Never Buy Basil Again! How to Grow Basil from Seed to Harvest

Fresh basil is an essential ingredient for so many dishes. It might seem easier to pick up fresh basil at the grocery store, but if you love fresh basil pesto, you’ll be amazed at how much money you can save and how easy it is to grow at home. We’ll show you how easy it is to grow basil from seed indoors and out for a continuous supply of this fresh and flavorful ingredient.

If you’re like Patty and never want to be out of basil, growing your own from seed is the way to go. Basil is a warm-weather plant and thrives in the summer. It can also be grown indoors with adequate light in the winter.

Growing basil from seed gives you an opportunity to try all kinds of basil, each with its own distinct flavor. You can use any variety of basil to make an easy pesto sauce.

Basil can be direct sown outdoors when the soil has warmed up to 70ºF. You can also start seeds indoors to transplant when temperatures are warm enough.

Since basil grows quickly and bolts under the stress of drought and heat, consider sowing seeds every month to make sure you have plants at different growth stages.

Basil is easy to start from seed with these germination tips. 

• You can sow seeds 6 to 8 weeks before your last frost date or any time, really.

• Needs heat - use a heat mat indoors to keep the soil temperature between 70-80ºF for germination.

• Keep the soil moist - a humidity dome indoors can help prevent the seeds from drying out. (Once the seeds have sprouted, you no longer need a cover.

Basil plants can be transplanted outdoors when they have about three sets of true leaves and a healthy root system. You also want to wait until the weather is warm and all danger of frost has passed.

Take time to harden off basil seedlings before placing them outdoors. They aren’t used to the harsh outdoor conditions and can wilt in full sunlight outdoors. Sara, our head gardener at Sow Right Seeds, takes time to acclimate these tender herbs. Over the course of a week, she keeps them in the shade and out of the wind. Then, she slowly increases their time in direct sun.

Before transplanting basil outdoors, nighttime temperatures should not be colder than 50ºF.

Space basil plants 15 inches apart to give them adequate room to grow. Basil plants will easily grow 10-16 inches wide and 24-30 inches high in a warm and sunny spot.

You can plant basil plants slightly deeper than the level it was growing.

Patty and Sara usually transplant the basil in mid to late May when the weather is warm.

Patty recommends pinching off the top of the plant early when it is about 4 to 6 inches tall to promote bushier growth. This way, the plant won’t have just one tall stem.

Basil is an easy plant to grow. It makes an excellent companion plant to tomatoes. I like to put basil in between my tomato plants. Basil loves warm weather, so wait to grow it outside until all chance of frost has passed. And if you are growing it in containers, bring it indoors before the first fall frost.

Basil likes full sun. Those green leaves will be healthy with at least 6 to 8 hours of sunlight daily. Dappled shade can help prevent bolting in hotter climates. I like putting basil with my tomato plants. The basil plants don’t grow as big, but they don’t flower as soon.

Grow basil plants in nutrient-rich soil that is loamy and drains well. Add some well-rotted compost before transplanting basil plants.

When the top 1 inch of soil is dry, it's time to water. Basil plants prefer consistently moist soil without the roots being waterlogged. Outdoor containers may dry out more quickly, so water as frequently as needed.

Basil plants are quick-growing and usually don’t need additional fertilizer. If you have poor soil, the plants can benefit from a balanced fertilizer or one with a little extra nitrogen for leaf growth. Use fertilizer at half-strength.

If you’re trying to figure out where to place your basil plants in the garden, it’s good to know that basil makes an excellent companion plant. The easiest way to choose companion plants is to look for plants with the same watering and soil needs. Basil is a natural addition to a flower bed since so many flowers have the same requirements. Peppers are one vegetable that pairs well. Sara has planted a whole raised bed of different basil varieties. I plant basil in my herb garden next to the oregano, and I also tuck it in with the tomatoes. The basil plants grown with the tomatoes don’t grow as big, but they don’t go to seed as quickly. Sage and thyme don’t like such moist soil, so they’ll grow best in an area separated from basil.

Two plants to avoid next to basil are fennel and cucumbers. Fennel isn’t a great companion and hinders the growth of many plants. Some gardeners avoid planting basil next to cucumbers because it affects the flavor of their cucumbers.

Harvesting and pruning frequently will help keep your basil plant from going to seed.

You can start harvesting basil leaves once the plant has 6 to 8 pairs of leaves. You never want to take off more than 2/3 of the plant to keep it growing and healthy.

Cut the tops at a leaf node. From this spot, two new branches will grow. Cut down far enough where there are two stems.

Always remove the flower stems as soon as they appear.

Basil is like a cut-and-come flower. The more you cut, the more it will grow.

If you aren’t going to use it right away, you can place cut stems of basil in a glass of water.

Some common pests and diseases are:

Root rot - Root rot will make a basil plant turn yellow and quickly die. Ensure plants have well-draining soil so the roots aren’t waterlogged.

Fusarium wilt - Spacing plants far enough apart for good airflow can help prevent fungus problems.

Aphids - These tiny insects are everywhere. Use natural methods to control them so that your basil remains edible.

Spider mites - If you see webs over the leaves, you may have spider mites. The mites are hard to see, but the damage is visible where they suck out the plant juices. 

Slugs - Slugs are always looking for tender greens. Use these methods to keep slugs from ruining your basil plants.

Japanese Beetles - Patty likes to keep at least one basil plant close to the kitchen door so she can pick off the Japanese beetles faster than they can eat the basil.

It’s easy and rewarding to grow basil indoors so that you can appreciate the fresh flavor at any time of year. The main requirement is to get enough light to grow a healthy supply of leaves. If you have a sunny south-facing window, it may provide enough light. Your indoor plants won’t be as big and bushy as outdoors, but a grow light can give adequate light for healthy growth.

When growing basil indoors, you also want to make sure that the soil drains well. It’s easy to kill a basil plant from overwatering. Don’t let the roots stay too wet.

Have you ever considered growing basil for flower arrangements? The green and purple leaves are fragrant and make a beautiful filler. When the basil plants flower, they add additional texture and color to bouquets. Thai, Purple Ruffles, and Opal basil are some unique varieties with a purple hue in their leaves and flowers.

Instead of panicking when your basil starts flowering, cut it and add it to your indoor floral arrangements.

If you love the taste of fresh basil pesto, you’ll want to grow enough basil plants to keep up with demand. Start growing basil from seed indoors or outside and see how easy it is. You’ll never have to buy basil again.