A fresh sowing of lettuce in late summer keeps the garden productive through fall. But while lettuce thrives in cool weather and even tolerates light frost, getting it established early enough to bear can be tricky. Lettuce seeds have poor germination when soil temperatures exceed 80 degrees. To achieve better germination, you can start seeds indoors, then transplant into the garden once established.
Other tips that may improve success:
- Starts seeds in pots in a shady area, or use heavy shade cloth in the beds where you will plant.
- Plant seeds in a tray of damp soil or potting mix, then refrigerate for four or five days before taking outdoors. Seedlings can be transplanted once they've emerged and developed leaves.
- Sow seeds of lettuce in containers or hanging baskets out of direct sunlight and keep soil moist. Hanging baskets are particularly convenient for "salad mix" lettuce, enabling easy harvest and relocation of plants when necessary to avoid extreme heat or cold.