How to Grow Vegetables Indoors

  • 01 of 08

    How to Grow Vegetables Indoors

    Plants sitting on the windowsill
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    Winter weather doesn’t have to mean the end of harvesting fresh vegetables. You could always garden undercover, outdoors. Or you could try your hand at growing food indoors. Yes, it is possible to grow vegetables inside during the cold months or just because you lack outdoor space. However, it’s not the easiest way to garden and you shouldn't expect huge yields.

    The biggest challenges of growing edibles indoors are low light and a lack of pollinating insects and wind. However, on the positive side, you can control water, soil, and fertility. Unfortunately, pests and diseases may follow you indoors, but since the plants are right under your nose, you should be able to stop problems before they become major headaches.

    General Indoor Growing Tips

    • Use a good quality potting mix, not garden soil.
    • Containers should have good drainage and be sized for the particular plant. For instance, shallow and rooted greens only need about a two-inch depth, but deep-rooted tomatoes will want at least 12 inches of soil.
    • Sunny windows do not usually provide enough light for healthy, stocky plants. The days are just too short, and the light is too low in the sky during winter for a plant's needs. You might want to use some type of supplemental lighting; either a plant light or a full-spectrum fluorescent light.
    • Don’t place your plants so close to the window that they are subjected to drafts or close to a heat source that could dry them out.
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  • 02 of 08

    Carrots

    Close-up of fresh carrot in pot of soil
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    Carrots are ridiculously accommodating. Growing them in containers is not just a great option for indoor growing, it also solves the problem of trying to grow them in heavy, rocky soil.

    Smaller carrots are easiest to grow inside. They need less space and mature quickly. Since you’ll be seeding multiple plants—unlike a single pepper or tomato plant—a long container, such as a window box, is ideal. The key for good germination is to keep the soil moist. Just lightly cover the seeds with some damp peat moss so the seeds don’t dry out, but no hard crust forms over them, preventing germination. Seeds should germinate within two weeks. Days to maturity will depend on the variety you are growing.

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  • 03 of 08

    Garlic Greens

    Garlic plant grown indoors in jar
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    Garlic has very particular temperature needs to form bulbs, but you can easily have a steady supply of garlic tops or greens that can be used instead of scallions. You don’t need a large container for garlic sprouts. A depth of about four inches should suffice. Simply plant the individual cloves about one inch deep and water regularly. The cloves should sprout in about one week.

    Let them grow to eight to 10 inches before you begin harvesting. Cut off what you need and leave the rest. You generally only get one flush of growth from each clove. They may sprout again, but the quality declines, so start new cloves when you begin harvesting the current crop.

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  • 04 of 08

    Hot Peppers

    Growing ornamental hot peppers
    Marie Iannotti

    Even though pepper plants collapse at their first brush with frost, they are tropical perennials. You can try sweet or hot peppers, starting both of them by seed. You can also pot plants from your garden in late summer and to bring indoors for the winter. You won’t get a huge harvest, but they will fruit.

    Use a container that is at least eight inches tall. Hot peppers will need at least 10 hours of light each day. Don’t over water. Allow the container to dry out between watering. The plants are self-pollinating, but you may need to help them along. You can either jostle the plants to shake the pollen from one flower to another or use a cotton swab to dust each flower with pollen.

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  • 05 of 08

    Lettuce and Other Salad Greens

    Person planting lettuce in a wooden box
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    Lettuce is quick growing and shallow rooted, so it won’t need a deep container. It will also continue to regrow if you go the cut-and-come-again route. Choose a container that is two to four inches deep, and fill it with dampened soil. Sow your seeds and gently press them into the surface of the soil. Mist to keep the seeds moist and you should see germination within about one week.

    Allow the plants to grow at least four to six inches tall before you start harvesting. Cut or pull the outer leaves and allow the center of the plant to continue growing.

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  • 06 of 08

    Microgreens

    Radish (Daikon) leaves
    MarpleRosenow/Getty Images

    These tiny, fresh sprouts are probably the easiest edible to grow indoors. They don’t take up much space or much time. Microgreens are just a mix of seeds of various greens and herbs, such as beets, radishes, kale, Swiss chard, and basil. 

    Since these greens will be harvested as seedlings, you don’t need much soil. A shallow (two inches deep) tray works well. Fill it with soil, moisten it, and scatter your seed. Barely cover the seed with soil, but press gently so that the seed makes good contact with the damp soil and won’t dry out. Water with a gentle stream or spray to keep the soil moist, and you should see germination within days.

    Start harvesting when seedlings are they have developed about two sets of true leaves. Use a scissor to snip them off at the soil level and you may get another spurt of growth.

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  • 07 of 08

    Scallions

    Growing scallions indoors
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    You can’t grow bulb onions indoors, but scallions, such as garlic greens, do just fine. In fact, they may rival microgreens with their ease. You don’t even need seeds.

    Some gardeners have had success simply replanting the root end of scallions they purchase, after using the tops. You can root the whole scallion in a glass of water, and plop the bunch of them in one glass with only about one inch of water in the bottom. When the roots have reached a couple of inches in length, move them to a shallow container of potting mix and let them continue growing. You can harvest just the green tops, leaving about one inch of the stem to regrow or pluck entire scallions out of the container, to use the white portion.

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  • 08 of 08

    Tomatoes

    Reisentraube Tomatoes
    Marie Iannotti

    You usually see tomato plants die off at the end of the season, but tomatoes are tropical perennials. It's probably best to leave these garden plants outside since they're usually too large and already experiencing problems by the end of the season. However, starting a new plant from seed at the end of summer can be grown on indoors. Tomato seeds germinate fairly quickly. Once the seedlings are three to four inches tall, move them to their “permanent” pot and make sure they have at least 10 hours of light per day. It’s a lot, but this is a fruiting plant and it needs that much light during winter.

    Start feeding with a water-soluble organic fertilizer when you move the seedling to its new pot. Once the plants start setting flowers, you will need to shake them periodically to allow the pollen to fall from flower to flower. Without pollination, no fruits will form. The plants can become top heavy and staking may be necessary.