Growing Basil Indoors

July 23, 2021July 22, 2021 by Marisa Dallas

I have always had trouble growing basil from seed indoors! Maybe this guest post from Jenn Stark, an Editor at Happy DIY Home will help me. I did grow the African Basil this spring and it did grow very well, however, the flavor was horrible. – Robert

How to grow basil indoors? Growing basil plants is one of my favorite hobbies.

I hope you had an amazing summer overloaded with fresh garden fruits and vegetables.  I know summer is coming to an end when the farmers market heats up with the season’s final produce.  My potted tomato and basil plants topple into each other on my patio as if they couldn’t resist themselves.  I always keep basil on hand by growing it indoors year round so I can add fresh basil to many of my dishes and sauces.

Why You Should Grow Basil 

There’s a few things that are better than clipping fresh basil leaves from your windowsill or garden and adding it to your dishes right when you start cooking. The question you should ask is, why shouldn’t you grow basil? It has a spicy, fresh, clove-scented flavor to it, and it’s a nice addition to many cuisines and cooking styles. 

Just having a well-pruned plant will supply you with around a ½ cup’s worth of basil every week. Even if you only have limited space, you need to find a sunny windowsill, fill a container with well-drained potting soil, and you’re able to get basil for months. 

The most common cultivar is sweet basil or Genovese basil, but you can also cook with lemon, Thai, cinnamon, and globe basil are all readily-available. One of the biggest differences between basil and other types of herbs is that it’s a tender annual. It’s extremely sensitive to the cold, so you’ll have to plant it soon. May is the best month to start growing your basil. 

Defining Basil 

Basil plants are very popular, and they’re native to the South Pacific’s islands and southern Asia. It’s a member of the mint family that you can grow it easily. You can consider it a tender annual, and it produces aromatic leaves that are commonly used in Mediterranean and Italian dishes. Basil seeds are very popular in Thai food. 

Because this plant is annual, it grows very quickly. It can go from seed to harvest in three to four weeks, so you’ll be able to use it in your food. This is an easy-growing and quick herb that is a great choice for beginner gardeners. 

Varieties of Basil

There are dozens of basil varieties available, and it’s easy to fill your entire herb garden with just basil. A few fan favorite varieties include: 

  • Green Ruffles – This plant looks nothing like you’d like traditional basil would. It has very pretty ruffled leaves that are very mild, and it goes well in salads. 
  • Lemon and Lime Basil – Both of these basil cultivars have a very bright citrus flavor. You can easily use them in a huge range of sauces, marinades, teas, and desserts. 
  • Purple Basil – This basil won’t give you a very strong flavor, and it also has a very pretty deep burgundy coloring. This color will translate into your dishes and garden. 
  • Spicy Globe  – This cultivar is a mounding, small basil. It has leaves that are smaller than other varieties of basil, and they come packed full of flavor. It works great in containers and small spaces. 
  • Sweet Basil – Planting this type of basil is simple, and this is the traditional basil that you can find sold in most grocery stores. This cultivar has medium green leaves in a slightly rounded shape. 
  • Thai Basil – This is another sweet basil that has pointed, smaller leaves. Growing this basil is the same thing as growing any other variety, but you get a slightly spicier leaf on it that keeps the flavor profile well if you use them in stir fries. The purple flowers are edible and beautiful too. 

Fend Off Frost

For those of us in northern climates, some of our tender leafed varieties have already objected to the frosty mornings and it’s high time to bring those plants inside so we may continue to enjoy the shine of summer in our fall and winter dishes.  There is a lot to gain by growing basil indoors during the time of year when colder temperatures or a blanket of snow makes it hard to keep bounteous aromatic green leaves outside of a greenhouse.

Why The Trouble?

Besides the delicious flavor, basil is an aromatic herb used in many styles of cooking the world over.  Basil combines beautifully with the ubiquitous tomato or minced and sprinkled over grilled peaches. It is amazing infused into oils and can be added to seafood dishes.

It has many health benefits and it brings me joy just to grow basil.  The wide glossy basil leaves, its fragrance and even the feathery flowers I pinch off now and then all add to the fullness of my life.

5 Easy Steps to Grow Basil Indoors

  1. To bring a plant inside from your garden just follow one or two stems to the dirt and cut out as much of the attached root ball as possible with a garden trowel.  Take as much of the root system as your pot size will permit.  The goal is to keep the roots intact and as undisturbed as possible when growing indoors.
  2. Pot the basil plants with extra potting soil and give it a little water.
  3. Use sharp pruners to prune away any flowers that may have gone to seed over the summer.
  4. Also remove any thin leggy unproductive stems that just compete for nutrients with the main plants.
  5. Bring your basil pot indoors and place it in a warm sunny spot. When growing indoors, basil is one of those plants that requires warmth from its roots to the outer basil leaves.

Hedge your Bets: Tips for Success on Growing Basil Indoors

I sprinkle basil seeds along with the newly potted plants.

If planting from seeds, space the basil seeds 10 inches apart.

You can harvest basil seeds from the flowers or use last spring’s seed packet.  This gets a few plants started just in case you caught your plant too late in the season.

This strategy is handy to get a head start on the seedlings you hope to plant outside when the weather warms.

When that time comes, you just have to remember to acclimate your plants to the outdoor weather conditions.  In early spring, it’s advisable to bring your plants indoors at night to guard against unexpected weather. They will not be happy if your area experiences the onset of hail or other seemingly spontaneous instances of basil plants damaging weather.

Good Warm Soil Composition Equals Great Taste

Basil plants, chives and parsley are great to have on hand when cooking. 

Nutrients are taken directly from the soil and into those bright flavorful leaves.  Good soil directly impacts the intensity of the basil flavor. A good base to start with is the commercial seed start soil found in garden centers.  I also mix in rich mature compost and fertilizer to feed the soil ecosystem.  While you should keep the soil moist as basil likes moist soil, make sure the moist soil is well drained and that you didn’t add too much of the fertilizer.

Compost can hold onto water like a sponge. Sand definitely has its place in soil composition and will help to correct the drainage if you went a little crazy with the fertilizer.  Strong root systems are made because a plant’s roots are seeking water not just drowning in it. Water once or twice a week and you are all set.

When growing basil indoors, it is important to remember that soil temperature is critical.  According to West Coast Seeds the soil temperature must be 70°F for your seeds to germinate and you can expect to see basil sprouts in no time.  I recommend using a seed heating pad for this scenario.  Your basil will appreciate it!

Lighten up

Another consideration to successfully grow your rescued basil plant indoors is providing your plants with UV light that mimics natural sunlight.  The good news is that what’s good for the goose is good for the gander.  UV light (and basil) can help keep the winter blues at bay.

Be cautious of placing your basil plants on a window sill.  A window on a winter day won’t be quite up to the task of providing the right quality of full sun sunlight and can be too drafty for the basil which can negatively impact the soil temperature. Try to make sure your plant gets at least six hours of sunlight a day.

We recommend a broad spectrum UV light.  Utilizing different wavelengths produce various characteristics in the basil plant mirroring the seasons and the plant’s natural life cycle.  For instance, blue spectrum wavelengths help seeds to sprout while red spectrum wavelengths may be more concentrated in late summer sunlight to produce larger leaves.

Planting Basil from Seed

The easiest way for you to start basil from seed is to directly sow it into your garden once you don’t have a spring frost that threatens it anymore, you can still start it indoors. Starting them indoors is a simple process that lets you get your hands in the dirt and it’s too cold outside. 

Materials Needed:

  • Basil seeds
  • Seed starting mix
  • Spray mister
  • Starter pots
  • Starting container with plastic dome

Step One: Prepare the Seed Pot

  • Prepare your starter pots by adding a slightly moistened seed starter mix until it’s ½ to 1-inch below the top of the seed pot or container. Since the pots are slightly smaller, you can do this by hand. 

Step Two – Add Basil Seeds

  • Add basil seeds to every pot. The goal is to put a few seeds into the center of the pot and pick the strongest plants after the seeds germinate. Some seeds won’t germinate, so adding a few extra to the pot increases how successful you’ll be. 

Step Three – Cover the Seeds 

  • Once you place your seeds, you’ll cover them with a ¼-inch of dry seed starter mix and leave them alone. 

Step Four – Mist the Seeds

  • Get water and gently mist your basil seeds. You’ll need a spray bottle with a fine spray, a specialized garden mister, or you could even lightly spray them from your faucet. The goal is to dampen your starter mix to ensure the seed makes good contact with the soil. 

Step Five – Humidity Levels 

  • Keep the humidity levels in by putting your basil seeds in a specialized plastic starting container with a plastic dome. You could also get a shallow pan with plastic wrap to make an DIY seed starting solution. 

Step Six – Put it in a Warm Location 

  • Put your newly planted basil in a warm location where the temperature stays around 70°F. You won’t need to water the basil seeds again until they start to sprout, so just keep an eye on them. 

Step Seven – Monitor The Seeds

  • Your seedlings will emerge within 7 to 10 days. At this point, you can remove the plastic wrap or plastic dome and put your basil in a sunny windowsill. Keep the soil moist by misting them frequently. When the true leaves start to appear on the seedlings, pick the strongest ones in each pot as you main seedlings. You can pinch the other seedlings off to remove them without disturbing the plant’s roots. 

Step Eight – Transplant 

  • When the seedlings have three pairs of leaves and aren’t ready to go outside yet, you can transplant them in three to four-inch pots. Add in a weak fertilizer solution to give them a shot of nutrition. 

Step Nine – Outdoors 

  • Move your basil seedlings outdoors at a gradual pace to slowly harden them off. This will let your basil adjust to the harsher outdoor conditions without going into shock. Once your temperatures reach the 70s, you can move them outside to a sheltered location for a week before transplanting them. 

Transplanting Basil Into Your Garden

No matter if you purchased your basil seedlings at your local garden center or you decided to start them indoors, once your weather gets to 70°F, it’s time to move your plants into your vegetable, herb, or flower gardens. 

Step One – Pick a Location 

  • Pick a location with a lot of sunlight. This herb does very well in warmer temperatures and full sunlight in the morning hours. If you live in an area where the sun is scorching, you should have shade in this spot during these hours. 

Step Two – Amend the Soil 

  • Amend the soil with a lot of organic matter before you plant the basil to create a well-draining, rich foundation for your plant. The garden container or bed should be at least eight-inches deep to promote strong root growth. 

Step Three – Spacing

  • Space your plants between 12 and 16-inches apart to allow for plenty of airflow and sunlight. Dig your hole using a garden tool, and make sure you judge the distance to space them correctly. 

Step Four – Plant the Seedlings 

Put your seedlings into the ground so the root ball is level with your soil. Use your garden tool to fill in any gaps. Use your hands to push the soil firmly around your newly transplanted basil. 

Step Five – Water

  • Water the basil and apply one or two inches of mulch around each seedling to help conserve moisture and prevent weed competition. 

The Rewards of Growing Basil Indoors: Cooking with Sweet Basil and Thai Basil

Smear basil aioli on toast for an intense flavor.

There are many varieties of basil that you can grow.  My favorites are sweet basil and Thai basil. Sweet basil is a delicate and aromatic herb that you can mince with a sharp knife.  Simply add basil to mayonnaise for a basic aioli. Thai basil can be grown alongside common sweet basil. Because it holds up better to heat, Thai basil is ideal for wilting into sauces at the end of cooking.  To me, Thai basil lends a bit of mystery to a dish with warm licorice or anise flavor.

At the end of the growing season, keep your basil.  Use these tips and strategies to bring and grow your basil inside.  It’s empowering and during the short nights of winter it will add the right amount of warmth to your plate.  Your day will be made brighter for it. I would like to know how you plan to enjoy your indoor basil.

How to Harvest Basil

Basil doesn’t get harvested at a specific time, and you usually just grab a few leaves as you need them. However, harvesting it regularly will keep your basil less leggy and rounded. It also stops the plant from going to seed. 

  • Harvest Your Basil Regularly – Even if you don’t need to keep harvesting your basil consistently throughout the growing season, you should. The goal is to remove ⅓ of the leaves from your plant each month to encourage new growth. You can add basil to several dishes, or it freezes well if you add olive oil. 
  • Snip Correctly – Snip your basil just above the point where two leaves meet. A simple pair of garden shears is all you need to help you create tidy and clean cuts whenever you harvest your basil. Enjoy the leaves fresh for the best results. 

Basil Care Tips 

Growing this plant isn’t difficult. With a small amount of care, your basil could grow so rapidly that you have extra leftovers to freeze for later use. A few simple care tips you can adopt include: 

  • Avoid Bolting – Also called going to seed, you can stop your basil from bolting by monitoring it well. Basil tends to bolt once the summer days stay consistently hot. You can stop this from happening by keeping the soil moist around the clock and giving your plants light shade during the hottest portion of the day. You can also pinch off the plant’s flowering stems an inch below the flower to keep it from becoming bitter and producing seeds. 
  • Companion Planting – Companion planting allows you to give your basil a great advantage. For example, one older gardener’s tale says that growing basil and tomatoes side-by-side make both taste better. Some people believe it and some don’t. A few good companion plants for your basil if you don’t want to stick it in a traditional herb garden include oregano, tomatoes, lettuce, and peppers. 
  • Fertilize Lightly – Basil is a very quick grower that requires little to no fertilizer applications to stay happy. Too much fertilizer can actually kill your basil’s flavor. If you do want to add it, pick out a liquid fertilizer and add it lightly twice a season for your basil growing inside. If you want to grow basil in a pot, you can add fertilizer at a rate of once every three to four weeks with a very weak, diluted formula. This can compensate for the nutrients you wash away when you water. 
  • Pinch Back the Leaves – Pinch the leaves from the tips of your basil as soon as you see two sets of true leaves on the plant. THis will encourage your basil plant to grow bushy and full over leggy. 
  • Water Regularly – Basil likes to stay moist, and you should give in around an inch of water each week. Water it deeply once a week to keep the roots growing deep and the soil lightly moist. Growing basil in containers will need watering on a more frequent schedule. When you grow it in a container, your goal is to keep the soil from drying out. Water it in the early morning for the best results. 

Frequently Asked Questions

1. How long does it take for basil to grow from seed?

When you start your basil from seed, you’ll typically see germination starting between 7 and 10 days after you plant it. You can usually harvest it within three to four weeks. 

2. Why is your basil plant wilting?

There are a few reasons why your basil is starting to wilt. You should start by checking the soil. Basil likes moist soil, but it shouldn’t be too dry or wet. You want the soil to be damp without dranching it. Also, basil loves warm weather, but the hot midday sun can be too harsh. If you see any wilting happening during the peak hours for your summer temperatures, you should need to add light shade over the plant. 

3. How much sun does basil need to grow?

Ideally, basil needs to have six to eight hours of sunlight every day. Part of knowing how to care for your basil plant is watching the sun patterns in the location where you grow this herb. With a good amount of sunlight, the plant will stay beautiful and big for several months. 

4. Is it better to plant basil indoors or outdoors?

Basil is a very hardy herb that will grow extremely well both inside and outside. As long as you give this plant the proper amount of sunlight and moisture, it can thrive in just about any location. Basil grows very well in containers, both inside and outside, and you can tuck it into your vegetable garden too. Once you know how to correctly grow this herb in a pot, you have endless possibilities.

Mastering how to grow basil indoors is a great skill to learn, and can reap rewards for you for many years to come once you get the hang of it.