top view of growing basil

How to Grow Basil

Basil is a versatile annual herb used in salads, pesto, pasta sauces, pizzas, Thai curries and so much more. Sweet basil is the most common one but when sowing from seed there are lots of exciting varieties with different flavours, shapes, colours and textures. 


As basil likes to grow in well-drained, fertile soil, in a warm and sheltered position – it is perfect to grow in your S-Series Mini Greenhouse. For the best results grow basil in a pot, but a tray can work too. 

Fill a pot with peat-free multi-purpose compost, water it and then scatter the seeds on top. Do not sow too many as they tend to have a good germination rate. Do not cover the seeds with compost but if you have some vermiculite you can sprinkle that on top. Press down the seeds slightly to make sure that they have good contact with the soil. Water again by misting and put a plastic dome or cling film on top. Make sure that it has air holes for ventilation. Keep the soil evenly moist until the seeds germinate because if they dry out they will most probably not germinate at all. Having said that, be careful not to overwater!

Basil will germinate at 15-29°C, but as a general rule you want to aim for the higher range as the germination will be both quicker and more successful. At high temperatures they can germinate within a couple of days! 12-16hrs of light is preferred once they germinate.

Plant care 

After germination, remove the plastic from the top and grow on – ideally at 20-25°C. When the seedlings are big enough to handle, pot them on into individual small pots filled with peat-free compost. Every time roots show through the drainage holes at the bottom move it into a slightly bigger pot till you reach a 20cm one. 

You can keep the pot in your S-Series or put it outside in early summer after the last frost. To acclimatise the plants to outdoor conditions, lift them outside in a sheltered, lightly shaded spot during the day, and put them back in at night. Do this for about two weeks before leaving them out all the time. Gradually increase the time outside. However, when growing Basil outside they must be protected from wind and frost so choose a warm and sheltered spot. 

It’s worth noting that Basil dislikes having wet roots overnight, so water in the morning if possible and avoid splashing the leaves. Basil can also be a bit sensitive to strong direct midday sun. When growing in pots, it is important to keep on feeding the plants throughout the growing season!


Harvest regularly by picking the leaves and tops to keep the plant bushy and productive. Remove any flowers that s

Watch out! 

Slugs and snails like to munch on the leaves, so you should protect the plants by keeping them in your Sprout or plant them out when they’re a bit bigger. Whitefly and red spider mites can attack, but a strong and healthy plant can usually resist these attacks quite well. Spray the undersides of the leaves thoroughly with an organic insecticidal soap to control large attacks. Greenflies can also be a problem and are best treated by being removed using your finger and thumb to squash them.

Pro Tip

Basil can be stored in the fridge for a few days, but do not wash the leaves until you’re ready to use them as they’ll turn slimy. Another great way to store it is to stand cut stems in a glass of water until you’re ready to use them. If you leave them in the water for a while they will develop new roots and you have a new plant!

Nerdy facts

The botanical name of basil is Ocimum basilicum and has traditionally been included in the treatment of colds and inflammation. 

Recommended Varieties

Here are three great varieties but there are so many more fantastic varieties to choose from! 

‘Genovese’ is the most popular Basil with bright large green leaves on multi-branched stems. Ideal for pesto, and perfect in pasta sauces and salads. 

‘Lemon’ has a slight lemon flavour that is particularly good with fish or chicken and in South-East Asian dishes.

‘Purple Ruffles’ is one of the best purple varieties with ruffle-edged leaves and pink flowers.