Sometimes, the variety of the lettuce you want to grow may not be available in your local nursery and your only option is to grow your lettuce from seeds.
One of the common questions from those who are growing lettuce from seeds is, “When do I transplant my lettuce seedlings into my garden?” After growing lettuce for the past 8 years, here’s what I know when it come to transplanting it:
You should transplant lettuce seedlings when they are between 2 – 4 inches tall. Make sure the seedlings are hardened 5 – 10 days before transplanting them from the pots to outside gardens or raised beds.
Truly, knowing when to change growing environment and medium for lettuce seedlings is crucial to their growth and development later on.
To help you get started, this post will guide you the right way on when and how to transplant your lettuce seedlings.
Lettuce, Lactuca sativa, is a hardy, cool-weather crop. It is a perfect crop for cool-season gardening. There are several varieties of lettuces to choose from. You can decide to row the loose leaf mixes, Bibb, Romaine, Crisphead lettuce, and so on.
Plant your lettuce seeds in flats or soil blocks of moist, quality potting mix. Keep the nursery bag or pot somewhere cool at least until the seeds germinate. Once your lettuce plants germinate, place them under lights or somewhere they can get direct sunlight.
It’s best to grow lettuce at a soil temperature range of 60°F to 65°F (16°C to 18°C). most lettuce plants germinate best at a temperature below 70°F (21°C). Lettuce seeds can enter thermal dormancy when exposed to high temperatures.
If your region is hotter, you need to carefully choose a lettuce variety that can withstand hot conditions for success in hotter weather.
Reasons for Transplanting Your Lettuce
Transplanting refers to the act of moving seedlings or small plants from their nursery bed or pots into the direct garden soil. This applies to both:
- Small starter plants, known as “transplants,” sold at the nursery. Growing some vegetables from seed is so challenging (or may take too long). In such a case, you should rely on the nurseries to grow those plants. Examples include tomatoes, peppers, eggplant, and so on.
- Young plants grown from seeds at home. You may choose to start plants from seed indoors to get a jump start on the season, especially if you live in a region with a short growing season.
If you’re growing a heading variety of lettuce, you may want to consider starting your lettuce indoors and transplanting seedlings out.
When to Transplant Lettuce Seedlings
Lettuce is a cool-season crop and should be planted before outdoor temperatures get too warm. It is best to transplant lettuce in the spring and fall in most regions.
The planting calendar above shows when to transplant your lettuce based on your local frost dates.
Direct sowing into the garden soil is ok as soon as you have worked the ground. However, if you want an earlier crop, you can grow the lettuce seeds indoors four to six weeks before your last spring frost date. Some lettuce seedlings will even tolerate a light frost.
Grow your lettuce seed after the soils reach 40°F (4°C). Though the seeds would germinate best at a temperature between 55°F to 65°F (13°C to 18°C). Seedlings will typically emerge after seven to 10 days.
Transplants bought from the nursery should be transplanted near the last frost-free date for the growing area.
Seeds that were gown indoors may be planted two to three weeks earlier after they are properly hardened off.
Lettuce should be transplanted when the plants are between 2-inch to 3-inch tall.
After you have transplanted your lettuce seedlings, sow additional seeds every two weeks to have a continuous supply of lettuce. In some regions, it’s possible to grow a second crop of lettuce in the fall or even early winter.
Important note: To plant lettuce in the fall, you need to create cool soil in August. You can do this by moistening the ground and covering it with a bale of straw. After a week, the soil under the bale would be about 10°F (6°C) cooler than the rest of the garden.
Then plant a 3ft row of lettuce seeds every couple of weeks – just rotate the straw bale around the garden.
Preparing A Planting/Transplanting Site
For the best growth, choose a sunny spot. Let your lettuce get at least six hours of sunlight every day, though lettuce will still grow if given less than that amount of sunlight. Make sure that the soil is loose and drains well so that it would get moist without staying soggy.
To keep the soil fertile, work in organic matter or compost about a week before you plant seed or transplant. If available, you can use NPK 10-10-10 fertilizer instead to improve nutrient-deficient soil. Use chemical fertilizer at a rate of two pounds per 100 sq. ft. of area.
Remove stones and large clods of dirt as they may inhibit germination. Lettuce doesn’t compete well with weeds. So try as much as possible to remove weeds from around your lettuce plant. Also, planting lettuce close together will help to control weeds.
How to Transplant Lettuce
Lettuce seeds should be planted one-eight (⅛) to a quarter (¼) inch deep into the soil. Lettuce seeds need light to germinate, so don’t sow them too deep into the soil. You can thin the lettuce seedlings when they have three to four true leaves.
Wait till the lettuce seedlings have about four to five mature leaves and a well-developed root system before you transplant them into the garden soil. Whether seeded or transplanted lettuce, leave about 12in. to 15in. between each planting row.
Water thoroughly while transplanting your lettuce. You may plant rows of chives or garlic in-between your lettuce rows to control aphids. Chives or garlic acts as a “barrier plant” for the lettuce.
Here are planting guidelines for different lettuce plants:
- Loose-leaf lettuce: transplant or thin to 4 inches apart
- Romaine (cos) and butterhead (loose-head, Bibb, Boston) lettuce: transplant or thin to 8in. apart.
- Crisphead (iceberg) lettuce: transplant or thin to 16in. apart.
Generally, you should harden off your lettuce plants seven to 10 days before transplanting. Lettuce seedlings properly hardened at least three to five days before transplanting can survive temperatures as low as 20°F (-6°C).
Bring the lettuce plants outdoors for a few hours – increasing the length of time each day. Prepare your garden soil or bed by loosening the soil and adding compost if available.
Transplant your lettuce plant at the same depth as you did in the pot. Even if your lettuce plants look leggy, don’t bury the stem.
Lettuce stems don’t grow roots like tomatoes and some other plants. Water the lettuce plants after transplanting and keep the garden soil moist to get them established.
Fertilize your lettuce plant three weeks after transplanting. Lettuce plants prefer soil that is high in organic matters, has lots of compost, and a steady supply of nitrogen to keep it growing fast. Use organic alfalfa meal or a slow-release fertilizer.
Though Lettuce is a hardy, cool-weather crop, early and late sowings may need protection against cold.
This article has helped you to know when you should transplant your lettuce seedlings into the garden soil. It also covers how to prepare your garden soil in preparation for the transplant, and how to transplant your lettuce plant.
If you have any inquiries or suggestions, don’t hesitate to use the comment box below.