How to grow lettuces

  • During winter we recommend eating leafy greens like kale, mizuna, spinach, mustard, radicchio and mustard. But when spring comes along we need a change and that comes in the form of lettuces.
  • Lettuces grow best in spring and autumn because they like moist soils and cool air. If you do plant them during summer, it’s best to find a spot that’s shaded for a good part of the day. Otherwise lettuces will dry out too easily and get tip burn.
  • Lettuces taste best when grown quickly. They’ll only taste bitter if there’s not enough moisture in the soil or if the soil is not nourishing enough for the plants.
  • There are a variety of lettuces you can grow: the traditional lettuce we all once grew is Iceberg; then there’s Cos lettuce which is the key ingredient in a Caesar salad; Little Gem is a Bibb lettuce that’s similar to a Cos; Buttercrunch and Tom Thumb are soft lettuces which you can eat in a single meal; then there are Oak Leaf lettuces like Cocarde – Rob reckons the birds are not as interested in red Oak Leaf lettuces as they are in green leafed varieties; and finally there are the Batavian varieties like Canasta – these are hardy lettuces which will survive in temperatures from -3 to 30 degrees.
  • Rob also plants large-leafed rocket to spice up a lettuce salad.
  • Prepare your garden bed with a good amount of compost and fork it all in.
  • Then you need to add nitrogen for leaf growth – we’re adding sheep pellets and blood and bone, and phosphorus for root growth – we’re using volcanic rock dust.
  • Use a spade or fork to work the fertiliser into the top layers of the garden bed.
  • Plant lettuces about 30cms apart. When growing vegetables organically you need good air movement between plants. Good air movement prevents diseases like downy mildew in lettuces. Also plant away from the edge of your bed as you’ll need to cover the bed with hoops and netting to protect the plants from birds and animals, so give yourself space.
  • One of the main problems with growing lettuces is slugs and snails. See last week’s webisode for ways to trap them.
  • Another way of deterring slugs and snails is by using diatomaceous earth, available at garden centres and hardware stores.
  • Diatomaceous earth is an all-natural product made from tiny fossilised water plants. It’s a naturally-occurring siliceous sedimentary mineral compound from microscopic skeletal remains of unicellular algae-like plants called diatoms. These plants have been part of the earth’s ecology since prehistoric times. It’s believed that 30 million years ago the diatoms built up into deep, chalky deposits of diatomite. The diatoms are mined and ground up to render a powder that looks and feels like talcum powder. Diatomaceous earth is approximately 3% magnesium, 33% silicon, 19% calcium, 5% sodium, 2% iron and has many other trace minerals such as titanium, boron, manganese, copper and zirconium. This big boost of silica to the soil promotes great plant health.
  • To slugs, snails and insects diatomaceous earth is a lethal dust with microscopic razor sharp edges. These sharp edges cut through pests’ protective covering drying them out and killing them when they get covered with it. If they ingest DE it’ll shred their insides. Grim!
  • Next we stretch our hoops over the bed. See here for how to make hoops
  • Cover securely with bird netting. If your soil is dry, give it a good soaking after planting and before applying the diatomaceous earth.


Camera: Jarod Murray
Editor: Thomas Asche
Production equipment and post-production services provided by The Black Forest Breathes