Romaine lettuce is among the most common types of looseleaf lettuce used as salad greens and in sandwiches. Although lettuce is a trendy vegetable, it is also highly susceptible to food-borne illnesses during growth. You may find growing your lettuce to be the better option – this article has tips on how to plant romaine lettuce.
There are numerous lettuce varieties available globally, like crisphead, or as it is better known, iceberg lettuce, and romaine belongs to a lettuce category with loose heads like Bibb and butterhead lettuce. Due to its popularity and to keep up with demand, commercial growers dedicate thousands of acres to growing lettuce to keep your local grocery store stocked.
While it’s a reasonably inexpensive crop to purchase, you can save a few bucks and bring fresh homegrown produce to the table by knowing how to plant romaine lettuce on your own.
- Planting Romaine Lettuce Indoors
- When to Plant Romaine Lettuce Outdoors
- How to Plant Romaine Lettuce
- How to Plant Romaine Lettuce in a Hydroponic Garden
- Planting Romaine Lettuce Seeds for Microgreens
How to Start Planting Romaine Lettuce
Planting romaine lettuce is easy, and with simple care, your lettuce is ready for harvest. To get there, we’ll cover topics like how far apart to plant romaine lettuce seeds and when to plant romaine lettuce seeds for the best yield of leafy greens to fill your salad bowl.
Planting Romaine Lettuce Indoors
Lettuce plants are cool weather crops to plant in early spring or late summer. A good time to plant lettuce in zone 7 is to start your seeds indoors at least four weeks before transplanting them outside to their garden beds when planting in spring.
When planting romaine lettuce indoors or if you plant iceberg lettuce, location is crucial. Romaine lettuce thrives in an area that receives full sun for at least six hours during the day and partial shade the rest of the time.
There is a bit of flexibility in picking the pot or container for your lettuce as romaine grows in pots as small as four inches in diameter, but planting seeds in a larger pot allows you to harvest a larger head of lettuce.
When picking a pot, remember that romaine’s root system is made up of short but wide roots, so use a container that accommodates this. Fill your pot with mixes that are designed for seed-starters and keep the soil moist.
Romaine seeds germinate at temperatures between 40°F and 85°F, usually between five and ten days, but sometimes in as little as two days.
When to Plant Romaine Lettuce Outdoors
Four weeks after starting your romaine lettuce seeds indoors, or once several true leaves sprout, it should be time to begin transplanting them into your outdoor garden. Before you make the garden beds or raised beds your romaine’s new home, an essential step is to harden your seedlings.
To harden your romaine plants, bring the pots outside for one hour a day, adding one hour each day until your plants remain out for a full day of sunlight and overnight.
During this process, gradually provide them with more exposure to the full sun. Hardening is a crucial step for transplants as it allows your plant to acclimate to the conditions it faces while growing outdoors.
If you are starting your romaine plant outdoors from the beginning, whether from seed, scraps, or a seedling, wait until the last frost passes and the ground thaws to plant your romaine in the spring. Plant romaine in midsummer if you are planting romaine lettuce as a fall crop and looking forward to a late fall harvest.
Lettuce like romaine lettuce needs full sun to thrive so plan your crop accordingly.
How to Plant Romaine Lettuce
Water your seedlings well before transplanting to keep roots hydrated. Plant your seedlings 12 to 18 inches apart. Add a layer of mulch or organic matter compost to maintain the temperature and keep the soil moist after watering.
How to Plant Romaine Lettuce in a Hydroponic Garden
Growing hydroponic lettuce is an exciting way to grow your favorite produce in a controlled environment regardless of the growing season. Lettuce leaves become edible after three weeks, and in 40-80 days, the full head of lettuce is ready for harvest.
This quick growth means that with careful picking, you can harvest the outer leaves of your crop while leaving the center leaves, or the majority of the head alone, allowing it to grow new leaves and provide you with a continuous supply of leafy greens.
For DIY-inclined gardeners, crafting your hydroponic system is doable; however, many affordable systems are ready for purchase on the market. Other than your system, you’ll need a growing medium to place your romaine seeds in, and commercial growers recommend rockwool or stonewool due to its ability to hold water.
Rockwool has high pH, so testing beforehand is essential. If necessary, soak rockwool cubes in acidic water to lower the pH to 6.0 to 6.5 to make them suitable for your romaine seeds.
Lettuce has a high germination rate, and after planting your rockwool cubes, you should see sprouts in a few days. Once your seedlings have four to six true leaves and the roots are sticking out of the bottom of your medium, transplant them into your system, thinning as needed.
Planting Romaine Lettuce Seeds for Microgreens
Microgreens are various types of lettuce and other greens grown together in shallow containers that make harvesting easier. Microgreens are very simple to grow at home and create an interesting way to add more veggies into your diet.
To start, fill a shallow or wide container with good drainage with a potting mix. Lay your romaine or lettuce seeds on the surface of the mixture and cover with a fine layer of soil. Microgreens don’t require fertilizer but do need moisture, so mist your seeds with a spray bottle and place the container’s lid on to keep the water inside.
Leave the container in an area of your home where the daily temperature reaches at least 60°F with lots of indirect sunlight.
Once your seeds sprout to about two inches tall with mature leaves, they’re ready to harvest. Your microgreens don’t keep long and may wilt quickly, so gather as needed and wash thoroughly before consuming.
After harvesting your lettuce, you may not be able to eat it all at once. One of the ways to keep romaine lettuce fresh is to store it in a plastic bag with a damp paper towel and put it in the crisper drawer. It will last several days.
How to Protect Your Romaine While Growing
On your way to an ideal harvest, your romaine may face several challenges between pests and hot weather that threatens to bolt or wilt your crops.
Dealing with Bolting
While heat-tolerant romaine varieties such as Jericho, Annevue, and Craquerelle du Midi exist, romaine is considered a cold-season crop due to its tendency to bolt in warmer conditions.
Knowing when to plant romaine lettuce and when you harvest romaine lettuce helps avoid bolting as well; avoid planting on sunny days. Instead, save your lettuce seedlings for a cloudy day to avoid stressing your transplants.
When your crop reaches maturity, high temperatures and severe changes in daylight sun exposure cause your lettuce to bolt. Bolting involves your crop producing flower stalks to make seeds instead of leaves. While plants creating seeds is usually a good thing, it’s a bad sign with lettuce, a plant explicitly harvested for its leaves.
To prevent bolting, start by planting seed varieties known as slow-bolting, keep the soil moist, and plant in an area that receives shade during the day. Adding row covers made of cloth also protects young seedlings as it allows rain and sun to reach your plant while protecting it from intense UV rays.
Keeping Pests Away from Your Romaine
As much as you love romaine lettuce, harmful insects in your garden love it just as much. Caterpillars, slugs, and aphids are some of the more common pests you may find attempting to destroy your plant.
A simple solution to protect lettuce from pests is to allow their natural predators to feed on them. Birds prey on caterpillars, and beneficial insects like ladybugs and damsel bugs enjoy snacking on aphids for you. When you harvest any leaf lettuce, it’s important to watch for bugs before you bring the leaves indoors.
Repel snails and slugs from your garden by introducing beneficial companion plants like lavender and sage, which naturally repel slugs and snails.
If our tips on how to plant romaine lettuce inspire you to introduce romaine to your garden in a new way, share these tips on planting romaine lettuce on Facebook and Pinterest.