For those who do not know yet, sow is a fancy word for planting.
Verb: plant (seed) by scattering it on or in the earth.
"fill a pot with compost and sow a thin layer of seeds on top"
How and where to sow:
It is important that before you sow or plant new vegetables, you must clear spent summer crops. If not, plant material left in the soil can harbour pests and diseases that can impact the health of the replacement seeds. Pull up the old plants, getting out all the roots - make sure all pre diseased material is best burnt or put in the bin. If planting in soil, make sure to fork in new garden compost or add as much mulch as possible to refresh the soil. If choosing to grow your seeds in pots, replace the compost.
If you're into crop rotation, growing two crops in the same spot in the course of one year can make it tricky to follow a commonly seen four-year rotation plan. Many veg, such as courgettes, French beans and runner beans and salad leaves, don't need to be rotated and can be slotted in anywhere.
Two veg families that do benefit from crop rotation, to avoid the build up of soil-borne diseases, are the brassica family (cabbages, rocket an oriental leaves) and the family of alliums (onions, salad onions and garlic). Brassicas can suffer from club root, and alliums from white rot, both of which persist in the soil. If you’ve ever had outbreaks in the past, make sure not to grow any crops from the affected group in the same area of ground until the problem has cleared, which can take several years. In a small garden, the most practical way to do this is often to grow in large containers of fresh compost.
For other veg families, try and leave at least a one-year gap between growing veg from the same family in the same soil.