Delicious, fragrant herbs grow all summer long, filling the garden with fragrance and adding to recipes and herbal teas. But once frost threatens, it's time to say goodbye to some of your herbs until the next growing season.
The good news is that you can bring many of these tender herbs indoors. Grow them in a sunny window or under grow lights and you can keep enjoying them for several more months.
Best Herbs to Grow Indoors
Some herbs acclimate better to indoor conditions than other herbs. The best herbs to dig up from the garden to grow indoors are:
For chives, thyme, and oregano, simply shake off most of the garden soil from the roots, re-pot the plant with good organic potting soil, and set it near a sunny window.
Growing parsley indoors can be trickier. It has a long taproot and does not react well when it's disturbed. If you're planning to dig it up from your garden, dig deeply to get as much of the taproot as possible. Then re-pot the plant into good potting soil in a deep container—preferably eight to 10 inches.
Rosemary can be finicky about temperatures. It does best in a bright window in a cool room. A south- or east-facing window would be best.
Other Herbs to Grow Indoors
You can also grow basil fairly easily in a bright window, however, do not dig it up from the garden as you would with other herbs. Instead, either start new plants from seed, buy a small plant to grow indoors, or take cuttings from one of your existing plants. The same can be done with lemon balm, mint, or shiso.
How to Care for Herbs Indoors
If you're planning to overwinter your garden herbs indoors (or at least keep them growing long enough to get a few more harvests from them), here are a few things to keep in mind:
Herbs do best with plenty of bright light—at least 6 to 8 hours of light per day. You can place them in a south-facing window, but the more guaranteed method is to place them under grow lights, which are usually used for seed starting.
One of the trickier things about overwintering your herbs is maintaining the right moisture level. You'll want to water them regularly, but many herbs such as thyme, prefer dryer conditions and dislike soggy soil. Rosemary should never dry out completely. The most effective way to determine if it's time to water is to do the finger test: stick a finger into the potting soil. If the top inch of soil is dry, it's time to water.
Before you bring your plants indoors, check the plants thoroughly for pests. Keep the plants separate from the rest of your indoor plants for a few weeks to make sure that any pest or disease problems do not spread. Once this initial period has passed, check your plants regularly for insects, eggs, webs, or fungi. Look underneath the foliage as well—this is where many pests tend to congregate.
With herbs or any other plant you're growing for consumption, use integrated pest management strategies that don't involve chemicals as your first line of defense against pests. Give your herbs the best conditions possible to grow; remove any pests you do find by picking or gently shaking them off; and remove affected any parts of the plant. As a last resort, you can spray them with horticultural oil or insecticidal soap if you see any insect activity.
Indoor Herb Gardening Pests Management Strategies. University of Vermont.