Lettuce is a cool weather crop that we can start early in the season and harvest throughout the entire season. We look at how to grow romaine lettuce in any garden.
Growing Romaine Lettuce
One of the most popular varieties of lettuce is Romaine (Cos). The heads are full of beautifully large leaves. Used for Caesar Salads and can be harvested by the leaf or full heads. You can grow Romaine Lettuce in all growing zones 1 through 9.
Not sure which zone you garden in? We have a detailed post on Growing Zones in Canada.
Where To Grow Romaine
Like all varieties you have many options when selecting a location to grow Romanie. Even the tiniest gardens can successfully grow these robust heads. Container growing is a great option for those with limited space or for those who prefer to control where their gardens grow.
In ground planting is a great choice for succession planting which will give you a perpetual harvest. With scheduled planting you can harvest fresh romaine the entire growing season. For season long harvests select a shaded growing location. This helps in protecting it from the hottest days of summer.
How To Plant Romaine
Romaine can be started early in the season under lights a few weeks before the final frost of the season. It can also be started in cold frames during this period.
Start the seeds in potting soil filled growing cells at a depth of a ¼ inch. Water lightly and cover the trays with a lid. Place in a warm location until the seeds germinate. Once the romaine has sprouted, place the tray under lights or in a sunny location. Once the seedlings are an inch tall, they can be hardened off before being moved into the garden.
Hardening Off Indoor Started Plants
Hardening off is the process of setting seedlings outdoors in a sun and wind protected area daily for 2 weeks to condition the plants to the outdoor environment. Simply start by placing the seedlings outdoors for an hour or 2 and extending their time outdoors and hours or 2 everyday, weather permitting. After 2 weeks the plants will be ready to be transplanted outside.
Planting Romaine Lettuce
Work the soil well, adding amendments like peat moss, compost and sand if needed. Sand aides in drainage and is a good addition if your garden soil is compact. If planting in rows, space the seeds ¼ – ½ inch deep, spacing the seeds ½ inch apart in rows 12 inches apart. Add a row every second week for a continual harvest.
If planting in beds, space the seeds ½ inch apart. You can stagger the plants for a nice full bed. Grow Romaine alongside other types of lettuce, vegetables or even flowers.
For container gardens, space the seeds out ½ inch apart in the chosen planters. Be sure to use potting soil which you can buy at greenhouses and garden centers for container gardening. It is lightweight and the preferred growing medium for planters. Soil from the garden will compact in planters restricting root growth and plants will not perform well. Be sure all containers have adequate drainage holes.
To plant transplants, make the planting hole slightly larger than the root ball. Place the seedling in the hole and lightly tamp down the soil to keep the transplant in place.
Water all plantings lightly, not allowing the soil to dry out between waterings. Seeds will germinate in 7 – 10 days. If the plants are crowded, thin every second plant out once the leaves are big enough to be enjoyed as baby lettuce.
Once the seedlings are up you can mulch the beds or rows to help reduce weeds and conserve moisture.
Succession Planting
When growing Romaine lettuce, we can utilize succession planting. That is the practice of planting new plants every 2 – 3 weeks. This can give you a perpetual harvest of fresh romaine for the entire garden season. When romaine ages out in the garden it will begin to bolt, once this happens it is no longer good to eat and can go into the compost pile. Succession planting assures you will always have fresh romaine available.
Caring For Romaine
Like all lettuce, romaine is easy to care for. Water as needed, not allowing soil to dry out between waterings. Use a gentle hand when weeding as the roots of romaine are fairly shallow.
Harvesting Romaine
You can begin to harvest romaine leaves as soon as they are around 2 inches tall. Only harvest a few leaves from each plant when they are young to encourage the heads to continue to grow.
Using your fingers pinch the base of the leaf to remove it from the growing plant. Be gentle so as not to disturb the roots. If harvesting plants to thin the rows, remove the entire plant including the roots.
Harvest heads once they reach 8 inches in height and are starting to fill out. Grasp the head in your hand and using a sharp knife cut the head away from the base, leaving about an inch attached to the roots. The trimmed base will continue to grow sprouting baby lettuce leaves.
Storing Romaine
Lettuce generally has a fairly short storage life. Refrigerated as soon as possible after harvest. Place whole head into plastic grocery bags and stored in the fridge. Wash it well before eating.
Another option is to wash the leaves and place them onto a paper towel. Roll the paper towel up and place the entire roll into a plastic bag before placing into the fridge.
Use within a week for optimal freshness.
Be sure to check out this earlier post on How to Plan and Grow a Salad Garden. It has great growing tip and a variety of salad greens to choose from.
