(And how to harvest and preserve it too)
Basil looking lush and ready for it's first harvest Two rows of Basil beside French beans - split supermarket pots on left, module sown on right
Basil looking lush and ready for it's first harvest Two rows of Basil beside French beans - split supermarket pots on left, module sown on right
Basil is possibly the one herb more than any other that most people want to grow, but many find it difficult. It's really not - when you understand it! Basil is a sensitive soul. Like most of us - all it needs is a little warmth, TLC and understanding - and then it will repay you in spades! It's always been one of my most important summer tunnel crops - I freeze masses of it every year which lasts us right through until the next year's starts to crop. It's a herb with such a 'feelgood factor'. We love to use it in pesto sauce for pasta and for pizzas, or for tomato sauces made from our frozen homegrown tomatoes, in herb oils for salads etc throughout the winter, or even in desserts, bread & cakes! It's sacred and revered in many cultures as a health-promoting with antibiotic and antiviral properties. I'm positive it keeps winter colds away, particularly combined with the amount of garlic I use in pesto! But even if it doesn't - it tastes fabulous and is such an aromatic, mood-lifting reminder of radiant summer sunshine - even in the greyest depths of winter!  
 
As with all crops, organically grown basil will be naturally far higher in good phytonutrients than non-organic. A Newcastle University study published in July 2014 found that organic crops were an average of 69% higher in these health-promoting natural plant compounds, and concluded that eating organic fruit and veg was actually equivalent to eating an extra 1-2 portions of them a day! So it's medicine really - of the most delicious and irresistible kind!
.
I was one of the first certified commercial organic growers in Ireland over 30 years ago and I used to grow a whole tunnel full of basil every year. Basil has a wonderful aroma - but believe me - by the time you've got half-way through picking a whole tunnel full - the scent of it is pungent and extremely nauseating! I supplied the Dublin food Co-op back in those days, a few shops and I also had my weekly organic box delivery scheme in Dublin. It was always the most popular herb I grew - even then I never had enough of it to go round and had a waiting list!  Basil was rarely if ever available in supermarkets then, particularly if grown organically - and organic still isn't. Even now, some of my early customers call me every summer to see if I might possibly have a surplus - although I grow just for ourselves now and no longer sell any produce. A couple of months ago, after one of our monthly 'From Tunnel to Table' radio features - Late Lunch Show presenter Gerry Kelly, who is also a keen gardener, asked me how to split up supermarket basil, after seeing some which I'd done in pots here. Growing supermarket-bought basil is something that I've been asked about a great deal over the years when giving talks on organic gardening, so I thought it was time I gave it an article all to itself. It's such a wonderful plant it certainly deserves the five star treatment! 
 
Commercial organic growers are of course never allowed to use any non-organic basil or any other plants to grow on for producing organic crops - they must not even have non-organic plants on their holding. The rules are very strict - I know that as I was one of the people who helped to formulate and put in place the Irish Organic Standards back in the mid 1980's. Under the terms of their licence, growers must raise all their own plants from organic seed. When I eventually gave up commercial growing though, I was able to have a bit more fun with my gardening - experimenting with various methods of getting the very earliest crops of many of my favourites. As a consequence - I developed this method of growing the very earliest basil from those pots you can buy in some supermarkets. The little bit of non-organic compost they will have been raised in is soon remediated by potting them on into a good certified organic one - so the tiny amount of fertiliser that may be in the small supermarket pot doesn't bother me too much. The same goes for any possible - but unlikely traces of anything else - one has to be pragmatic here and a healthy, living organic soil can actually deal with a certain amount of non-organic material! Basil also grows so fast in the warm summer weather that it very soon outgrows any leafy area that may have possible small residues once it's being grown organically  It's much more energy-efficient to raise basil plants this way early in the year too. Home gardeners could never afford the winter heat and vital bright light that commercial herb producers use to get really early crops. It can help to give you a head start on the season - which needs to be as long as possible here for the amount of basil we use all year round! 
 
There's still time to use this method now even in July to get a really good crop before autumn weather puts a dampener on them. In fact it's a great way to grow a large amount of basil very quickly and cheaply at any time of year - as it skips about 4-6 weeks of growing time, particularly in early spring. It's also good for people who may find growing from seed a bit of a challenge. It's generally Sweet Genovese Basil that you see on sale in supermarkets - and I think it's the very best one for the classic Pesto Genovese. For the more unusual kinds of basil like the Giant Red Lettuce Leaved one you can see below though - you will still have to rely on specialist herb nurseries for plants, or grow your own plants from seed.
 
 
Buying pots of Basil from the supermarket for splitting
 
Below are some step-by-step photographs I've taken over the last 3 months - illustrating exactly how to do it. I wanted to just clarify a few extra points here that room in captions doesn't allow! I've tried to make this as comprehensive as possible, without being too lengthy - but forgive me if I've either gone on too long - or left anything out! When you've been doing it as long as I have it's easy to take some things for granted!
 
It's best to start off with a good-sized potful of the smallest seedling plants you can get. This is firstly because they will obviously have less time in non-organic compost but secondly because they tend to split up and move a lot more readily when still fairly small. Where to buy? Marks & Spencer and Sainsbury's sell the freshest and best potted basil I've found, in decent sized pots. Some other supermarkets sell plants in smaller pots, but often those plants are taller, have been on the shelf for some time and haven't been looked after too well - either under or over watered from the top - which basil hates. Those generally don't transplant as happily as smaller ones. M&S pots are generally smaller and will give you 4 -5 good clumps, depending on how they split. Sainsbury's pots will usually give you 6 clumps - as the pots tend to be larger and the seedling plants are often slightly smaller than M&S ones too, which I prefer.
 
As soon as you get the plants home, release them immediately from their straight jackets - those suffocating plastic sleeves they've been in while on the shelf in the supermarket! They will immediately relax and breathe a sigh of relief! Then put them somewhere draught free - in good light and give them a drink if they need it - by sitting them in a shallow saucer of water for a couple of minute and then draining. Never, ever leave basil sitting in water - it's the surest way to kill it fast as it rots the roots! When you split the clumps up you will obviously have to water them around the stems initially, in order to settle the compost in around the roots. But after that - never water from the top again. Definitely do not give a 'thorough drench' it as I saw one 'expert' recommend and don't use a watering can from above either as I've seen some others recommend. Always waterbetween plants that are planted in the ground - never direct a cold hose at the base of the stems - another sure way to kill it. How often? When it needs it is the answer! You can't prescribe a once or twice weekly watering any more than you can organise the weather sadly! It just needs a nicely moist, but not wet soil. If it's too wet & cold it will start to turn yellow and die - if it's too dry it will be tough and run up to flower quickly, instead of producing those lovely lush leaves you want. This is something you'll just have to learn to play by ear.
 
When dividing - always be careful not to handle basil by the stems as they bruise easily and this can potentially cause disease. Use an 'open' claw like hand around the actual root ball, just below the stems. Turn the pot around - look for a gap where it seems likely to split readily and ease it apart very gently.
 
For initial potting up I use a good free-draining peat-free certified organic potting compost. Klassman-Deilman certified organic peat-'free potting compost is the one I prefer as it's made from composted green waste grown specifically for it and it grows really healthy plants. It's free-draining too and I never lose plants in it. I also use their seed compost for raising all my seeds - it's thoroughly reliable and since I discovered it I never lose even sensitive seedlings and basil can be a bit like that in early spring! Immediately after splitting and potting up shade it for a couple of days with fleece, or put it in a shady but warm spot as it may wilt a little at first, but will soon establish new roots and relish it's freedom.
 
If raising basil from seed I always sow into modules which avoids too much handling such as 'pricking out'. I sow very shallowly and then barely cover the seeds with vermiculite. This promotes well-drained conditions and really good air circulation around the base of the seedling's stem - so they never suffer any 'damping-off' problems. Again I always water the seed tray from below by sitting it in water for a few minutes and then covering with polythene until it starts to germinate. As soon as it does, it must be uncovered immediately or it may damp off. It needs a warm propagator for germination, and then the same temperature for growing on in the warm for a week or two before gradually acclimatising to normal greenhouse or tunnel temperatures. 
 
Where to put it for growing on after potting up? Basil's never really happy on a windowsill for very long. They're generally either too scorching hot and dry it out too quickly - or they don't have enough top light. The plant will keep stretching for more light and eventually become stressed. Stressed plants tend to be far more vulnerable to greenfly and wilting diseases. Outside it's not that happy either as it hates wind and rain. Giving plants the conditions they like is the secret to keeping them happy. Think sheltered Mediterranean gritty slope or sunny Ligurian hillside - and that's a bit closer to what it likes. Not really north-west European gloom or soggy soil!  It might be happy in a warm and sheltered town garden with free-draining soil, or in a large well drained pot in a sheltered sunny courtyard - but if you want to be sure of growing the very best basil, particularly if you want a lot of it, then a polytunnel, greenhouse or tall-ish cold frame with good ventilation is essentially the best environment for it in our climate. 
 
Planting out. When the roots have filled the pots, a couple of weeks after the initial splitting and it's ready to move on - you can then either pot it on into larger pots - about 3 clumps to a 10 litre pot is what I use to crop it in, or plant the clumps into warm, rich, nicely moist soil in your tunnel - about 45cm/18inas apart. Imagine what you would like if you were a basil plant - give it that - and it should take off like a rocket!
 
Harvesting. *Never wait until you want to use basil to harvest it! Always harvest it as soon as it's big enough to use, or it may run up to flower, and become stringy, tough and tasteless! Never allow flower buds to develop unless you want to save seed from a plant. Pick shoots as they become long enough, when the plants are about 15cm/6ins high or so. Always pinch off shoots cleanly with sharp fingernails, or scissors if you want to be 'finnicky' and you don't have many plants. Take the shoot just above a pair of leaves, where there will be more shoots waiting to develop as soon as they are stimulated by picking the shoot above them. It's a bit like pruning. Remember - basil wants to make flowers to perpetuate itself - you don't want it to! It's also necessary to pick some of the larger leaves from the inside or from around the outside of the plant as it becomes bigger - as this promotes good air circulation and prevents possible disease - which can happen in large clumps of plants. Again - pinch off - don't tear them off. Never denude the plant totally though, or you may kill it. It needs it's leaves to photosynthesise so it can make food to grow. Also pick off any yellowing leaves whenever you see them - they're doing nothing for the plant by then and may cause disease if left. (*My article on 'when is the best time to harvest your produce' is a relevant read - it tells you why early morning is the best time to pick your produce.)
 
Preserving basil. Although it's nice to have some basil preserved in oil for salad dressings and drizzling, I think it's wonderful aromatic qualities are best preserved by freezing as fast as possible. You can always make herb oils and pesto in winter when you have more time. Immediately after picking, I lightly wash and dry it, spin it dry in a salad spinner and then freeze it loosely in a large bag as fast as I can. After it's frozen I just pick up the bag - give it a jolly good shake and bang it about a bit (a bit of creative visualisation can be amusing here!).  And there you have it - ready chopped basil! Then squash as much air out of it as possible and 'double bag' it. It keeps beautifully in the airtight freezer bag - preserving that just-picked aroma and flavour. I just dip into the bag full whenever I need to make a pesto or something - no faffing about with tiny separate bags - life is too short! Just a sniff of the open bag in winter is enough to transport you back to summer! (Make sure the bags are strong and won't split when doing this to prevent tragedy - frozen basil stems can be sharp and pierce bags easily!) 
 
1. A nice pot of healthy basil, plenty full enough & ready to split 2. Sit the pot in saucer of water for few minutes for a drink
1. A nice pot of healthy basil, plenty full enough & ready to split 2. Sit the pot in saucer of water for few minutes for a drink
3. Turn pot around & look for a gap in plants where it will split conveniently  4. Split root ball gently into 2
 3. Turn pot around & look for a gap in plants where it will split conveniently  4. Split root ball gently into 2
   
 5. Split the halved potful into 2 again. You now have 4 clumps  6. Fill a pot with compost & make a wedge shaped hole
 5. Split the halved potful into 2 again. You now have 4 clumps  6. Fill a pot with compost & make a wedge shaped hole
 7. Pot up clump filling with compost to same level as it was originally. Firm gently & water in.  8. Do others -You now have 4 new pots full
 7. Pot up clump filling with compost to same level as it was originally. Firm gently & water in. 8. Do others -You now have 4 new pots full
 9. After splitting, shade for a couple  of days with fleece  10. You now have 12 new full pots of basil from 3 originally - ready to plant out
 9. After splitting, shade for a couple  of days with fleece  10. You now have 12 new full pots of basil from 3 originally - ready to plant out
11. Pot nicely filled - roots ready to explore further 12. Remove pot and plant clumps 45cm/18ins apart at same level as top of compost in pot - no lower.
11. Pot nicely filled - roots ready to explore further 12. Remove pot and plant clumps 45cm/18ins apart at same level as top of compost in pot - no lower.
 13. One week on - already growing well despite cold nights. Module raised plants sown  in mid April planted on right of them. Huge difference  14. Basil seedlings sown in organic compost mid April. Pictured 3 weeks later ready for potting on
 13. One week on - already growing well despite cold nights. Module raised plants sown  in mid April planted on right of them. Huge difference  14. Basil seedlings sown in organic compost mid April. Pictured 3 weeks later ready for potting on
 15. Bushy clump of split supermarket pot in foreground, already harvested twice. 2 module sown clumps not yet harvested at rear.  16. A rare Basil - Giant Red Lettuce Leaved - has a deliciously sweet warm cinnamon flavour & leaves big enough to cover my hand!
 15. Bushy clump of split supermarket pot in foreground, already harvested twice. 2 module sown clumps not yet harvested at rear.  16. A rare Basil - Giant Red Lettuce Leaved - has a deliciously sweet warm cinnamon flavour & leaves big enough to cover my hand!

Latest Diary Entries

Latest Tweets

Listen