Lettuce needs light to germinate so don’t cover the seeds with compost.

If you’ve ever planted seeds with the hopes of seeing them thrive in a few weeks only to be disappointed, then you know how difficult it can be.

The fastest germinating seeds include everything in the cabbage family – bok choi, broccoli, kale, cauliflower etc, and lettuce..

Buttercrunch lettuce is a low maintenance vegetable that rewards gardeners with mature plants in two months time. Lettuce seeds show "high-temperature inhibition", or, plainly put, won't germinate at temperatures over 85 °F / 30 °C. Lettuce seeds germinate in temperatures between 40 to 80 degrees F, depending on the cultivar. Thanks to ongoing research on lettuce traits, there are some techniques home gardeners can use to extend the sprouting season for lettuce seeds into the warmer months. Lettuce doesn't need full sun; in fact, it'll perform better if you give it indirect light and cool shade. You can start your lettuce seeds in store-bought seed trays or make your own out of an old egg carton, box or newspaper.Fill the seed trays to within 1 ⁄ 2 inch (1.3 cm) of the top with a soilless growing medium. Start checking on them the next day.

When planting lettuce for summer harvest, use slow-bolting, heat tolerant varieties. We assembled the Vegepod, and I excitedly planted heat tolerant varieties of lettuce (Black Seeded Simpson, Red Leaf Lettuce, and Paris Cos Romaine) and waited for the seeds to germinate.

For those living in zones 8 and warmer, sow your seeds in early fall for a winter harvest. Leaves wilt, toughen, and get bitter if the plant becomes water stressed in heat. It should take about seven to 10 days for the lettuce seeds to sprout. Keep watering whenever the soil dries out. Germinating Lettuce in Paper Towels. Summer Lettuce?

Seed germination is one of the fundamentals of gardening, but while it might be a basic element, there are a lot of things that can go wrong. When to Start Lettuce Seeds.

High temperatures and how lettuce responds to them are the biggest factors to deal with. Resort to starting heat-tolerant varieties indoors and moving the lettuce seedlings into the garden, preferably under partial shade, after they've developed a …

How to Germinate Lettuce Seed.

An online chart that lists ideal soil temperatures is mighty handy. Lettuce may bolt in response to the stress of high temperatures, and the leaves may become bitter as the plant puts its growth into flowering (see photo at right). Plant summer lettuce underneath tall plants or arbors, or make your own shade structure.

If you are planning on growing your lettuce in a pot then fill ¾ full with potting mix then put a layer of seed raising mix on top.

Now, plant your lettuce seeds in the prepared area and water them in well.

Lettuce and Greens are best started outdoors as soon as the soil can be worked in early spring or late summer (for a fall crop).

Keep in mind that lettuce seeds won't germinate in soil that is 80 degrees F. or warmer, so there's no sense in sowing directly in the garden in the summer. Lettuce may bolt in response to the stress of high temperatures, and the leaves may become bitter as the plant puts its growth into flowering (see photo at right). Begin planting fall lettuce in late summer so it reaches maturity when the fall air is cool. Soil Needs. If the lettuce seeds sprouted under these conditions, they would soon die out and the species would go extinct.

Thanks to research, there are some easy techniques to germinate lettuce seeds in warm weather – our article Improve Lettuce Seed Germination shows you how. Lettuce seeds germinate faster with optimal soil temperature, humidity, and air circulation. Growing Lettuce From Seed: Tips and Tricks. The slowest seeds to germinate are pepper, eggplant, fennel, celery, which may take 5+ days. Lettuce seeds germinate poorly in warm summer soil since heat may cause seed dormancy. Watch the video on my YouTube channel, “Growing Lettuce in Summer Heat in a Self-Watering, Shaded Raised Bed” to see how the Vegepod looked before it was planted, and how I …

Resort to starting heat-tolerant varieties indoors and moving the lettuce seedlings into the garden, preferably under partial shade, after they've developed a few true leaves.

Active growth takes place when days are between 60 to 70 degrees.