I often hear people say that lettuce can only be grown in the spring or fall because it would become bitter in the heat of the summer. This isn’t true at all! You can actually grow lettuce all summer long and I have completed some research and experiments of my own with great success!
So how do you avoid growing bitter tasting lettuce in your garden? Keep your lettuce in a cool place, out of the hot sun to prevent it from bolting quickly and becoming bitter.
This is a very straightforward and general answer but I have a lot of tips to follow and methods that I use in my own garden to have fresh lettuce all summer long! First, let’s learn some causes of lettuce bolting and becoming bitter and then we will learn some ways to prevent it.
What Causes Lettuce to be Bitter?
Understanding the causes of
In case you aren’t familiar with the term “bolting”, it is when a plant grows quickly, stops flowering, and produces seeds. This generally happens at the end of the plant’s life cycle or when the plant becomes too stressed.
Without a doubt, lettuce is a cool season crop. It will continue to produce its leaves for multiple harvests as long as the plant is healthy and kept at cool temperatures.
Lettuce will bolt and become bitter any time the plant feels like it is stressed. God created plants in a way that they will reproduce on their own by producing seeds. Once the plant gets stressed, it goes into survival mode. It says, “Uh oh, something isn’t right here and I need to put all my energy into producing seeds so I can thrive again next season!”.
Here are some common reasons that cause your lettuce to bolt and become bitter:
- Heat stress. Since lettuce is a cool season crop, the summer heat will cause the plant to mature and start producing flowers and seeds instead of producing leaves.
- Poor soil. Lettuce has shallow and fairly thin roots so it needs loose soil and good drainage, otherwise the plant will become stressed and start to bolt.
- Nutrient deficiency. Like any plant, without the proper nutrients, it is not going to grow very well. Lettuce is a
fast growingvegetable and if its growth is stunted in any way it is likely to bolt. Under watering. Lettuce leaves are full of water! Without enough water, the leaves will wither or turn brown and cause them to become bitter. The more water in well drainingsoil the plant has, the sweeter your lettuce will be.
Now that we know what causes lettuce to bolt and become bitter, it’s fairly easy to see how we can prevent this and grow ourselves some very healthy lettuce. Next, I’ll give you some tips on how I grow my own lettuce successfully all summer long – even when temperatures reach into the 80s and 90s.
What are Some Tips to Avoid Growing Bitter Lettuce?
Grow in partial shade. In order to keep lettuce cool, try growing it in a spot that gets some shade – preferably in the afternoon when the heat is more intense. If you don’t have a shady area, plant your lettuce around other taller plants that can provide shade, such as tomatoes or trellised crops.
Grow in containers! This is a method that I use the most for lettuce. By growing in containers, the lettuce can be moved into the shade when needed, like next to a house or shed. I typically provide my lettuce with cooler morning sun and then keep it in the shade for the afternoon.
Use shade cloth. You can build some supports around your garden and use shade cloth to block some of the sun from the plants. Different levels of shade cloth exist that you can buy depending on how much sun you want to block.
Keep your soil healthy. Add an inch or two of compost to the top of your soil every fall to add back nutrients. Keep your soil covered with some type of mulch during the winter, such as shredded leaves, grass clippings, or wood chips.
Keep your soil cool during hot temperatures. As I already mentioned, keep your soil covered with mulch! This will block the sun, keep the roots of your plants cool, reduce evaporation and retain more moisture in your soil.
Water! It’s important to monitor the moisture level of your soil and water your plants only when necessary. This is especially important during a heat wave when plants need to be watered each day in the early morning or late evening.
Succession planting. As mentioned, lettuce is a cool weather crop, so it is naturally going to last longer in the spring and fall. While it’s definitely possible to grow lettuce in the middle of summer with the methods described, lettuce is still going to bolt eventually and at a quicker pace than it would in cooler temperatures.
I like to succession plant my lettuce so I always have a continuous crop. Every two to three weeks, we plant more lettuce from seed in a new container or spot in our garden.
By the time one batch of lettuce bolts, we have another batch that is in the middle of its maturity and one that is just sprouting. The main picture at the top of this post is my own example of this in my garden!
This Greenstalk Vertical Garden would make a really awesome salad garden/tower! It is unique from other grow towers with its efficient watering system.
I just recently purchased this grow tower and will be using it this year! I will be doing a full review of it at the end of the season. It would be easy to succession plant lettuce in these different pockets. Also, it can move on wheels so you can easily move it in and out of the shade and spin it so certain plants receive more sun than others!
If you would like to purchase this and learn along with us, you can use this affiliate link or our coupon code to receive $10 off your purchase! Use “DNDG10OFF” at checkout!
How to Remove the Bitterness from Lettuce
If you have picked some lettuce and you realize it is bitter, you don’t necessarily have to throw it out!
Some people have found that soaking the lettuce in water could remove some of the bitterness.
Others suggest that the bitter lettuce can be stored in high humidity and in the coldest spot in the refrigerator for a few days. This could remove some of the bitterness.
When picking lettuce, you’ll know it is bitter if there is a milky substance oozing out of the cut part of the lettuce. If this is the case, try picking your lettuce right away in the early morning. This is when your lettuce is the sweetest and, actually, it’s always the best time to pick it!
Bitter lettuce can also be cooked! Find and use it in recipes that call for cooked spinach or kale and it will turn out great!
“A person who is full refuses honey,Proverbs 27:7
but even bitter food tastes sweet to the hungry.”
What are Some Heat Tolerant Varieties of Lettuce/Greens?
There some varieties of lettuce and other salad greens that you may find easier to grow during hot temperatures. Below are some ideas you can try in your area!
- Paris cos romaine lettuce
- Super red romaine lettuce
- Ruby red leaf lettuce
- Black seeded
- Most varieties of kale
- New Zealand spinach
Check out Our Favorite Products page to find everything you might need to help make your garden a success!
Is it safe to eat bitter lettuce? While it may not taste that great, eating bitter lettuce will not cause harm in any way. No known toxins or issues are associated with eating bitter lettuce.
How can I store lettuce to last longer? Wash the lettuce and then store it in a plastic bag or container. Layer the lettuce in between paper towels to help control moisture. Do not store the lettuce in the same drawer or area as apples, pears, or tomatoes because these fruits release ethylene gas, which can cause your lettuce to spoil.
How do I know when to harvest my lettuce? Lettuce can be harvested at any time as loose leafed, cut and come again lettuce. Younger lettuce plants will have the best taste. Remove a few leaves from each plant by picking the leaves off at the base. Never remove more than one third of the leaves of a lettuce plant at one time.