If herbs were a royal family, rather than (a) savoury or fragrant plants used for flavouring food, or (b) characters in an early 70s TV programme for kids then, in my opinion, Basil (Ocimum Basilicum) would be king.
But sometimes Basil doesn’t get treated like a king, and we don’t get to see and taste it in its full regal splendour.
In this video, with a couple of simple techniques, I show you how to grow basil in a way that get the best out of your Basil plants.
How to grow Basil – Step by Step
In summary here is how to grow basil get the very best harvest from you plants:
- Grow individual plants
Basil seeds are small, so more often than not we sow several together in pots or seed trays. This is fine, but to get good healthy, flavoursome plants, you need to prick out the individual seedlings and grown them on in separate pots.
- Pinch out the growing points
Once you have individual plants growing on strongly, you need to help them thicken up by pinching out the top growing point of the plants. This then stimulates the growing points between the leaf buds lower down the plant so that it develops side shoots. As the side shoots grow on, you can apply the same technique to the lead growing point of each shoot, stimulating more growth and thus creating a leafy, bush plant. See the Botany section below for an explanation as to why this works.
- Grow on in containers
In most places, Basil plants do best in containers. If you give them the right conditions (see the next step), you may need to pot them on a couple of times during the growing season as they increase in size.
- Give them fertile, moist, well-drained soil
Keep the growing media moist, without letting it get waterlogged, and give the plants plenty of warmth and light. A greenhouse or sunny windowsill is ideal in northern latitudes, although it is best to avoid direct, hot sun for prolonged periods (especially around midday), or they may get scorched.
- Sow successionally
Sow seeds every two three weeks in spring and early summer to ensure a plentiful supply of Basil right into late autumn. Bring the plants in to a warm environment as temperatures and light levels drop in Autumn.
Basil are half-hardy annuals. This means they are frost tender and will grow from seed to flower (and seed setting) in one year.
So what is happening, botanically, when we pinch out the growing shoots of the plants?
In common with most plants, Basil has dormant growing points called axillary (or lateral) buds, in between the stem and leaves of the plants (the leaf axil). These buds are embryonic shoots that have the potential for growth.
When the lead growing point is removed, the hormone auxin is diverted to the axillary buds and stimulates them into growth. Typically there are axillary buds on either side of the main stem, thus the result is that there are two growing shoots instead of one. This is how they plant becomes bushier.
Pinching out the growing points also prolongs the productive life of the plant. Because Basil is an annual, it is in a hurry to flower and set seed. By pinching out the tip of a stem on our Basil plants, we prevent the plant from flowering from that stem, so it keeps on growing new shoots in an effort to flower from those stems.
This is comparable to when we deadhead flowers. In that case, we prevent the plant from setting seed so that it flowers more. With plants that we value for their leaves (like Basil), we prevent them flowering so that they produce more leafy growth.
It is also worth preventing flowering because once the plant has flowered, it produces less oils and the flavour of the leaves is impaired.
If you give Basil room to grow on its own, whilst pinching out the top growth and keeping it warm, watered and fed, you’ll get wonderful aromatic leave all summer long.
I recently harvested several pots of Basil and made an amazing tasting Pesto sauce and I can tell you that the effort in caring for the plants was well worth it for the taste they gave us.