Basil is one of the easiest herbs to grow indoors, and its delicious flavor and culinary popularity make it a must-have for gardeners and cooks alike. With the proper conditions, basil grown indoors can be just as successful (if not more so) than plants that are grown outdoors.
Though it's traditionally associated with Italian and Mediterranean cooking, basil is actually native to Asia. Best planted in early spring outdoors or year-round indoors, basil will grow quickly, establishing in just three to four weeks. The plant features small, shiny green leaves that grow in bunches and possess a very distinct aroma. Approximately 75 days after planting, your basil may begin to flower—simply snip off the blooms to prolong your plant's vegetative phase.
There are dozens of types of basil, each of which has its own unique flavor and attributes. Some of the most popular varietals suited to indoor growing include:
- Ocimum basilicum 'Genovese': Commonly referred to as Italian basil, this varietal has large green leaves and a sweet, quintessential basil flavor.
- Ocimum basilicum 'Purple': Beloved for its striking rich purple hue, this varietal has pointy leaves and a rich, almost licorice-like flavor.
- Ocimum basilicum x citriodorum 'Lemon basil': A hybrid plant, this varietal has thinner, more delicate leaves and is very popular in Asian dishes thanks to its distinct citrus taste.
|Botanical Name||Ocimum basilicum|
|Common Name||Basil, sweet basil|
|Mature Size||12–24 in. tall, 12–24 in. wide|
|Sun Exposure||Full Sun|
|Soil Type||Moist but well-drained|
|Soil pH||Neutral to acidic|
|Bloom Time||Summer, fall|
|Flower Color||White, pink, purple|
|Hardiness Zones||2–11 (USDA)|
Can You Grow Basil Indoors?
As with many other herbs, basil is a true sun-lover—give it bright light each day, and it will thrive. Alternatively, basil does exceptionally well under grow lights, so you have the opportunity to increase your harvest and grow enough basil to keep your kitchen stocked throughout the year. Basil requires a pot just big enough for the plant, so starter plants can fit quite well in even the smallest apartment space.
How to Grow Basil Indoors
Basil is a uniquely rewarding plant to grow—it's relatively pest and disease-free and is delicious in both fragrance and taste. Basil's taste will change throughout its life cycle, becoming stronger as the plant flowers—basil that has flowered can still be eaten, but it may be a bit bitter. The herb responds well to pruning and topping, so feel free to use leaves as soon as the plant is established and has branched out.
Whether being grown indoors or outdoors, basil plants need ample light—at least 6 hours of full sun daily. If you're using fluorescent bulbs, keep your basil under them for 12 hours a day, with the lights about 2 to 4 inches away from the top of the plants. Be careful not to let the leaves touch the bulbs to prevent burning.
Temperature and Humidity
Keep your basil somewhere in your home that boasts an average temperature of 70 degrees Fahrenheit or higher. Avoid putting the plant anywhere it may be subjected to a harsh or cold breeze, like in front of an open window in the winter or near an air conditioning unit. Basil plants also like a fair bit of humidity, so mist your plant occasionally, especially if your home is particularly dry. If you find you need an added bit of moisture, you can place your basil container on a bed of wet river rocks to increase the ambient humidity around the herb.
For best results, aim to keep your basil plants regularly moist. Basil thrives best when it receives about 1 inch of water a week, but plants housed in containers often need a bit more than that. Water your plant once the top layer of soil has dried out, or when the plant shows the first signs of wilting (though it's best to not wait for that as a signal).
If you've previously amended your soil with organic compost, there's a good chance that your basil plants won't need additional nutrients. However, if you notice your plants aren't experiencing much growth, you can feed your basil plant once a month using a weak liquid fertilizer.
Pruning and Maintenance
Basil is a hardy plant that needs little maintenance. Well-drained soil, good air circulation, occasional watering, and plenty of sunlight are enough to keep a basil plant in good shape. Harvesting is effectively pruning the plant, as the leaves should be taken from the top down. Cut off individual leaves from smaller plants, or snip stems a few inches down for larger ones.
Container and Size
To avoid potential fungal growth on the plant, basil needs a container that allows for good airflow and excellent drainage. To this end, a fabric pot filled with high-quality potting soil can help basil thrive.
Potting Soil and Drainage
Basil plants prefer a soil mixture that is moist but well-draining. For best results, amend your potting soil with a bit of organic compost before planting your basil indoors. Beyond that, make sure to choose a pot for your plant that boasts ample drainage holes at its base so the soil doesn't get soggy or waterlogged.
Potting and Repotting Basil
Most people eat their basil before they can repot it. If you're growing from seed, step up seedlings from a seed starting tray after two weeks into a 4-inch pot, which will likely be their final home. Pinch the herb after the newly repotted plant is established to encourage more leaves. Basil responds well to pruning, but don't expect indoor plants to get quite as large as those grown outdoors.
Moving Basil Outdoors for the Summer
Basil doesn't like the cold. Move it outside only after temperatures are consistently about 50 degrees Fahrenheit. As winter approaches, bring basil inside before the first frost.
How do you grow basil from seed?
Basil plants start readily from seed, especially when placed under grow lights. Most basil varieties will germinate in about five days when kept at temperatures around 80 degrees Fahrenheit (a heat mat can be helpful to achieve these conditions as well). Lower temperatures will increase germination time.
How do you harvest basil?
When basil leaves grow to the size of your liking, simply snip them off with a pair of kitchen scissors or pull them off by hand.