Summer vacation is wonderful for people with culinary herbs. While you enjoy longer days and uninterrupted stretches of shorts-and-sandals weather, your plants are basking in summer sunshine and warmth. Basil grows bushy, thyme exudes powerful fragrance, and mints threaten to take over the landscape. You can harvest herbs whenever you need them, secure in the knowledge that the summer garden will provide an ever-ready supply.
But eventually fall rolls around, and herb production begins to drop off. Frost, just around the corner, will kill the annual and tender perennial herbs, while forcing many hardy perennials into dormancy.
Some gardener/cooks simply harvest as many fragrant leaves as possible and dry or freeze them for the winter months. This is a great solution to the fresh herb drought, but there is another option that is equally satisfying: bringing those herb plants into the house.
Not all herbs succeed equally well indoors, but many do, and with a small amount of effort and expense, it is possible to create an herb garden in just about any living space.
Create the Right Conditions
All herbs need light—the more the better. If you have south-facing windows available, requisition them for your overwintering plants. A wide windowsill, shelf, or plant stand is preferable. If those options are not available, a shelf that attaches to the window with suction cups will do nicely. Just make sure it is secure enough to hold your potted plant. East and west-facing windows will provide enough light for some herbs, but avoid northern exposures unless you provide supplemental lighting.
If south-facing window space is at a premium and some herbs are in east or west-facing windows, rotate the plants regularly, allowing each one to have its moment in full sun. Even southerly window glass transmits cold, so pots should not hug the panes. Also avoid situating the herbs over a radiator, or another heat source, because this will stress plants and cause the soil to dry out more quickly.
If your windows just don’t provide enough light, you can still enjoy herbs indoors by investing in either fluorescent grow lights, full-spectrum LED lights, or full-spectrum plasma lights. Fluorescent grow lights are the least expensive and are probably all you need if you are a novice or casual herb grower. Whatever type of light you choose, position the unit directly over the herbs (to mimic sunlight) and adjust the height according to manufacturers’ directions. As your plants grow, you will probably need to readjust the light.
Potting Up and Moving
Herbs already growing in pots are easiest to move indoors. When the plant comes in, clean off the pot and check the leaves—including the undersides—for hitchhiking pests. Eliminate them with a strong spray of water and some insecticidal soap. If you see mineral build-up from fertilizer on the insides of containers, flush thoroughly until water drains out of the bottom holes. Make sure that all containers have adequate saucers to catch excess water to keep windowsills and other surfaces damage-free.
Herbs that have spent the summer in-ground can be dug and potted-up or you can take cuttings from the plants. To dig plants, carefully dig around the rootball (roots and soil) to capture many of its roots. If you are dividing a perennial herb, like chives, dig up the entire plant and rootball and use a garden knife or trowel to divide the plant in half. Replant one half in the original hole and pot up the second half. Choose a container at least a few inches wider than the root ball, and check to make sure it has a drainage hole at the bottom. Fill in around the root ball with OMRI Listed Fafard® Natural & Organic Potting Soil. Firm up the soil around the plant and water well.
To take cuttings, simply snip healthy stem tips, dip them in plant rooting hormone, and place them in pots or trays of a moist mix. Basil, rosemary, sage, oregano, and mints are the best rooters and usually take just a week or two to establish new roots.
Right Plant, Right Place, Indoor Edition
If you are divvying up your available sunny window space, reserve the southern exposures for plants like oregano, rosemary, basil, lemongrass, bay laurel, and thyme, which are native to warm, sunny climates. East- or west-facing windows will make congenial homes for various mints, chives, cilantro, and parsley. Turn the plants regularly and water them when the surface of the soil is dry to the touch.
Once your herb plants are safely indoors, they may look unhappy for a time while they acclimate to their new surroundings. Herbs that you dig and pot up may experience some transplant shock. Be patient and most will recover. Sometimes basil peters out and becomes woody. If this happens, take four-inch cuttings from the plant. You can also resort to planting basil from seed. Their seeds germinate in one to two weeks and should have enough leaves to harvest within a month.
If you are not sure about bringing herbs into your living space, try it with one or two varieties. Fresh herbs give you a taste of summer sunshine even in the midst of a January snowstorm.