Alys Fowler: Aromatic basil, and the Chelsea chop

September 8, 2011 Categories: Gardening

How to ensure your basil will really pack a punch, plus get your perennials to flower again

Supermarket basil sucks. Sure, it’s superior than dried, or none at all, but good basil has to be home-grown. And the trick to really aromatic basil is to ration its water intake, to?ensure that it?grows slowly.

Basil germinates as low as 13C, but is quickest at 20-25C (ie a sunny, south-facing window). Basil seed is light-sensitive, so don’t bury it too deep or nothing will happen. Lightly press the seed into compost, barely covering it, then give it a good soak. Sit the pot in a bowl of water – you need to keep the seed moist to start with – and cover: a clear shower cap is brilliant here, because it fits over any pot and the elastic bit keeps everything sealed in. Leave this on until you see the first sign of growth, then whip it off and don’t water again until the seedlings stand up strong. Too much water now is lethal.

Now, where to grow it: outside or inside? Ancient Greek doctors thought that basil grew ideal in the gardens of those who suffered misfortune, and so shouted abuse as they sowed it. I’m all for a good rant, but if you want really strong-tasting basil, you need to take it outside for a while. That said, basil is sensitive to the cold – more than a couple of nights below 10C and it turns black and wilts. Some state it’s not worth growing outside because the leaves can turn tough and ragged in response to the weather, and while it might not be the basil for garnishing pizza, boy, does it pack a punch. The harsher conditions bring out the flavour. And again, don’t overwater, else you’ll get aphids, rot, wilt and sappy flavour. The ideal time to water is in the midday sun, when the plant will drink swiftly and excess water will be burnt off before night.

There are so many types of basil (Chilterns Seeds has a good list). ‘Sweet Genovese’ is the sweetest, and has a long period of harvest. ‘Napolitano’ has big, crinkled leaves, needs a hot summer, and makes great pesto. Greek or bush basil is a?tiny-leaved plant that is left alone by slugs. And look for the lovely round mounds of ‘Finissimo verde a?palla’. Lemon basil, or kemangie, is pretty with thin leaves, and is good with fish and poultry. Holy basil (Ocimum sanctum), which tastes dramatically different from Italian basil, is ideal used raw. ‘Cinnamon’ or ‘Thai’ basil has purple-veined leaves with rose-coloured flowers, and is good in curries and chutney. ‘Red Rubin’ is a?dark purple variety that lends itself to the flower garden. And ‘Purple Ruffles’ looks lovely in a container.

Alys’s tip of the week: how to do the ‘Chelsea chop’

There’s an old nurseryman’s trick called the Chelsea chop. Hideous perennials that had completed flowering and thus couldn’t be sold were given a haircut around the time of the Chelsea flower show. These plants would respond with a?new flush of foliage and flowers in time for later summer sales. This works wonders with pulmonaria that are beginning to look a tiny exhausted around now. Shear the whole plant to the ground and give it a?good water. New?leaves will swiftly appear, as will, with luck, a few more flowers. Brunnera macrophylla responds in much the same way. Leave geraniums alone and by mid-summer they will have flopped all over the place, showing off their hideous middles. But chop now and you’ll get a neat usage and more flowers. You can also pinch out the tops of summer-flowering perennials such as Sedum specatbile, asters, heleniums and eupatorium (the latter three you can chop in half). This will slow the growth, but not flower production, which is handy in windy situations, because a much shorter plant won’t need staking.