You can bring your herb garden indoors for the winter—or all year—by planting a windowsill herb garden. It's not as easy growing some herbs indoors as it is outside, but many herb plants grow quite well in containers and require only minimal care. However, there are a couple of 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
Steps to Successfully Grow a Windowsill Herb Garden
- Make sure you have a sunny windowsill where your herbs will survive. A south or southwest window would be perfect if it gets at least six hours of sun per day and is away from drafts. If you don't have a reliably sunny window, you will need to provide some type of plant lighting. A lack of sunshine will leave you with spindly, stressed plants with little flavor.
- Purchase some of your favorite small herb plants or seed packets. Starting from seed is relatively inexpensive. But the plants require more attention, and it will be several months before you can start using them.
- If you are starting with nursery plants, get a container that is at least 6 to 12 inches deep. You can plant multiple herbs in a wide or long container, or use at least a 6-inch pots for individual plants. Seeds won't require a large pot at first. You can start them in any small container, and move them into their final pot when they are 2 to 4 inches tall. Just like outdoor container gardening, make sure your pots have plenty of drainage holes. Unlike outdoor plants, also make sure you have a saucer under them, so you don't ruin your windowsill or furniture.
- Use a good organic potting mix to avoid soil-borne diseases. Be sure the mix is light and well draining. Don't try to use soil from the garden. Regular soil compresses over time, making it difficult for water to pass through.
- For herb plants, start by putting a 2- to 3-inch layer of potting mix into the bottom of your container. If you are worried about soil coming out of the bottom holes, you can cover them with a piece of screen. Don't use anything that could block the holes entirely.
- Carefully remove the herb plant from its original pot, and gently loosen the roots. Place your herb plant in the new container with the roots flared out.
- Finish filling in with the potting mix, firming gently around the plants. Leave about an inch of space at the top of the container for watering. Water immediately after planting to help the plants settle.
- To start herb seeds, fill each container with dampened seed-starting mix to about 1 inch from the rim. Sprinkle three to five seeds on top of the soil. Cover the seeds lightly, and pat down gently. Cover 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 whenever the soil feels dry. Be sure the seedlings are receiving plenty of sun and rotate the container daily, so they grow straight.
- Water herb plants sparingly. Herbs don't like to sit in wet soil. Drain the saucers when excess water accumulates.Test to see whether the containers need water by poking your finger into the soil. If it feels dry an inch or two below the surface, it's time to water. If not, let them be. Although outdoor plants tend to need more water in the summer, indoor plants can dry out quickly when the heat is on in the winter. Water until the excess drains out of the bottom of the container. If you repeatedly give your indoor plants just a splash of water, the salts in 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. Thoroughly flushing water through the container until it drains out the bottom will prevent salt buildup
- Feed your herbs every other month with a fertilizer labeled for use on edibles. Start by using it at only about half the recommended strength. Herbs have more concentrated flavor if they are grown without a lot of fertilizer. If you are seeing a lot of wispy, delicate growth, lessen the amount or frequency of fertilizer. If your plants look like they are struggling, give them a bit more. You will need to adjust your fertilizer schedule with the seasons. In general, they will grow more slowly in winter than summer and will need less food then.
- Allow the plants some time to acclimate to their new home. Once you start seeing new growth, you can start using your herbs. With most herbs, you can snip 2 to 3 inches of the tips off to encourage more branching. For bushy herbs, such as parsley and cilantro, you can cut entire stems from the outside of the plants. New growth will fill in.
Tips for Indoor Herb Gardens
- Choose herbs that don't grow too wide or tall. Chives, basil, lavender, parsley, mint, rosemary, and thyme are good choices.
- Fluorescent lights can be used if you don't have a sunny window. They will need to be placed close to the plants (within 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 from seed, the lights will need to be kept within about 2 to 3 inches from the top of the growing container until the seeds 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.
- Snip and use your plants often to encourage them to grow full and bushy. Once the plants are at least 6 inches tall, don't be afraid to use your herbs. The more you snip, the bushier they'll become.
- Never trim more than a third of the plant's foliage. Pruning more than that can stress the plant and cause it to decline.
- Start seeds of new plants to replace the ones you are using. No plant lives forever, and many herbs, such as basil and dill, are actually annual plants that will try to go to seed within four to six months. Don't fight it; just replace them with new, vigorous plants the way you would in an outdoor garden.