I never have much luck growing basil from seed or keeping basil plants bought from supermarkets indoors for any length of time. Last year I planted an indoor plant outside in the open ground which survived in the open ground all summer. This year I'm going to have a go at taking cuttings from a plant I recently bought from a supermarket (before it dies on me) - something I've never done before. The instructions seem simple enough
1. Choose 10cm/4-inch stems and using a sharp blade (not scissors) cut just below a leaf node - the part on the stem where new leaves/stems sprout.
2. Strip any leaves from 3/4 of the stem then place in a glass of water and leave in a very bright but not too hot place until roots start to form on the stem making sure to change the water every couple of days.
3. Once the roots are around 5cm/2-inches long, pot up individual stems into pots at least 10cm/4-inches wide, filled with potting compost. Water in and then place in direct sunlight. It recommended that the plant gets at least six hours of bright, direct sunlight each day.
I've done steps 1 and 2 as you can see in the picture above and hopefully in a few weeks I'll have 4 new basil plants potted up whilst still having the main plant available for use in my kitchen