Growing Basil for Pesto

, written by Benedict Vanheems gb flag


Basil is the queen of herbs. Nothing comes close to its rich, mouth-filling flavour – it’s packed with the stuff! Tear the leaves up onto a salad and they will give it an instant lift. Pulse it in a blender with pine nuts, hard cheese and olive oil for a sensational homemade pesto. Or layer it with mozzarella and slices of just-ripe tomato for a simple but awesome starter.

The Italians are onto a good thing, with basil varieties such as the classic ‘Genovese’ a staple of real, home cooking. Fragrant, near-glossy dark-green leaves make the best pesto, but look out too for red and crinkle-leaved varieties and the bushy Greek basil, whose tiny leaves pack a tasty punch.

Giant-leaved basils are an extraordinary addition to the Italian kitchen garden, where the outsized leaves are wrapped around fresh mozzarella balls, drizzled with olive oil then served up with crusty bread and, of course, an honest glass of wine. This is epic Italian soul food worthy of serving up anywhere and everywhere!

Basil seedlings on a windowsill

How to Make Proper Pesto

Basil is synonymous with pesto. Commercial pesto takes many, often unconventional forms, with store-bought jars deviating to include imposters such as sun-dried tomatoes and rocket. Proper pesto starts with three core ingredients: basil, cheese and olive oil. What’s added beyond that is a matter of personal taste, with pine nuts and garlic being typical additions. I have made pesto with local hazelnuts and extra virgin rapeseed oil before. It was very tasty indeed, though I suppose it wouldn’t class as pesto to the purists.

The best pesto is made with a pestle and mortar. It takes a little more effort than blitzing everything up in a food processor, but the result is a slightly chunkier finish and none of the sloppy ‘green cream’ you risk from ill-judged blending.

First to go into the mortar is garlic, if using, then nuts and then, one by one while working the pestle quickly, the basil leaves. Next it’s the turn of your cheese (Parmesan or Pecorino typically) and, finally, olive oil, drizzled in until you have the desired consistency. Toasting the nuts beforehand brings out more of their flavour; leave them to cool before using.

Homemade pesto is something else! It’s obviously delicious folded into pasta, but you could try it as the basis for a salad dressing, dabbed onto pizza, or stirred through thick, creamy pulses such as butter or lima beans.

Basil pesto

How to Sow Basil

If you want to make pesto, you’ll need lots of generous handfuls of basil. That means more than a single stingy pot on the windowsill; grow it big time and reap the rewards!

Frost-tender basil is best started off under cover earlier on in the season. My preferred method is to sow a pinch of the tiny seeds thinly into pots of multipurpose compost before covering with the merest suggestion of compost – just enough for the seeds to disappear from view. The top of the pot then gets a cover of cling-film or a clear, plastic bag held in place with an elastic band. This creates the humid environment the germinating seeds love. Keep pots on a warm windowsill.

Remove the covers once the seedlings emerge. Then three or four weeks later it’s time to prick them out (when seedlings are teased apart and replanted), very carefully, into their own mini pots. If the thought of fumbling with tiny seedlings doesn’t appeal, leave the seedlings to grow on a little longer then carefully tear apart the rootball into four and replant small clusters of young plants straight into the ground or larger pots.

Once the soil is warm enough (usually by late spring), seeds may be sown directly outside, or into a cold frame or greenhouse in cooler areas.

Purple basil

Grow Happy Basil

Basil loves the warmth, so clearly a sunny and sheltered spot is what they need. Plant your young plants about 20cm (8in) apart in both directions. In very hot, sunny climates they’ll appreciate a little shade as they find their feet, so pop upturned pots over the seedlings for a few days until they are settled in.

Basil that’s grown on in larger pots on the patio will respond to regular feeding with a general-purpose organic liquid feed. And all plants will appreciate refreshment in hot, dry weather. Once the plants reach about 20cm (8in) tall, cut them back by half. This may seem drastic, but the plants will respond by branching out to produce lots more foliage. The prunings, of course, are your first delicious harvest.

The plants will inevitably want to flower. You can pinch off the flower spikes to prolong the useful life of the plant. Or let them burst into bloom and attract beneficial insects such as butterflies.

With several plants on the go you can be picking a few leaves from each most days, ensuring you’re living the Italian dream with this most flavoursome of herbs.

Plants Related to this Article

Bugs, Beneficial Insects and Plant Diseases

< All Guides

Garden Planning Apps

If you need help designing your vegetable garden, try our Vegetable Garden Planner.
Garden Planning Apps and Software

Vegetable Garden Pest Warnings

Want to Receive Alerts When Pests are Heading Your Way?

If you've seen any pests or beneficial insects in your garden in the past few days please report them to The Big Bug Hunt and help create a warning system to alert you when bugs are heading your way.

Show Comments


"What a strange way to introduce a reasonably knowledgable article on basil ... with a photo of baby spinach leaves! suggest you find another stock photo for the header. (The photo of the dark purple leafed basil doesn't look like basil either!)"
Angela Marshall on Tuesday 13 June 2017
"Hi Angela. You're very eagle eyed! I'm not sure how the picture of spinach snuck its way in there, but we've now replaced it. Thanks for pointing this out. :-)"
Ben Vanheems on Tuesday 13 June 2017
"Hey - prompt and honest! Well done. Both photos are now of genuine basil which means I now trust the information a lot more! Thank you."
Angela Marshall on Tuesday 13 June 2017
" Thanks Angela, we like to be kept on our toes! Hope you have good success with basil and cook up a delicious pesto based delight."
Ben Vanheems on Tuesday 13 June 2017
"Do you have to grow new plants every year ?"
Derrick on Sunday 18 June 2017
"Hi Derrick. Yes, you do. Basil are annuals, which means that once they have flowered they die. You will probably need to grow a few plants every year, as they are unlikely to last more than a few months with regular picking - and then they will inevitably flower. So sow a pot or two every month or so throughout the growing season. It's an incredible herb and well worth the little effort involved. Enjoy!"
Ben Vanheems on Monday 19 June 2017
"oh, well I'm off to get some seeds, not sure if June is an ideal time to plant them, but got nothing to lose"
Derrick on Monday 19 June 2017
"Why does the article make no mention of basil being an annual, meaning it will die and must be replanted yearly?"
Chris on Saturday 14 July 2018
"Yes, you're right Chris. Basil does need re-sowing quite often. Even with it being an annual you'll get the best harvests by sowing new pots every three or four weeks to ensure a continuous supply of luscious leaves at their peek of performance."
Ben Vanheems on Monday 16 July 2018

Add a Comment

Add your own thoughts on the subject of this article:
(If you have difficulty using this form, please use our Contact Form to send us your comment, along with the title of this article.)

(We won't display this on the website or use it for marketing)


(Please enter the code above to help prevent spam on this article)

By clicking 'Add Comment' you agree to our Terms and Conditions