LEEK NORTHERN LIGHTS ~ a British bred stunner, leaves turn purple, combined with a super taste 50 seeds SOW: March to May for harvest from December through to the following May. We sow our leeks in modules or seed trays rather than a seed bed as we find it easier to separate them when transplanting. GROW: After 10-15 weeks, when they are large enough (about 20cm tall), plant out one leek per 15cm deep hole made with a dibber or stick. Water the leek into the hole and let the soil wash in but try not to get soil in between the leaves. It sounds fiddly but leeks are worth the trouble. If it is dry after planting water gently every day but otherwise just leave them to grow! EAT: Leeks can be lifted when you need them so you can enjoy them fresh. Pull when pencil thick for use as a baby veg.