Green Bowl Lettuce Seeds A mainstay amongst salad crops. For protected all year round cropping & open ground production. Approximate crop spacing: (in row x between rows) 35cm x 38cm Lettuce needs light to germinate, so do not cover the seeds with compost. in your polytunnel or greenhouse you can start sowing lettuce in late January & continue on with successional sowings until August. During late spring & summer lettuce will grow better outdoors. Green Salad Bowl Lettuce Vegetable Seeds - 1100 Organic Easy Quick Growers