new and need help please

Hi smiffy, both of those are sown in the spring.

Sweet corn you sow indoors in pots or trays around Mid April and they need to be planted outside in mid May onwards (depends on where you are and your last frost date), choose a sunny spot. The plants get pretty big (6 ft and more) and need to be grown in blocks for germination, so you do need a lot of space.

Leeks are also sown in Mid April, again in trays or pots indoors (or in a greenhouse). They are planted outside later, in mid summer when the stems are pencil thick.