Lettuces are broken down into four basic types: Romaine, Crisphead, Butterhead, and Leaf lettuce. Romaine tends to be a favorite, because of flavor. Crisphead is your closely packed lettuce head, like Iceberg lettuce. Butterhead is more loosely packed than a crisphead, and have a “buttery” flavor. And Leaf lettuce is the favored lettuce of home gardeners, because it grows quickly.
Popular lettuce varieties for each type of lettuce:
Dark Green Cos, Green Towers, Ideal Cos, Parris Island Cos, and Valmaine.
Great Lakes, Ithaca, Onondaga, Mesa 659, Raleigh, and South Bay.
Bibb and Salad Bibb, Buttercrunch, Dark Green Boston, Ermosa, Esmerelda, Nancy, Summer Bibb, Tania, Tom, and Thumb.
Black Seeded Simpson, Grand Rapids, Lollo Rosso, New Red Fire, Green Ice, Red Sails, Oak Leaf Lettuce, Prizehead, Ruby, Sierra, Slobolt, Tierra, Salad Bowl, and Waldmann’s Green.
Preferred Growing Conditions
Lettuce is a cool season crop. It produces well when lows and high temperatures are between 40 and 60 degrees Fahrenheit, respectively. So, really, lettuce makes for a good early spring and fall crop.
Soil conditions for growing lettuce should be high in organic matter, and a pH around 6.5. Sandy, and loamy soils are the best soils for lettuce. Lettuce has shallow roots, so it’s important the soil stays moist.
How to Plant Lettuce
Lettuce takes up very little space in the garden. Also, makes a great vegetable for container gardening. Timing is important to remember when planting lettuce. Remember, it’s not going to do well in the heat, unless it’s a heat tolerant variety. Plant lettuce early, or wait until the fall.
Most lettuces grow well from seed. Lettuce seeds can be broadcasted, planted by dispersing over a fixed area, or planted in rows. For rows, plant seeds about every inch, in 10 inch wide rows that are 18 inches apart. Cover with about ¼ inch of soil. Seedlings will need to be thinned, so they have 4-8 inches between them. Give Butterhead lettuce and Romaine lettuce plants 8 inches between each lettuce plant. Head lettuce varieties will need 12 inches between them.
So, most lettuces grow from seeds, but not head lettuces. Head lettuces grow better from transplants. Growing transplants from seeds takes about 11 weeks. To get a jump start on the lettuce growing season, you’ll need a greenhouse, or something, as simple as, a coldframe. Or just buy prestarted plants, if you wish to grow head lettuces.
Remember to replant lettuce every three weeks! It’s called succession planting, and spreads out the harvest. Here’s more information on succession planting.
Companion Plants for Lettuce
Growing these companion plants around lettuce plants will be helpful: Radishes, beans, and carrots.
Some plants actually are bad to the health of lettuce plants. Avoid these plants around lettuce plants: celery, cabbage, cress, and parsley.
Maintaining Lettuce Plants
Lettuce needs a lot of water, about an inch a week. You know, lettuce itself is 90 percent water. Mulch will help keep the weeds out and maintain moisture in the soil. Spread out a good layer of mulch around the lettuce plants, about 3-4 inches deep.
When to Use Organic Fertilizer
Did you add compost to your soil? If so, you might not even need a fertilizer. Just use some mycorrhizal root builder to help the roots absorb the nutrients already in the soil. If you want to try an organic fertilizer, try some fish meal. You can use fish meal or fish emulsion once every two weeks, if you use it sparingly.
Lettuce, like summer squash, needs to be harvested early. The larger lettuce grows, it will become bitter and tough. So, grab it out of the container or vegetable garden while it is tender. Keep an eye on it around 60 days after planting for transplants, and 80 days after planting seeds. It should be ready then for harvest, depending on the weather.
Harvest Tips for Lettuce Varieties:
Romaine and Butterhead Lettuce
Two ways to harvest these guys. Pick the outer leaves. Or, if you want another crop, harvest the whole plant by cutting it 1 inch above soil. Sometimes, it will grow again. Who doesn’t like a two for one deal?
Pick the outer leaves, only. The lettuce plant will keep growing. Leaf lettuce leaves can be picked when they are 2 inches long. Any smaller than that, and they won’t have much flavor. Harvest the whole plant when it has 4-6 inch leaves. Any bigger than that, and they will be too bitter.
Harvest full lettuce plant. You can use a knife and cut at the base of the head of lettuce. But, wait until the center of the head of lettuce is firm and crispy.
Lettuce Pests and Diseases
Slugs love lettuce, and lettuce gives lots of places for slugs to hide. The easiest way to spot a slug is to look for a glittering slug trail. That’s usually my first sign that slugs are making their way to my vegetable plants. Just don’t dump salt on them! It’s gross and will mess up the balance in your soil. Be sure to check out some organic slug pest control products.
If the lettuce leaf tips start turning color, it could be the hot weather. Remember, it’s a cool season crop. Keep an eye out beetles, caterpillars, and aphids! They like to join the slugs on lettuce.
Bolting, premature production of flowers and seeds, is another common problem with lettuces. Check out this page for tips on how to handle bolting lettuce plants. It will ruin the flavor of the lettuce, so it’s a good idea to do what you can to prevent it.