Growing potted lettuce is one way to address a lack of space in your garden. But did you know that growing lettuce in containers can also help to prevent it from bolting? Choosing potted lettuce over lettuce grown in a garden plot can help to extend your growing season. It may also help you to avoid garden pests that might otherwise attack your growing greens.
We decided to grow potted lettuce alongside the lettuce in our raised bed this year, as a bit of an extra insurance after last year’s lettuce crop all bolted. We had bought started plants from a friend and they seemed to take really well when we transplanted them. But within about a week they were looking leggy. It wasn’t long before we realized all our lettuce had bolted. Very disappointing!
Our tiny back yard is overshadowed by several trees, so the lettuce may have lacked sunlight when it was initially transplanted. Last summer was very hot and dry, making it tough to keep the soil moist. We also transplanted our starts a bit late in the season. So it could have been a combination of several factors that led to the crop failure.
This year we’re addressing some of the issues by planting from seed early in the season, and also by growing some of our lettuce on our land share instead of just in the yard. I’ve also opted to try growing some potted lettuce as well.
In this post, I will discuss the benefits of potted lettuce and some of the lettuce varieties that are suitable for growing in containers. I will also look at the choice of containers and soil, as well as how temperature and sunlight affect your lettuce plants.
Growing Potted Lettuce to Improve Bolt Resistance
The ultimate goal of any organism is to ensure the survival of its kind. One of the best ways a vegetable plant can do this is to produce seeds. This is great when the seed grows in the part of the plant you want to eat, as it does with peas, tomatoes, or peppers. But how does lettuce reproduce?
If you usually buy started lettuce plants, you probably aren’t all that familiar with lettuce seed. But even those of us who grow our lettuce from seeds may never have seen how that seed is produced by the plant. That’s because we try to harvest lettuce before it gets the chance to set seed. You see, when lettuce goes to seed it changes the whole plant. The leaves become tough, and their sweet crispness disappears. Instead, the leaves start to taste bitter. Lettuce that has gone to seed just isn’t pleasant to eat.
But if you’re into seed saving, you may have allowed your heirloom lettuce to go to seed at the end of the season. You only need to do this with a handful of plants. They’ll produce enough seed for next year’s crop. The lettuce tends to grow more upright when it’s producing seed, and it sends up a tall, cental stalk topped by little dandelion-like flowers. Each flower will produce seed.
Preventing Lettuce from Bolting
When lettuce tries to set seed too soon, we call it bolting. You get the sense of urgency and prematurity in the very word we use to describe this process. Usually, we’ve harvested all of our lettuce before it can go to seed. But if the plants get too much heat or light, or if they are stressed by a lack of moisture, they will bolt. Growing potted lettuce can help to reduce the chances your plants will bolt.
Because potted lettuce is portable, you can move the plants around in order to give them the best possible growing conditions. Early in the spring, place your containers where the lettuce will get at least six hours of direct sunlight each day. But if the weather turns hot before your plants are mature, you can move potted lettuce to a cooler part of the yard where they can benefit from partial shade. Moving them closer to your deck or window might also help you remember to water your potted lettuce. Since maintaining even moisture is important to reducing bolting, this can extend the life of your crop when conditions are dry as they were here in BC last summer.
If you find that no one spot in your yard is ideal for growing lettuce, the cool thing about potted lettuce is you can move the containers around during the day. This may be necessary if there is no one spot in your yard that provides enough sunlight hours. Not getting enough light, especially early in the growing season, can cause your lettuce to get leggy. While that’s not quite the same as bolting, it does cause the lettuce to grow taller. So you won’t have nice heads forming on your lettuce plants.
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Lettuce prefers cool temperatures. Plant it about two weeks before your last frost date for best results. If temperatures climb too high or lettuce gets too much sun or too little water, it will bolt. Purple lettuce varieties and Batavian (aka French or summer crisp) lettuce are slower to bolt. Growing lettuce in containers can also improve its bolt resistance. … … … … … … … #vegetable #vegetables #veg #veggies #garden #gardening #vegetablegardening #containergardening #containergarden #lettuce #eatfresh #food #foodstagram #instafood #healthy #gardeningtips #spring #salad #greens #organic #plantbased
Extending Your Growing Season with Potted Lettuce
Potted lettuce is ideal for the eager gardener who wants to get a head start on the season. The soil in containers tends to warm up sooner than in beds set at ground level. So if you want to start your lettuce just a little earlier in the year, try leading off your spring crop by growing lettuce in containers.
If you are growing lettuce for the fall, choosing potted lettuce helps to extend the season into the cooler months. Since mature lettuce tolerates frost less well than young seedlings, cooler nights can bring an end to your crop before you’ve had a chance to harvest all your greens. But with potted lettuce, you can move containers closer to the house to provide them shelter from the cold. You can even move pots of lettuce into a cold frame, or bring your lettuce indoors at the end of the season so it can continue growing.
Even if you choose to grow rows of lettuce in a larger vegetable plot or raised bed, you may want to plant some potted lettuce to supplement the main crop. Growing lettuce in containers can give you a few extra weeks at either side of the growing season, so you can be enjoying fresh greens from the garden for more weeks of the year. For a Canadian gardener who has to buy grocery store lettuce pretty much half of the year, that’s a huge bonus!
Lettuce Growing Instructions
How to Grow a Baby Lettuce Salad in Containers
Potted lettuce is a great choice if you eat a lot of salad. You can enjoy baby lettuce salad early in the season, and continue to eat fresh lettuce from your garden right through midsummer. Just choose lettuce varieties that are suited for container growing and give them the right kind of soil in the right container. Nature will take care of the rest!
One caveat about growing potted lettuce is that the soil can dry out faster, especially in shallow pots. Be sure to water your lettuce regularly, and to keep an eye on soil moisture. You will have to water more often than when you grow lettuce in a vegetable garden. Lack of moisture can trigger bolting, so pay extra special attention to watering your lettuce when the weather is hot and dry.
Growing Lettuce in Containers: Varieties to Try
You can grow both looseleaf and heading types of lettuce in containers. If you’re growing potted lettuce because of its increased bolt-resistance, as I am, try to choose lettuce varieties that are slow to bolt. In field trials, Batavian lettuce held up best to bolting. These varieties are often labelled “summer crisp” or “French crisp” lettuce, and are somewhere between Butterhead and Iceberg lettuce.
Purple-leaved lettuce varieties are also a good choice for potted lettuce. Higher levels of anthocyanins apparently lower the freezing temperature of the lettuce and slow its growth. This makes purple lettuce or red lettuce more resistant to both drought and bolting.
We happen to have a lot of ‘Grand Rapids’ lettuce seed this year, so I’ve chosen this variety for my potted lettuce. Other lettuce varieties you might want to try for growing lettuce in containers include: ‘Nevada,’ ‘Magenta,’ ‘Rouge d’Hiver,’ ‘Reine des glaces’ and its relative ‘Jack Ice,’ ‘Black Seeded Simpson,’ ‘Green Ice,’ and ‘Red Sails.’
Choosing the Right Container for Potted Lettuce
Lettuce doesn’t have very deep roots, so you can choose a fairly shallow container for your potted lettuce. It should be between 15-30 cm deep, and allow each lettuce plant to have about 15 cm of lateral space around it. The diameter of your container depends on whether you want to grow a single plant in each pot, or several lettuce plants together.
Containers can be made of clay or plastic. Just keep in mind that clay pots are more porous and tend to dry out more quickly. Growing lettuce in a shallow pot already means soil will dry out faster. So keep moisture in mind when choosing your pots. If you’re not great at remembering to water your plants, or if drought is a problem where you live, you might want to stay away from clay pots. If you don’t like the looks of plastic, you can always tuck them into a basket or a larger ceramic container.
The Best Soil for Lettuce Grown in Containers
Use soil formulated specifically for containers. This soil has ingredients that help with drainage and aeration. You can create your own container mix using a recipe. But before you choose, shop around a bit. We found that buying the peat moss, compost, vermiculite, etc. separately and making our own soil mix was quite expensive last season.
This year, I found 56 L bags (sometimes labelled “2 cubic feet”) of container soil at our local home Hardware. The cost was less than what I would have paid for ingredients, and it was a lot easier to find space in our little yard for just one bag. If it works out well, I’m going to stick with this more economical soil option next year.
You can sow lettuce seeds directly in your containers about two weeks before last frost. Or buy started lettuce plants and transplant them into your containers, allowing 15 cm of space between plants. If you start with seeds, remember to cover them only lightly, as the seeds need some sunlight to germinate.
Thinning and Harvesting Potted Lettuce
When your lettuce seedlings are about 2.5 cm tall, thin them to about 10-15 cm apart. Use scissors to snip the seedlings just above the ground level. This allows you to remove the extra seedlings without disturbing the roots of your potted lettuce. As the plants grow, you can come back and thin them more as needed. If you’re growing looseleaf lettuce, just a cut and come again approach to harvesting the leaves will probably be enough to ensure your plants get enough sunlight and air circulation. For head lettuce, be sure each plant has enough space around it. Otherwise, the heads will be small.
Probably the best way to use potted lettuce is to use it as a cut and come again crop. Don’t pick the entire plant at once. Instead, simply harvest a few outer leaves from each lettuce plant. The lettuce will grow new leaves to replace what you’ve cut away. You can cut the outer leaves of your head lettuce, even if you want to later harvest the whole heads.
When harvesting head lettuce, cut the plant about 5 cm above the soil. Do not pull the lettuce up by its roots or cut it too close to the bottom. If you leave enough of the plant in the pot, it will usually grow back. This will produce a whole new crop of baby lettuce leaves. Lettuce should grow back at least once each season.
As long as you keep your lettuce happy, you’ll get twice the harvest from your crop. Remember, if outdoor conditions are too hot or your plants are getting too much sun, move your potted lettuce to a location that provides a bit of cool shade.
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Original content © 2018 Kyla Matton Osborne, aka #RubyWriter
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