by Sandy Swegel
It’s only the beginning of June, but hot days can already cause your lettuce to begin to turn bitter or bolt. But an attentive gardener can keep her lettuce sweet and tasty with a few easy tricks.
Lettuce generally turns bitter when it begins to mature or bolt. The most obvious environmental factors that cause bitterness are high heat and water stress. There are some studies that suggest long day length also speeds bolting. It’s a bit too much trouble to test this and create darkness for your lettuce but there’s a lot you can do to sweeten your lettuce.
Keep it cool.
Light row cover over the lettuce in the easiest way to cool it down. Just keep the sun from baking it. Alternatively next year you can plant the lettuce somewhere it gets shade in the hottest parts of the day.
Keep it well watered.
Sometimes we don’t notice how hot it is becoming and we don’t increase our watering to compensate. Make sure your lettuce is consistently well watered and doesn’t go through stressful too wet/too dry cycles.
Thin your lettuce.
Loose leaf lettuce can get bitter from being planted too densely and not thinned. This is probably just water and nutrient stress from overcrowding, but give those plants a little more room. By thinning as lettuce grows.
Pick it in the morning.
A cool night is often enough to sweeten lettuce so pick the lettuce in the cool of morning, not just before dinner. Bring a bucket of water with you to harvest and put the lettuce directly into the water after picking.
And if your lettuce is already bitter?
No need to eat it bitter or toss it into the compost pile. Wash and dry the lettuce and put it in a crisper in the refrigerator for at least a few hours and up to a couple of days. Lettuce is one of those plants that keeps growing even after it is cut so it will often respond to its new cool humid environment by “sweetening up.”
If your lettuce is still bitter? Send it to compost or toss it in with other vegetables when juicing. You’ll get the vitamins but not notice the bitterness amid the other strong vegetable tastes.