You only need one healthy basil plant to become self-sufficient. Read on, and I will show you how to grow a basil plant from seed and then use that one plant to grow and harvest as much basil as you want.
Basil or sweet basil (Ocimum basilicum) has large aromatic leaves and is one of the more popular herbs to grow from seed among home gardeners.
You may know this herb as Italian basil or "Genovese basil" - one of many popular cultivars or varieties of this popular herb.
Today, we will show you how to grow basil from seed in a pot or container at home.
- Growing basil from seeds in 5 simple steps
- Harvesting basil plants
- Can I direct sow basil seeds?
- 3 common mistakes in growing basil from seed
- Frequently asked questions
Growing basil from seeds in 5 simple steps
Basil is a great first herb to grow from seed. To get started, you will need the following:
- seed tray, pot, or small container with a cover
- potting soil mix (or a soil-less medium like coconut coir)
- good quality basil seeds
Here are five tried and tested steps to start growing basil from seeds.
1: Choose a pot or container
We use seed trays or small starter pots. When using starter pots, I prefer recycled plastic pots (7 centimeters / 3 inches) that help maintain an even level of soil moisture.
A seed tray will usually come with a plastic cover or dome. Starter pots can be covered with plastic wrap.
There is no real advantage to planting basil in larger-sized grow bags, pots, or containers. Seeds should be planted shallow and it is easier to control and maintain moist soil in smaller-sized pots and containers.
2: Choose your soil
I use a mix of equal parts cactus and regular potting soil mix. But you can use any quality potting mix that drains well.
Why do we use two different types of soil? We will plant the seeds in the cactus soil mix. The cactus soil mix holds no added nutrition and has a looser structure, allowing the seeds to germinate quickly.
But when the seeds have germinated, the young seedlings develop deeper roots and are now met by a slightly more fertile potting soil mix.
This method works well for me, and I believe it helps the seedlings create more robust and compact root systems.
Please note that both types of soil are lean potting soil mixes. Seeds do not need extra nutrition to germinate. The seeds themselves hold all the energy needed for the seeds to germinate and sprout first leaves or cotyledons. Overly fertilized soil will burn the fresh and delicate new roots when your seeds germinate.
3: Sow basil seeds
Place or plant basil seeds gently across the surface of your potting soil. Sprinkle the seeds across the soil and make sure to space the seeds 1 cm (1/4 inch) apart.
Next, press down on the seeds gently. By pressing on the seeds, we remove air pockets and make sure the seeds have contact with the soil. Check your finger tops to ensure the seeds do not stick to your fingertips.
Cover your seeds with a fine layer of soil or vermiculite to help retain moisture.
To avoid displacing seeds when watering, mist the soil surface using a spray bottle.
Next, cover the pot with clear plastic. Make holes in the plastic to ensure good air circulation. Fresh air is essential, and you do not want to seal the pot hermetically.
If you see excessive condensation inside your plastic cover, you must improve airflow and circulation.
Should you soak basil seeds before planting? You could as soaking basil seeds will help the seeds germinate faster. I do however not pre-soak basil seeds as the gemination rate is good and I find it harder to work with pre-soaked smaller seeds sticking to my fingers.
Make an effort to avoid placing all the seeds in a clump. As the seeds are on the smaller side, I find it helps when working with 3-5 seeds at a time.
Planting seeds too close together will force you to thin the seedlings later. Keep in mind that basil often has a germination rate above 80%, and each seed has the potential to develop into a mature plant.
Seeds will germinate in 4-7 days, depending on factors such as soil temperature and light.
4: Watering the young basil plants
Remove the plastic cover and place pots in a location with good light when seeds germinate and sprout.
Place the pot in a warm location (20 degrees C / 70 degrees F) with full sun, although out of direct sunlight.
Bottom water your seedlings by placing pots in a water bath. Bottom watering is excellent when working with many pots. Simply place the pots in a container with water. Now let the soil suck up the water through the drainage holes.
As you can see in the photo, the light soil will go darker in color as it absorbs water from the container.
When the surface of the potting soil is dark and wet, remove the pot and put it on a surface to drain any excess.
Again, you are looking for moist but not wet soil. And draining the pot ensures the correct level of moisture.
5: Transplant 3-5 seedlings into a larger pot
When the seedlings are large enough to handle (ca 10 cm / 4 inches), we repot the basil plants to a bigger pot.
When starting seeds in smaller pots, transplant 3-5 seedlings into larger pots with fertile well-draining soil. Or transplant basil seedlings to planting boxes or your outdoor herb garden.
If you grow basil in rows, keep the rows approximately 30 cm (12 inches) apart to promote healthy growth.
When plants reach maturity, start feeding them at least every 2-4 weeks. Use organic fertilizer, and always begin by giving half the recommended dosage.
Harvesting basil plants
The basil plant takes approximately 50 days to grow from seed to mature and reaches a height of about 25 cm (10 inches).
You can – and should – harvest basil leaves continually throughout the plant’s life.
Regular harvesting, pruning, and pinching tops promote the growth of bushier and more productive plants. And remember to feed your plants with fertilizer (organic) if you expect them to keep producing new leaves.
Topping basil is easy. Count the pairs of leaves from the top of the stem. Now pinch the stem just above the third pair of leaves (counting from the top).
The tops you pinch can, of course, be eaten. Or use the tops as stem cuttings to grow more basil plants.
Can I direct sow basil seeds?
You can direct sow basil outdoors as soon as you have passed the last expected frost date and the minimum temperature is above 10 degrees Celsius (50 degrees Fahrenheit).
But keep in mind that basil does not like wind or cold weather. And to be honest, as basil is one of the easiest herbs to grow indoors, I do prefer growing basil indoors.
I start basil from seed indoors and keep my basil plants in pots for their entire lifespan.
I do, sometimes, move the pots outdoors. But generally speaking, the plants live somewhat sheltered in their pots. This also means that my growing season gets extended beyond spring and summer.
And using a grow light I can and do grow basil indoors year-round.
Maybe this is why I have never had serious problems with pests like aphids, fungi, or Japanese Beetles. Aphids are common pests when growing basil. A water-based Neem oil spray solution can help keep pests in check.
3 common mistakes in growing basil from seed
I have been called on by friends and family to rescue basil plants on more than one occasion. It is not that it is challenging to grow basil from seed. Instead, beginners tend to care too much and almost try too hard.
I can say with authority that overwatering kills at least as many plants as underwatering. Mold growth on soil and yellowing basil leaves are indicators that you may be overwatering your basil plant.
Here are 3 common mistakes I see home gardeners make.
1. Warm does not mean hot
Do not confuse full sun with direct sun all day log. Basil plants like it warm (20 degrees Celsius / 70 degrees Fahrenheit) but not too hot. Protect your plants from the direct sun, especially during the hottest times of the day.
2. The basil plant does not like wind
Basil can be grown outdoors, but it is quite a tender annual herb. Protect your plant from wind by choosing a protected spot in your garden, or use companion planting to shield and protect your basil.
3. Overwatering your basil
Seeds need moisture as well as oxygen to germinate. If you overwater, you will drown your seeds, and they will rot, and you will never see any growth.
Also, basil seedlings will not survive if the root system is sat in constant wet. Your plant will suffer root rot, and roots will start to smell and turn dark and slimy.
This is why it is essential to use well-draining soil. You want the soil to be moist but never soaking wet.
Keeping the basil plants in pots gives me control. I move my plants to where they want to be given the external conditions. And this works for me. But you can of course plant your basil plants outdoors in your herb or vegetable garden should you prefer.
Frequently asked questions
Which basil varieties do you recommend?
We grow sweet basil (including the “Genovese basil” cultivar), Thai basil, lemon basil, and cinnamon basil every year.
This mix gives us a variety of flavor profiles and textures.
Why do you use plastic pots to start basil from seeds?
I use plastic starter pots as they are inexpensive and help me to control soil moisture.
But feel free to use peat pots, terracotta pots, or any other pot apart from pots made from metal as they can get too hot.
Will basil survive frost and cold weather?
Basil does not like cold weather or frost. If transplanting basil outdoors, ensure you are past the last expected frost date with a minimum temperature above 10 degrees Celsius (50 degrees Fahrenheit).
Is it challenging to grow basil from seed?
Growing basil from seed is relatively straightforward and is ideally suited for home gardeners at any level, including beginners (and children).