Growing Romaine Lettuce From Seed to Harvest
Are you thinking about growing romaine lettuce this year in your vegetable garden? We have all the details you need to grow vibrant, lush heads of romaine lettuce right in your backyard.
Is it easy to had to grow romaine lettuce?
Growing your own romaine lettuce is easy and can provide harvests for months during the spring and fall. However, to grow lush and green romaine lettuce, the plants will need partial shade, moist, fertile loamy soil, frequent light waterings, and bi-weekly fertilizer applications to thrive.
Choose The Romaine Leaf Lettuce Variety You Want to Grow
What is romaine lettuce?
Romaine lettuce, or cos lettuce, is leaf lettuce with crisp, sturdy leaves used as a base for salads. Although it is more heat tolerant than other lettuce types, romaine is still a cool-weather crop.
There are two different types of romaine lettuce, green and red:
Green Romaine Lettuces
For green varieties, look for:
Parris Island Cos – Paris Island Cos is one of the most popular romaine lettuce varieties with sweet tasty crisp leaves.
Little Gem – Little Gem is small, quick maturing romaine lettuce, the perfect size for a personal salad. We grow Little Gem every year, and it is by far one of our favorites.
Little Caesar- This lettuce produces tasty green outer leaves with golden blanched inner leaves that taste best when picked just before eating.
Red Romaine Lettuces
Red romaine lettuce tends to be green dotted with red, the color doesn’t change the flavor or the tolerance, but it does add a pop of color to salads. It also looks lovely growing in the garden. But some varieties are almost pure red (or wine) colored.
Gabriella Lettuce – Gabrialla lettuce is a deep red wine variety.
Rouge D’hiver – Dark red leaves that look beautiful in a lettuce garden.
Petite Rouge – Baby red romaine with red-tinged green leaves. Petite rouge is a great companion for Little Gem in the garden. Alternating the plants adds a bit of visual interest to your garden beds and rows.
In a hot weather zone, look for bolt-resistant lettuce cultivars.
Romaine lettuce is sometimes tricky to grow in the heat. For heat-resistant types of romaine, look for varieties such as Jericho and Coastal Star.
Choose One of Three Methods to Start Growing Romaine Lettuce Plants
You can start romaine lettuce indoors to give you a head start on the season, direct sow seeds in the garden, or buy starts from the garden center.
Start Growing Romaine Lettuce Seeds Indoors 4-6 Weeks Before Your Last Frost Date
You can grow romaine lettuce under grow lights indoors, but they will need to be on for 12-14 hours a day to provide the right level of sunlight to get a good start.
Use 1-inch seed starting cells and sterile seed starting mix for your romaine lettuce. Lettuce seeds should be planted 1/4 inch deep.
It is essential not to use garden soil or previously used potting soil for your seed starts. Garden soil is too heavy and can contain soil-borne diseases and insect larvae.
Potting soil can be too rich for baby seedlings. Start with a good seed starting mix, like pro-mix, to grow healthy, robust seedlings.
You will need to harden off your seedlings before planting them in the garden. Hardening off slowly allows the plants to acclimatize to the outdoor environment.
You will also need to harden off in stages, starting with one hour a day in the shade and gradually increasing the time spent outdoors until the plants can be outside full time.
Seedlings will emerge in five to ten days.
Direct Sow Romaine Lettuce Seeds Outdoors
I find it much easier to grow romaine lettuce directly into the garden. It is one vegetable that grows well from direct seeding, which frees up space in my indoor plant nursery.
Sow romaine seeds about a half-inch apart in seed trays or cells. You will want to cover the seeds lightly and gently water them to avoid displacing seeds.
When the seedlings reach an inch tall, you can thin them 5-6 inches apart.
Find Romaine Seedlings at Your Local Garden Center
You can pick up romaine lettuce seedlings at most garden nurseries at the start of the growing season.
Starts are usually very inexpensive to purchase and will benefit anyone who does not want to start seeds indoors but does want to get a jump on the season.
The only disadvantage to buying romaine seedlings is the selection. Greenhouses often only sell popular varieties, and if you want to grow something a bit different, it could be hard to find.
Plant fall lettuce in hot weather zones
Fall-planted crops benefit from having less insect pressure and tend to avoid diseases that crop up mid-summer.
In mid to late summer, you can plant seedlings or seeds for a healthy, robust lettuce crop in the fall.
Next, Plant and Grow Romaine Lettuce In Fertile Soil
Plant Romaine lettuce in loamy soil that has good drainage. The soil will also need a continuous supply of moisture.
Planting Romaine lettuce in soils with neutral pH ranging between 6.0 and 6.5 produces the best results.
Plant in Partial Shade
Does romaine lettuce require full sun?
You will want to avoid growing romaine lettuce in full sun. Although romaine is one of the more heat-tolerant lettuce, it will still turn bitter and bolt at high temperatures.
Plant romaine in a location with partial shade for best results.
Learn More: There are many vegetables you can grow in the shade alongside your lettuce, see our list of 28 shade vegetables for information and inspiration.
Provide at Least One Inch of Water A Week
How much water for romaine lettuce plants?
Romaine lettuce should receive an inch of water a week. Several light waterings a week are better than one single deep watering. You want to keep the soil moist but not waterlogged.
In hot, dry weather, you may need to water more frequently.
Fertilize Your Romaine Lettuce Every Two Weeks
Your romaine plants will require fertilization as they grow. Romaine lettuce is cut and come again, meaning you can continue to harvest leaves, and the plant will continue to send out new leaves. But for the plant to thrive, it will require additional fertilizer.
Feed your romaine plants every two weeks with a balanced granular or water-soluble fertilizer such as 5-5-5- diluted to half strength.
Consider Adding A Few Companion Plants
Companion planting brings a wealth of benefits to the organic garden:
First, they can help attract beneficial pollinators: Planting bright-colored flowers with abundant nectar and pollen will help encourage pollinators to visit your plants.
They will also attract many beneficial insects: Flowers and herbs will also attract predatory insects such as hoverflies, parasitic wasps, ladybugs, spiders, ground beetles, and lacewings.
Companion plants can help deter pests: Plants like garlic, chives, and onions can help repel common insects, such as aphids, cabbage worms, carrot rust fly, and beetles.
Companion plants can also help aid with weed control. For example, densely planted romaine lettuces can act as a mulch to shade weeds out.
And lastly, companions in the garden can help prevent the spreading of diseases in your garden: Diseases spread quickly through gardens when mass plantings of the same family are planted together. So it’s best to diversify your garden with smaller plantings.
Good companions for romaine are carrots, dill, cucumbers, onions, radish, spinach, squash, strawberries, and all cabbage family members.
- Learn More: If you want to learn more about companion planting, check out our beginner’s guide.
- Lettuce Companion Plants: What to Grow With Lettuce?
Manage Pests Quickly
Many pests will want to feast on your lettuce plants.
Small mammals like rabbits can mow down lettuce plants in a single night, and pests like aphids, beetles, cabbage worms, slugs, and snails will do the same if allowed to populate.
The best way to protect your lettuce plant from pests is to use a row cover at planting. A row cover will prevent pests from getting at the lettuce and provide much-needed shade.
You can also wait and plant your lettuce in late summer for a fall harvest. Late-grown romaine plants have much less insect pressure during that time of year as most cycles of insect growth have stopped or slowed.
Deal with Diseases as Soon as Possible
Diseases usually find a way into plants through stress. If the environment isn’t right, insects and diseases will follow if the plant isn’t receiving all it needs to thrive. The best line of defense against diseases is implementing good planting strategies.
Overwatering is the primary culprit of disease for many romaine plants, so only lightly water, and plant your romaine in well-draining soil.
The diseases most commonly found in lettuce plants are bacterial leaf spot, bottom rot, downy mildew, and Lettuce Mosiac Virus.
Harvest Romain Lettuce So It Keeps Growing Back
You can harvest the entire head of romaine when mature or use the cut and come again method where you can gather but still regrow romaine leaves to harvest later. A small lettuce crop of romaine can provide salads for many months.
How do you Harvest and Regrow Romaine Lettuce?
Before your romaine plant reaches maturity, you can harvest the outer leaves at any time. This harvesting technique allows you to cut the amount of lettuce you need while leaving the plant to continue producing leaves.
How long will romaine lettuce stay fresh in the refrigerator?
About 7-10 days.
To get the maximum shelf life you can for romaine lettuce, place it in the refrigerator in a plastic bag.
Do not wash romaine lettuce until you are ready to use it in your cooking.
Growing Romaine Lettuce isn’t Hard!
Growing lettuce is incredibly easy and is one of the best beginner crops to plant. Planting lettuce can even be done indoors or in containers for year-round harvests.
If you’re interested in vegetable gardening, we have many free guides to get you started. Check out these articles for inspiration: