Learn how to grow lettuce in Central Texas or any other region where winters are mild. This post is a curation of all the tips and tricks collected over the years.
When to grow lettuce in Central Texas?
Lettuce is a cool-season crop that thrives in temperatures 75F (25C) and below. If the weather is warmer than that, it tends to taste bitter and bolt or go to flower.
In Central Texas, it is a bit tedious to grow lettuce successfully, especially if you have a favorite variety. A rule of thumb is to put your lettuce out when the temperatures are consistently under 75F (25C), and that’s mostly around October.
The good news is that the period of growing lettuce is long. Your first sowing would be in October, and the last chance to sow is in March. In between, you got five months to get your lettuce in the ground.
The right lettuce variety for warm climate
When choosing lettuce seeds for your warm-climate variety, you must look into its heat tolerance.
In our regions, winters are mostly mild with occasional cold snaps. Our summers are long and sometimes take over the fall season. Springs are almost non-existent as the transition from winter to summer happens in a blink of an eye.
For that reason, the lettuce you choose for your garden has to be able to survive the lingering heat on both ends of the growing season.
How to grow lettuce in mild-winter regions/ Central Texas?
Most gardeners would say lettuce is easy to grow, just sprinkle seeds in the soil and voila! You got lettuce.
As a Central Texas gardener, I didn’t find that to be true, except for the seed germination part. It was hard to get a good harvest that would contribute to a family meal. You can fill up one plate or two, but that’s about it.
Fortunately, there is a way to grow enough lettuce, in a small garden, for a family of six to enjoy along the season.
1- Choose a heat-tolerant lettuce variety
Here is a list of some varieties that grow well, from personal experience, in a warm climate.
- Sanguine Amelioree
- Bronze Beauty
- Merveille Des Quatre Saison
2- Store transplant vs direct sow vs start indoors
A) Planting store-bought lettuce transplants
From personal experience I advise against growing lettuce from store-bought transplants for the following reasons:
- It is almost impossible to find a variety that grows well in the warm weather. Most production nurseries are located up North and grow for the Northern regions.
- Getting a packet of seeds is much cheaper and less heart-breaking in case of failure.
- Lettuce bolts easily when due to transplant shock.
B) Direct sowing lettuce seeds
Direct sowing lettuce seeds is very easy and works well with gardeners with decent space.
- Prepare the soil by amending it to improve its texture and drainage.
- Mark shallow rows using a stick or your hand, spacing them one foot apart.
- Sprinkle the seeds sparingly to reduce the amount of future thinning.
- Lightly cover the seeds with dirt, don’t bury them too deep. Lettuce seeds are very delicate and do need sunlight to germinate.
- Water with a light misting hose to avoid misplacing the seeds. Keep your soil moist but not puddle wet.
- Protect your seeds from birds and harsh sun by covering them with some sort of shade cloth.
- The seeds should germinate in seven to ten days when fresh. They take longer with every added shelf life year.
- Once the seedlings reach an inch height or so start thinning. This is applicable to head lettuce, where you need to space them six to eight inches apart. You can leave leaf lettuce alone as it does not need to form ahead.
C) Starting lettuce seeds indoors
This is my favorite method of growing lettuce in Central Texas for the following reasons:
- You get ahead start on the season while waiting for temperatures to come down, which may take some time.
- It is more suitable for small gardens, where space is limited. Sowing seeds directly has no guarantee. Occupying the space can be annoying when you can grow something else instead.
- Starting seeds indoors is economical since you don’t use the whole packet of seeds. This is very important when your favorite varieties happen to be on the pricey side.
How to start lettuce seeds indoors?
- Use one compartment shallow container instead of cells.
- Fill the container with a pre-moistened seed starting mix. Don’t use garden or potting soil for they are too heavy and stay wet for too long.
- Sprinkle seeds sparingly over the soil. Don’t use the whole packet, it’s just too much.
- Cover the seeds lightly with the soil, perlite, or vermiculite.
- Spray them with a mist of water to ensure the top is moist.
- You may cover the container with a Ziploc or a plastic cover. This is optional if you can keep a diligent eye on the moisture level.
- Place the container under a grow light or on a bright window sill.
- The seeds should come out in a week, more or less, depending on their freshness.
- When the seedlings reach an inch of growth, carefully lift them using a small spoon or fork. Transplant them to slightly bigger containers.
- Keep them under the light.
- Start feeding them with low concentration fertilizer, such as seaweed.
Read more about seed starting basics and seedling care here.
When to start lettuce seeds in Central Texas?
If you decide to start lettuce seeds indoors, the month of September is the best time to do so. Look after your seedlings until the weather permits to put them out. The sowing window is open until April.
Grow Lettuce in pots
You can grow lettuce however you want as long as the soil is fertile and well-draining.
If you decide to grow them in pots, you can plant one head lettuce in a quart-size pot. You can also sprinkle seeds for leaf lettuce in a shallow plastic tub, six inches deep.
Keep in mind that the soil in pots get depleted from nutrients fast. Make sure to fertilize every two to three weeks.
What kind of soil is best to grow lettuce?
Lettuce needs light, fluffy, and fertile soil. Adding compost improves any kind of soil. If it is sandy it improves its water retention. If it is heavy clay, it loosens it up and improves its drainage.
How much sun does lettuce need?
Lettuce is among the vegetables that tolerate less light. It needs five to six hours of direct sunlight. Anything less may cause slow growth and encourage slugs and snails to attack.
How to plant lettuce plants?
When transplanting lettuce in the ground, try to avoid excessive handling of the roots.
- Flip the pot upside-down into your palm. Squeeze the sides of the pot, then gently tap on the base. This will easily release the root-ball into your hand.
- The planting hole should be as big as the root ball.
- You may add a slow-release dry fertilizer to the planting hole beforehand. But mix it with soil before putting the plant in to prevent root burn.
- Place the root ball level with the ground, and backfill the with soil.
- Water deeply, and keep an eye on it for the first weeks until established (new growth appears).
How to space lettuce?
Spacing lettuce depends on its type. Head lettuce needs six to eight inches of space to form heads. For loose-leaf lettuce, no need to worry about it since you are going to harvest the leaves.
How to water lettuce?
Lettuce does not tolerate dry soil. Keep watering regularly allowing the soil to slightly dry in between. Since it is the cool season, rain might be enough to water your lettuce.
How to fertilize lettuce?
Lettuce is a leafy vegetable that needs a fertilize rich in Nitrogen-rich. If you check the fertilizer label, there are three numbers representing the concentration of the main nutrients. The order is Nitrogen, Phosphorus, and Potassium.
For lettuce fertilizer, the first number, Nitrogen, should the higher than the rest. You may also use fish-based fertilizer or seaweed.
What is the difference between head and leaf lettuce?
Head lettuce is the one you grow to harvest a whole head at once. Leaf lettuce is the one you harvest the leaves without pulling the whole plant.
How to harvest lettuce?
Depending on the variety, either pick the outer leaves for the leaf lettuce or cut the head at the base with a sharp, clean knife.
What is Cut-and-Come-again Technique?
Cut-and-come-again is a harvesting technique that extends the life of the crop. It is mostly used on leafy greens.
Why is my lettuce bitter?
Lettuce secretes a bitter substance as self-defense from predators. It allows us to grow a flower stalk (bolting) to produce seeds. This is the way it keeps the variety alive.
However, this survival is triggered when the temperatures are high, or water is scarce. Try to grow a variety that does not bolt easily, and keep it watered regularly.
How to protect my lettuce from pests?
The main enemies of lettuce are slugs, snail, and rabbits. Use an organic base bait called Sluggo to eliminate the slugs and snails.
A milder approach is to set traps around the lettuce plants. Fill a tuna can with a sweet drink, such as soda, sink it in level with the ground. The next day it should be filled with drowned slugs and snails.
As for rabbits or rodents, use a mesh cover or netting to keep them from eating the lettuce. You may also consider an animal barrier cage made out of steel cloth.
Can lettuce handle frost or freeze?
Lettuce grows in the cool season and withstands temperatures as low as 20F (-6C). But in case of a lingering hard freeze, it is best to protect it with a frost cloth.
What does regrowing lettuce mean?
Regrowth is when a plant sends new green growth when the root ball is left in the soil or water. Some vegetables, such as lettuce, can do so when you cut the head and leave the roots untouched.
It is a fun experiment to do with kids, but I would not rely on it for a sustainable harvest. The second growth tends to be weaker and thinner. If trying to have a continuous harvest, I suggest using the cut-and-come-again harvesting method.