Sleeping's rarely a problem after a few hours pottering on the veg plot, but should insomnia strike, fresh Chamomile tea is one of the nicest cures going. It's very easy to grow, pretty, and takes up very little space.
Time from seed to plate: 8 weeks
Chamomile is very straightforward to grow. Sow seeds in April or May by creating a shallow groove across one of your beds about 1/2inch deep, and sprinkling in seeds aiming for one every half inch or so.
Leave 12inches between rows, then firm the soil back and water.
Once your seedlings come up, then them out to give each plant enough space to grow. Leave gaps of 6inches between plants.
Start harvesting the flowers when the plant is in full bloom - normally in June. Use them fresh or dried to make tea. The flowers are also a nice addition to salads.