Wintering Herbs Indoors

Some herbs are too tender to leave outdoors for winter and should be potted up and brought in. Others you want to enjoy all winter on your windowsill so you can snip for your favorite recipes. I've found there are very different requirements depending on whether you're just keeping them alive during dormancy or you want actively growing plants to use. And growing indoors when the light is as low as it is during winter is quite different from growing outdoors.

Plants to winter indoors for use are: rosemary, catnip, lemon verbena, scented geraniums, lemongrass, thyme, bay, chives, lemon balm, winter savory, sweet marjoram, oregano, parsley, mints, and sage. Beware the mints-the runners will take over the house just like they do outside (remove them or you'll have no leaves), and don't bother with St. John's wort or French tarragon-they don't like it inside or in pots at all, for that matter.

I plant herbs with the same light, soil, and water requirements together-thyme, marjoram, rosemary and sage, for instance.

The tender herbs like rosemary should be brought in as a whole plant or you'll forfeit what's left outdoors. Cut back tender perennials like lemon verbena, scented geraniums, rosemary, lavenders (if they are not hardy in your area) and lemongrass in midsummer and again before bringing them in. A special note on chives: Let the tops die back and the roots freeze before you dig them up and bring in.

Annuals, such as basil, dill, cilantro, and sweet marjoram (a tender perennial that should be treated as an annual) really cannot be dug up to bring indoors. Don't fret! You can still grow them indoors, just start them from seed, or buy them as plants in the fall specifically to grow indoors.

Some herbs like lemon verbena are actually deciduous shrubs and will lose their leaves when they go into dormancy. Don't panic. Keep the plants in a cool place, 40ºF is best, and don't water. In spring, they'll literally burst out into leaf. Scented geraniums don't lose their leaves, but they stop growing if you keep them this way. They should be kept on the dry side and watch them diligently for aphids. Aphids love them indoors!

Just pick the herbs according to what you like to use for cooking, and choose attractive pots. You will be living with these herbs as houseplants all winter.

Dig up the entire clump of perennial herbs, and divide the amount you want to bring in from the rest. Be careful not to disturb the roots. Pop the outdoor crop back into the ground and pot up the indoor herbs. These will winter inside and be transplanted out again once the spring comes. Let them sit in a shady spot for about 2 weeks before bringing in to help them adjust to the transition.