth so roots can catch up. For basil, you can also root 4 inch tip cuttings in water or moist mix. 4. Hose or wipe leaves and stems. Isolate new indoor plants for several days. 5. Place basil in the brightest warm window you have. Penn State Extension suggests daytime rooms about 65 to 70F and nights about 55 to 60F for most indoor herbs, and warns against cold windowsills for basil. 6. Keep basil mix evenly moist but never soggy. Do not let pots sit in standing water.
Windowsill Winter Garden
Outdoor basil will eventually flower and decline even indoors. University of Minnesota Extension recommends planning on new seed or nursery plants each spring. Keep a small tray of herb seeds going under a bright window or grow light for continuous leaves.
Browse catalog pages for basil, marjoram, cilantro, and all herbs.
Next Steps
1. Check nights against your first frost date. 2. Mark the move on Garden to Bed. 3. Protect one more outdoor night only if a light frost is forecast: protecting plants from early frost.