How to: Overwinter Herb Plants Indoors
Choose a sunny, south-facing window to overwinter your herbs so they get the most light in winter.
There's nothing like the taste of fresh herbs in cooking. However, in most parts of the country, fall means the herb harvest is coming to an end. If you live in a mild winter area, you can enjoy harvesting perennial herbs that naturally overwinter outdoors, such as rosemary, lavender, oregano, and thyme, as you need them all winter long. However, in most parts of the country, perennial and biennial herbs either lose their leaves in winter or just aren't hardy enough to survive at all.
You certainly can dry and freeze herb leaves for winter use, but if you crave the taste of fresh herbs in winter, bring some of these perennial herb plants indoors. Whether they were growing outdoors in the garden or in pots, you can extend the fresh herb picking season by months by bringing the plants in when frost threatens. This technique works best for perennial and biennial herbs, such as chives, mint, oregano, thyme, parsley, and rosemary. Annual herbs, such as basil, tend to tire after a few weeks indoors. Annual herbs are best started from seed indoors under grow lights and grown as new plants for a winter harvest.
Here are the steps to bringing your perennial herb garden indoors.
Who says overwintering herbs can't be displayed in an attractive fashion?
Rosemary can be overwintered indoors if given plenty of humidity and light.
- Select the healthiest herb plants in the garden. Don't necessarily select the largest plants. The digging and transplanting process will destroy many roots. Small to medium-sized plants will survive better.
- Check plants for any signs of insect activity and spray accordingly with an organic product, such as insecticidal soap, before moving them indoors.
- Water plants well and dig up herb plants in the garden on a cool, cloudy day. Place them in an appropriately-sized pot.
- Place these newly transplanted herb plants in a shady spot to adjust to the transplanting for 1 to 2 weeks. Keep them protected from winds and cold temperatures.
- Move container herbs that have been growing in full sun outdoors all summer into the shade at the same time. The lower indoor light conditions will be a shock to most plants, so acclimate them to the indoor environment by growing them in the shade outdoors for a few weeks.
- Before a frost, bring all the herb plants indoors and place them in a sunny, south-facing window.
- Check for any insects that have hitched a ride indoors on your plants.
- Water sparingly and don't fertilize.
- Most herbs will grow slowly, or not at all, indoors in winter. Harvest what you need, but leave some leaves for the plant to survive. You'll see your plants rebound come late winter when the stronger light levels and longer days return. The exception is parsley. This biennial herb will survive the winter only to send up a flower stalk in spring and then die. Pick all the parsley you want and compost the plant when you're done.
- Rosemary has special needs to survive. It likes cool temperatures (50- to 60-degree F), high humidity, and barely moist soil in winter. Keep the humidity high by misting often, and place the pot on a pebble tray filled with water. Water the pot just enough to keep the soil from drying out.
- Come spring, once all danger of frost has passed, move your perennial herb plants back outside. Repot them into pots with fresh potting soil, or transplant them into the garden. They will bounce back and start putting on new growth in no time.
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