One of my goals at the Derwood Demo Garden this year was to keep lettuce growing through the whole season. So far it’s working! Here it is July; we’ve had a rain break following some hot dry weeks, and today we harvested many bags of lettuce that was still sweet and tasty.
So how do we make this work, and how will we keep it up through the hottest months of the summer?
- Pick a good location. The salad tables are in a spot that gets a few hours of morning sun and is shaded all afternoon.
- Water regularly. We have drip irrigation on the salad tables and also do additional watering when the weather is hot and dry.
- Choose varieties that can take the heat. There are lots of heat-tolerant lettuces out there. You can also look for “slow to bolt” in the description, or choose a “summer crisp” type. Summer Crisp is one of the varieties that’s doing well for us right now. Also Cherokee, Muir, Green Star, Buttercrunch, Summer Bibb, Toretto, and Seafresh.
- Use succession sowing. As soon as one planting of lettuce starts to bolt, pull it out and seed a new one. Make sure to keep the new seeds well-watered. Laying a piece of floating row cover or other cloth directly on the soil until the seeds germinate helps.
I am also trying a heat-tolerant green in the cabbage family called Tokyo Bekana as a lettuce substitute. Hopefully the combination of all of these should get us through August.
By Erica Smith, Montgomery County Master Gardener