How to grow basil indoors

Basil is a delicious and fragrant herb commonly used in Italian cooking. If you’ve never topped your pasta or pizza with fresh basil, you’re really missing out!

Because it is used in so many recipes and is so easy to grow, it’s one of the most popular herbs that people grow at home.

Can you grow basil indoors?

The two basil plants on my windowsill are a testament that yes, you can grow basil indoors! Not only that — it’s an incredibly easy plant to grow and take care of. For basil to grow happily, the soil needs to be at least 50°F, but even warmer is better!

That means, in many places around the world, and during the winter basil struggles to stay alive outdoors. So, growing basil indoors allows you to enjoy fresh and delicious herbs year-round, no matter the weather.

Starting indoor basil from seed

Whether you plan to keep your basil indoors for the life of the plant, or if you plan to transplant it outside in spring when the soil warms to the proper temperature, you can easily start basil from seed indoors.

If you plan on transplanting, start your seeds around 6 weeks before your last frost date.

If you plan on keeping your basil inside, you can start your seeds any time of year!

Make sure that your home is warm enough to keep the soil at at least 50°F — that means a chilly windowsill or basement may not be conducive to starting and keeping basil alive. The ideal temperature for starting basil is around 80°F, and to continue healthy growth it should be kept in temperatures around 70°F to thrive and grow throughout its life.

Taking care of a basil plant you bought

Because basil is such a popular cooking herb, you can often find potted basil plants for sale at your local nursery or even the grocery store. However, these plants are often not taken proper care of with sufficient light and nutritious soil.

How to take care of an indoor basil plant

Because basil is a warmer-weather plant, it can be a bit finicky to grow indoors, but it is relatively easy to keep alive if you know how to care for it.

How much light does basil need indoors?

Basil thrives with at least 6-8 hours of sunlight, so make sure you keep your basil plant on a sunny windowsill. It can be a hard balance to strike during cold winters if your windows are older because basil cannot survive in a cold draft.

Your indoor basil will have the greatest chance of thriving in a south-facing windowsill because it will get the most and longest duration of direct sunlight and warmth.

Do you need grow lights for indoor basil?

Depending on how warm your house is and how much sunlight your windowsill gets, you may or may not need a grow light to help your indoor basil grow.

Grow lights can be helpful if you don’t have a good south-facing window, or if you are starting or growing your basil in a gloomier space, like a basement or closet.

Even if your basil is on a sunny windowsill, if you notice that it is struggling to grow or stay alive, you may want to try a grow light to see if the extra light helps it stay healthy.

How to prune basil to keep it growing

It is common for indoor basil to become “leggy” — or have long stems with few leaves. This is especially common for basil plants that you buy at the grocery store, that may not have had the best care previously.

Pruning (or trimming) your basil regularly will help it grow more abundant and lush, and keep it producing more leaves that you can harvest to enjoy in your kitchen.

Prune your basil if it is looking “leggy”, or any time that it has 6 or more leaves. You will want to prune your basil above the second set of leaves, which promotes better growth. Continue pruning throughout the year as your plant grows.

Watering your indoor basil

Basil thrives with moist soil so you will need to water your basil relatively frequently. Outdoor basil requires about 1 inch of rain per week, but houseplants sometimes need a little bit more than outdoor plants.

Typically, you will need to water your indoor basil about 2-3 times a week, as soon as the top layer of soil begins to look and feel dry. If your plant begins to wilt, that is a sign that you are underwatering!

Taking care of your basil plant during winter

Basil is a warm-weather plant, requiring temperatures around 70°F year-round, which means that it can only survive indoors during winter in most climates. If your home struggles to maintain a temperature of 70°F during the winter, a heat mat can be helpful to keep your soil warm enough for the plant to thrive.

During dark winter days, or if your basil isn’t in a south-facing window, it may also benefit from a grow light.

How long will an indoor basil plant live?

Outdoor basil is an annual, meaning that you plant it every year and it dies at the end of its growing season when the weather drops below 50°F. When planted in the ground, basil typically lives for about 4-5 months.

However indoor basil that is well cared for with warm temperatures, ample water, and nutritious soil, can live for six months or longer. Eventually, your basil plant will start flowering and seeding, and you can pinch off the flowers to eke out a few more weeks of life.

If you want basil year-round, it’s smart to start new basil every few months to replace the plants that will eventually die off.