Providing shade for your plants will extend lettuce harvest during hot weather

Lettuce is a cool weather crop, which simply means it will always grow better during the cooler temperatures of spring or fall. It can be planted very early since it can withstand light frost. Temperatures in the 50s to 70s are ideal for maximum production.

As temperatures warm up through later spring and early summer, lettuce will change their growing habits from vegetative growth to reproductive. This happens when it gets into the 80s during the day and over 65 degrees as low temperature overnight.

The reproductive stage is marked by the plant sending up a flower stalk. The term for that is “bolting.” Bolting happens with a wide variety of plants, spinach, radishes and beets come to mind among many others.

The reason why we are concerned with bolting is that lettuce leaves will become bitter to the point of being inedible. The leaves also become very tough losing their appetizing texture.

There are a couple of things we can do to delay bolting in lettuce. One is to provide shade. That will reduce soil temperatures significantly and cool the surrounding air somewhat.

Somewhere around 30 to 50 percent shade works well for lettuce but even a small amount of shade will help. To achieve this some gardeners purposely plant their lettuce in the part of their garden that is naturally shaded by trees. Plus the temperature under shade trees is always cooler than the surrounding area.

Using garden fabrics of one sort or another is effective at blocking excessive heat from the sun. Special shade fabrics are available at garden supply places. Frost fabric can also do double duty as shade fabric.

In order for fabric to work, it must be suspended above the plants in someway. When the fabric is held above the plants, air is allowed to circulate freely avoiding hot air being trapped.

Hoops, either homemade or purchased, area a common solution for suspending fabric. The hoops resemble a half circle above the crop, then the fabric is draped over them proving the shade.

In our garden, we built wire cages around our two lettuce beds in order to protect them from being devoured by wildlife. It is really easy to simply place fabric over the top of the cage. We used an old bed sheet to provide shade on one bed.

Our other lettuce bed also has a cage over it. For that one we laid an old lattice panel over the top providing about 30% shade for those plants.

Use your imagination to come up with ideas to provide shade. I guess now-a-days people use Pinterest too.

Some serious gardeners have gone so far as to build permanent lattice structures supported by tall poles to provide shade for their sensitive plants.

The second critical element is water. Lettuce plants will need more water than they would during their usual growing season to keep them going. Any kind of stress such as a missed watering could be enough to trigger bolting.

Plant breeders have developed lettuce varieties that take longer to bolt. Some varieties such romaine are naturally very resistant to bolt and have a comparatively long growing season.

By providing shade and water, you’ll be able to harvest lettuce weeks longer than if the plants were left to grow under the hot sun.