More and more food plants are being grown using water as a medium. It allows intensive growing, providing a lot of food in a small space.
What you'll need:
A large plastic pot
Chunky coconut fibre/mulch block (pref. no added nutrients)
A bucket or deep plant tray
Basil (or other herb) seedling
Coco specific hydroponic nutrients (hardware or hydroponics shop)
Soak the coconut fibre block in water. Once it is expanded it may be a good idea to rinse it a couple of times to remove some of the tannin. Don't let it drip on pale paving, it may stain for a while.
Simply pot the seedling into the coco mulch as you would any other plant, it will have lots of spaces in it but that's okay.
Give it a water in with the nutrients. Only make up how much nutrient you want to use.
Remember to give it a drink every couple of days, more often when it's hot and as the plant gets bigger. It's best not to let the plant sit in deep water for too long, but again, once it warms up, you may need extra watering anyway and it can use a bit up in a day.
It will need a few hours sun a day to keep it happy. We started ours a bit early this year but it should be okay once it warms up.
I also am trying out a little window box Roma tomato in a hydro bucket too and so far it looks good.
Enjoy!