How To Grow Basil Indoors: Seed to Harvest in 13 Simple Steps

Basil is a type of herb that is grown once a year and has a pleasant scent and strong taste. It is commonly used for making tea and pesto, as well as enhancing the taste of soups, sauces, and marinades.

The medicinal properties of basil have been known for ages, and the herb has been prescribed to treat a wide range of health conditions ranging from stomach ache and constipation to muscle pain and mood swings.

If you don’t have the space in the garden to grow basil, you can grow it indoors with little hassle.

Supplies Needed

  1. Basil seeds
  2. Medium-sized pot
  3. Spray bottle full of water.
  4. Potting soil
  5. A pair of scissors

1. Seed Selection

One of the best ways to ensure that your basil will grow successfully indoors is to get the seeds from your local nursery. Basil comes in different varieties, and you can find the right variety for your Hardiness Zone in the nursery near you. Buy a pack of 100 basil seeds.

2. Choose the Right Pot

Basil is an annual, so the pot you plant the seeds in is the same one where the plants will spend their short life. Choose a medium-sized pot made of terracotta, plastic, or concrete.

As long as the pot has drainage holes at the bottom, the material won’t matter. Place a few pebbles at the bottom of the pot to prevent the soil from blocking the drainage holes.

3. Mix the Soil

The soil should be quick to drain and rich in nutrients. You can use soil from the garden, or buy potting mix from the local nursery. If the soil is too heavy and doesn’t drain well, mix it with coarse sand or perlite to improve drainage. Add organic materials to give the basil plants a good start. Fill the pot with the potting mix about three quarters full.

4. Plant the Seeds

Spread the seeds on top of the soil. For a medium-sized pot, you can plant between 5 and 7 seeds. Space the seeds evenly to ensure a higher germination success rate. You’ll thin them out later. Cover the seeds with a thin layer of soil. Seeds need light to germinate, so don’t push them into the soil.

5. Water the Soil

Use the spray bottle to get the soil moist. Don’t water the pot until the soil is wet or water flows out of the drainage holes. Basil seeds need the soil to be just moist. Avoid exposing the seeds when you spray them with water. Aim the nozzle at the sides of the pot. If you’re worried that the soil will dry out quickly, cover the pot with plastic after you water it.

6. Keep the Pot in a Sunny Spot

Choose a sunny spot to place the container. It should be a sheltered area that doesn’t get strong winds. The seeds need to get between 6 and 8 hours of direct sunlight every day in order to germinate successfully. Avoid exposing the seeds to trapped heat in a poorly ventilated room where the heat can cause the soil to dry out.

7. Water the Basil Seedlings

After 5 to 10 days the seeds will germinate, and the first leaves will emerge on the seedlings. You need to water the pot at least twice a week to keep the soil moist. Aim for the base of the seedlings to encourage the root ball to grow deeper. Don’t allow more than 1 inch of the top soil to dry out between irrigations. Basil seedlings need a lot of water to grow.

8. Provide Adequate Light

A south- or west-facing window is the right spot to keep the basil pots. You can set up grow lights over the pot or pots to provide adequate light to the young seedlings. If you’re using fluorescent artificial lights, place them at least 1 foot from the top of the basil plants, and turn them on 10 to 12 hours a day.

9. Test the Soil Regularly

Basil thrives in pH levels between neutral and slightly acidic, but the water you use and even the compost and fertilizer can change the chemical structure of the soil, which could impact the growth of the basil. To prevent that from happening, check the soil pH once every 3 to 4 weeks.

10. Provide Airflow

Besides light, basil also needs good airflow around the plant to improve ventilation, harden off the stalks, and prevent fungal infections. Aim a regular fan in the general direction of the basil pots, and turn it on for 1 to 2 hours every day. Keep the air current low.

11. Thin Out the Plants

Once the basil plants have two sets of leaves, it’s time to thin them out. Select the healthiest basil seedlings to keep, and pull out the rest. After thinning, basil seedlings should be between 6 and 12 inches apart. This prevents root competition over resources and provides good air ventilation.

12. Pinch off the Top of the Basil

Basil tends to get leggy as it grows taller. That means the leaves will grow on top of the stalk while the base remains bare. To avoid this, pinch the top of the bail plant once it has developed three true leaf sets. Use a pair of scissors to cut the top of the plant and encourage lateral growth. Prune any weak, damaged, or sick leaves as soon as you see them.

13. Harvesting

Start harvesting basil leaves as soon as you have 4 to 5 mature leaves on the plant. Don’t harvest all the leaves at once since that will impact the growth of the plant. If the plant starts to flower, pinch off the flowers to let the basil focus on developing fresh leaves.

Growing Basil in Pots – 4 Key Tips

  1. Don’t place a tray under the pot. This will cause the soil to stay wet, which leads to root rot.
  2. Don’t plant the basil seeds deep into the soil. Spread them on top, and cover them with a thin layer of soil.
  3. Check the soil pH once every 3 to 4 weeks to make sure the soil acidity is within the recommended ranges of 6.00 to 7.5.
  4. Don’t throw away the basil seedlings you thin out. Replant them in a new pot of their own.

Best Soil for Basil Indoors

Loamy soil is the best type of soil for growing basil indoors. The soil drains quickly but has good retention of moisture. Sandy soil drains moisture too fast for the roots to absorb them. Clayish soil gets waterlogged easily, which causes root rot.

How To Grow Basil Indoors in Water

To grow basil indoors in water, follow these steps.

  1. Cut a 4-inch stem of a healthy basil plant with leaves growing on it.
  2. Remove the leaves from the lower half of the cutting.
  3. Fill a jar with water, and place the cutting in the water so that the leaves remain above the water.
  4. Place the jar on a window sill that gets 6 to 8 hours of sun daily.
  5. The cutting will develop roots within two weeks.
  6. Change the water every 2 to 3 days to prevent mold buildup.
  7. When the roots are 3 to 4 inches long, you can transplant the basil into the garden. 

Conclusion

Basil is an aromatic herb that is easy to grow indoors. Provide loamy soil, regular watering, and 6 to 8 hours of sunlight to keep the basil growing successfully.