How to Grow Basil from Seed in 7 Simple Steps
Are you thinking about planting basil in your garden this season? Basil is often propagated from cuttings, but can also be easily grown from seed. In this article, organic farmer and gardening expert Jenna Rich shares how to grow basil from seed in just a few simple steps.
Spring is quickly approaching which means it’s time to plan your summer garden. You might be someone who opts to purchase plants from your local farmer or gardening center before popping them into the ground. While this is a great option, I urge you to try starting your own plants from seed and basil is a great one to start with.
Basil is great for beginner gardeners because it generally has high germination rates, and you can fit lots of seeds in a small amount of space. Plus, it’s a great addition to every garden.
The hardest part about the entire process of starting basil from seed is waiting until it’s mature enough to start harvesting and enjoying! Keep following along for 7 easy steps to start basil from seed.
Step 1: Gather Seeds & Supplies
Start by purchasing your seeds from a reputable source. Almost every seed company offers many varieties of basil. You can find varieties that range from traditional Genovese, to Thai, to purple to lemon-flavored basil.
When stored properly, basil seeds can last many years so choose a size package of seeds that makes sense for your growing habits.
To sow seeds, you will need the following:
- High-quality seed starting mix
- Strong cell trays or small pots
- Optional trays
- Access to water
- A sunny place or a setup with artificial lighting
- Optional heat mat
A heat mat is helpful but not required. Basil is a heat-loving and tropical crop so providing heat to assist with germination may help you get a higher germination rate.
With ideal conditions (75º-85º and evenly moist), basil seeds should germinate in about 5-7 days. If you do choose to use a heat mat, be sure to keep a close watch on the moisture level of the soil to ensure it does not dry out.
You should start basil seeds indoors about 6-8 weeks before your last frost date if you want your plants to be ready to plant out in the spring. Many herbs tend to take a long time to grow large enough to harden off and transplant and basil is no exception.
Step 2: Prepare Your Cell Trays
Before getting started, add water to your seed starting mix so that the consistency is damp.
Pro tip: Take a handful of the soil and squeeze it. If it crumbles and falls from your hand, it needs more water. If water is running out of your hand and the soil, add a bit more soil, it likely contains too much moisture.
Once you are happy with the consistency, fill your cell trays or pots to the top with soil. Give a quick knock on the countertop to gently tamp down the soil. Then make a small divot with a small tool or just the tip of your finger to prepare the soil for seeds.
Step 3: Sow Seeds
Add 2-3 seeds to each cell or pot. Cover loosely with more soil and then tamp down the tray again. This ensures good seed-to-soil contact which is crucial for good germination. The seeds need room to breathe so take care not to pack them in too tightly.
Pro Tip: A general rule of thumb is that a seed should only be buried twice the depth of its width. Since basil seeds are very small, the divot does not need to be deep. If seeds are buried too deep, they will not have enough stored energy to germinate or break the soil surface. If you have trouble managing smaller seeds or are completing this task with children, many companies offer them in a pelleted version which will help with this.
Now place your trays on a countertop in a warm spot or a heat mat and set the temperature according to the back of the seed packet.
Step 4: Keep Moisture and Heat Consistent
The soil should remain damp as you wait for seeds to germinate. You can use a simple spray bottle filled with clean water or if you are using a hose in an outdoor area, you can use a light mister attachment for your hose.
Be gentle when watering so the seeds stay in place under the soil. You don’t want to blast them with an aggressive water stream and risk them flying out of the cells.
Alternatively, you can bottom water. Simply place your cell tray into a shallower tray and add about a half inch or more of water. The soil in each cell will intake water from the bottom tray. Add more if the tops of the cells still look dry when all the water is gone. If water remains in the bottom tray after a few minutes, simply dump it out.
Depending on where your trays are and how warm it is, watering should happen about 1-5x a day when seeds are working on germinating.
Step 5: Provide Adequate Light
After about 5-7 days, you should see germination. When about half of your cells have sprouted, you should provide them with light. If using artificial light, position the seedlings 2-3 inches from the light.
However, if the light is much further away, your seedlings will need to stretch to get what they need, becoming leggy and weak.
If you are using natural light, be sure to place your trays in a place they can receive direct sunlight such as a south-facing window or in a sunroom. If you opted to use a heat mat to aid with germination, you can remove that at this time.
Step 6: Thin, Harden Off, and Transplant
When seedlings have their first set of true leaves, choose the healthiest looking one and snip out the rest with small scissors or a quick pinch with your fingernails. Allow seedlings to continue to grow under light for several weeks.
When plants have about 6 sets of true leaves, pinching back is recommended. This means just pinching off the main stem above the first set of true leaves (not cotyledons). Pinching back will encourage your plant to send out more branches and bush out.
About 1-2 weeks before you plan to plant your basil outdoors, whether in the ground or in a grow bag or pot, you should harden them off by exposing them to outdoor temperatures, direct sunlight, rain, and cooler nighttime temperatures.
This will help with any potential transplant shock. Keep in mind that basil is extremely cold and frost intolerant so keep your eye on overnight lows when completing this step.
Once they are properly hardened off, plants are ready to transplant. Basil plants can be planted 6-12 inches apart, depending on the growing nature of the variety you chose.
To further decrease the chance of transplant shock, you can cover them at night with a light frost blanket as they acclimate to their new home. Be sure to consistently water as well. Mulching will help hold in moisture and heat so consider this if you live in a cooler region.
Step 7: Harvest, Prune, and Enjoy!
Develop a harvest and prune schedule. Keeping up with regular trimming will encourage your plants to grow. Your basil plants will continue to grow up and out as long as you continue to prune.
If pruning fails to happen, the plant will eventually go into reproduction mode and drop seeds. Although any basil left on the plant is still edible, it might have become slightly bitter.
Pro tip: Going to seed will happen quicker when plants are under stress. Be sure to water regularly and keep a close eye on your plants when conditions are stressful such as drought or extreme cold.
What type of basil should I grow?
The type of basil you select for your garden depends on what you plan to use it for. Below I have listed a few popular uses for basil and suggestions for things basil is commonly used for. There are so many options!
The classic Italian Genovese varieties are best suited for this delicious sauce.
Fish dishes and salads:
Get creative with a lemon or lime variety such as “Mrs. Meyers’ Lemon” or “Lime”.
Homegrown dried tea or homemade essential oil:
Sweet and spicy holy basil such as “Kapoor Tulsi” will be great for this.
Where should basil plants go in my garden?
Try growing basil alongside tomatoes or peppers. Some say the flavor of these crops improves when grown as companions. I can’t say they do for sure, but it’s worth a shot!
You can also plant lots of basil together in a large patch. This will not only serve as a great pollinator patch, but it will also smell fantastic as you harvest and brush past it.
Pro tip: Try growing citrus basil in large clumps and brush it around every so often, especially before hosting a backyard gathering. The aroma will serve as a mosquito repellent!
How long will my basil plant live?
If you keep your basil plant pruned and it remains disease-free, there is no reason it won’t last all the way until the first frost, providing you with fresh basil for many months.
It is also possible, in certain climates, to transplant your basil into a large pot and bring it indoors for the winter. If this is something you want to consider trying, I would advise you to plant it in a pot from the get-go for better results.
If the plant doesn’t do well indoors or peters out by the spring, take a cutting, and place it in water for a few weeks until it sends out fresh roots. Then pot it up in fresh soil come spring and voila, you have a headstart on the basil season! Keep in mind, you can take several cuttings throughout the winter.
How can I get my basil plant to produce more?
The more you harvest and prune your basil plant, the more it will produce for you. Pruning encourages more growth so if you cut it at the main stem at least once every 1-2 weeks, it will bush out and continue to grow new leaves. Even if you don’t have an immediate use for basil, keep up with keeping your plants pruned so they will continue to grow.
Pro tip: Toss the clippings into a pitcher of lemon water for a refreshing summer drink.
If you suddenly find yourself with basil in excess, grab a hefty handful and display the stems in a vase for a rustic, fragrant bouquet.
What type of fertilizer does basil need?
Basil does not need much in terms of fertilizer, although it can benefit from a fish emulsion later in the season to hold it over until the first frost. It is not what we call a heavy feeder, but you should plant it somewhere with well-draining, and highly composted soil for best success.