Lettuce varieties that thrive in summer heat

If you plant lettuce in summer, be sure to choose a variety that thrives in summer heat.

June 17

I’m excited for the week ahead as the forecast is finally on our side! Just a bit of rain and then lots of sunshine and even some high temperatures for the heat-lovers in our garden. The Super Bush tomato that I put in the Tomato Success Kit is leaps and bounds ahead of those in beds and has brilliant, dark green leaves. The strawberries are ripening fast and the asparagus is on its way out. We are officially transitioning into summer, an occasion most notably marked by the bolting spinach.

Spinach that's going to seed


Bolting occurs when a plant shifts its focus from leaf production to sending up a seed stalk for reproduction. This transition, brought on by longer daylight hours (and often accelerated by heat) causes the plant to release compounds that change the flavor of the leaves from sweet to bitter; in fact, sometimes you can taste this change coming. Leafy plants, such as spinach, lettuce, cabbage, and beets are all prone to bolting. To combat bolting, you could try to limit sunlight exposure using shading techniques (here’s one Shade Net), but a more reasonable solution is to choose a slow-bolting variety and to reseed frequently.

June 19

Planting Summer Lettuce: I have to admit that I have struggled with planting lettuce in the past because the tiny seeds make me nervous. Should I scatter them or push them into holes? What about all of the lumps, bumps, sticks and rocks in my soil — how will the tiny sprouts ever push through those? Luckily, a another gardener showed me a trick a few years back and now this task is both simple and enjoyable.

First, I choose a heat-tolerant variety of lettuce. Next, using a stick, I draw shallow trenches in the soil to create planting rows:

Rows for lettuce

Then, I sprinkle the lettuce seeds in the trenches. I am always amazed at how hard they are to find.

Lettuce seeds are hard to see

To finish, I fill in the trenches with Germinating Mix and press down ever so slightly. Not only is Germinating Mix free of larger pieces and parts that can be tough obstacles for tiny seeds, it is also perfectly balanced and contains trace minerals to support your sprouts as they grow into seedlings.

Here’s how the bed looked after it was watered:

Well-watered rows of lettuce

This planting technique works well with many small seeds, such as lettuces, kale, carrots, celery and amaranth.

Have you had any experiences with bolting plants? What’s your solution? Tell us all about it in the comments below.