You can bring your herbs indoors for the winter—or all year—by planting a windowsill herb garden. Many herb plants grow quite well in containers and require only minimal care. However, there are some extra considerations when growing them indoors. Providing adequate sunlight and enough space are key.
Here are some helpful tips to set up your indoor herb garden.
Watch Now: How to Grow Herbs Indoors on a Sunny Windowsill
Pick a Spot for the Indoor Herb Garden
A lack of adequate light will leave you with spindly, stressed plants that have poor flavor. So make sure you have a sunny windowsill where your herbs will survive. A south or southwest window is ideal, as long as it gets at least six hours of sun per day and is away from drafts.
Grow lights can be used if you don't have a sunny window. In general, they will need to be placed close to the plants (within roughly 18 inches) and kept on for about 10 hours per day to make up for their lack of intensity.
Note that if you are starting plants from seed, the lights will need to be kept within about 2 to 3 inches from the top of the growing container until the seedlings emerge. The lights can then be raised gradually until you are ready to transplant. If you keep the light raised too high over young seedlings, it will cause them to grow leggy.
Choose Your Herbs
Choose herbs that don't grow very wide or tall, as they will do best in containers. Chives, basil, lavender, parsley, mint, rosemary, and thyme are good choices. You can purchase nursery plants or seed packets. Starting from seed is relatively inexpensive. But it requires more attention, and it will be several months before you can start using the herbs.
Set Up Containers
To start herb seeds, fill a container with dampened seed-starting mix to about 1 inch from the rim. Sprinkle three to five seeds on top of the soil, cover them lightly, and pat down gently. Cover the container with a plastic bag or dome to retain moisture and increase humidity.
Keep the soil moist until you see the seedlings poking through. At that point, remove the plastic and continue watering to keep the soil lightly moist but not soggy. Be sure the seedlings are receiving plenty of sun. Rotate the container daily, so they grow straight. Move seedlings into a larger container when they reach roughly 2 to 4 inches tall.
If you are starting with nursery plants, get a container that is at least 6 to 12 inches wide and deep. Depending on their mature size, you might be able to situate multiple plants in one large container. The container should have drainage holes and a saucer to catch excess water. You can use a piece of screening to cover the drainage holes and prevent soil from coming out, but make sure it doesn't block the water drainage.
Use a quality organic potting mix that's light and well-draining. Don't try to use soil from the garden. It can carry pests and diseases. And garden soil compresses over time, making it difficult for water to pass through.
Add a few inches of potting mix to the bottom of the container. Then, carefully remove the herb plant from its original pot, and gently loosen the roots. Place the herb plant in the new container with its roots flared out. Finish filling in around the plant with potting mix, gently firming the soil. Leave about an inch of space at the top of the container for watering. Water immediately after planting to help the plant settle.
Care for Your Herbs
Herb plants have varying water needs, so make sure to check what your specific herbs require. In general, herbs don't like to sit in wet soil. So drain the saucers immediately when excess water accumulates. Moreover, note that container plants dry out more quickly than those grown in the ground. And dry indoor air also can up your plants' water needs.
Water until the excess starts to drain out of the bottom of the container. If you repeatedly give your indoor plants just a splash of water, rather than flushing the soil, the salts from the water can build up in the soil. When this happens, you'll start to see a white film on the outside of the pot.
Herbs also have varying fertilizer needs. Make sure to choose a fertilizer labeled for edible plants. In general, if you are seeing a lot of wispy, delicate growth, lessen the amount or frequency of fertilizer. But if your plants look like they are struggling, give them a bit more. You also will need to adjust your fertilizer schedule with the seasons. Herbs generally will grow more slowly in the winter than in the summer and will need less food then.
Allow the plants some time to acclimate to their new home. Once you see new growth (or once seedlings reach at least 6 inches tall), you can start using your herbs. With most herbs, you can snip 2 to 3 inches off the tips for harvesting as needed. This also will encourage more branching and lush growth. For some herbs, such as parsley and cilantro, you can cut entire stems from the outside of the plants, and new growth will fill in.
Never trim more than a third of a plant's foliage at one time. Pruning more than that can stress the plant and cause it to decline.
Repeat the Process
No plant lives forever, and many herbs are actually annual plants that will try to go to seed and then decline during their first year. Don't fight it; just replace them with new plants the way you would in an outdoor garden. As plants hit maturity and begin to decline, start a new batch of seeds (or shop for nursery plants), so you're never without fresh herbs.