There are five distinct types of lettuce: leaf, Cos/romaine, crisphead (Iceberg types), butterhead, and Batavian/summercrisp.
Lettuce is a fairly hardy, cool-weather vegetable that thrives between 60 and 70°F. At high temperatures, growth is stunted, leaves are bitter, and the plant bolts. Some types and varieties of lettuce withstand heat better than others. The crispheads are slowest to bolt, then summercrisps, butterheads, leaf lettuces and finally cos types.
These are the varieties of lettuce I have in my collection, ordered by type:
Green Royal Oak: Early variety, tender and long standing. The leaves are heat resistant and dark green. Not bitter. 40 days
Black Seeded Simpson: A large upright, compact leaf-type lettuce with light green, wide, curled leaves. It is a very early, dependable and productive variety that is very heat tolerant and slow to bolt. Introduced in the 1870’s by Peter Henderson & Co. Sweet and tender leaves, light yellow-green, very popular. 45-60 days
Prizehead: Despite the name, it is a non-heading, leaf lettuce. Leaves are upright, deeply curled, broad and light green. Prizehead was named after the island off of South Carolina and released in 1952 by Clemson Agricultural Experimental Station and the USDA. 55 days
Cos or Romaine types:
Red Romaine (my hand collected seeds): Delicious, flavorful lettuce brings color and zest to salads. The red coloring develops best in cool weather.
Summer crisp or Batavia types:
Cherokee: F1 hybrid. Thick, crisp, dark red leaves with good flavor. Very slow bolting with excellent tolerance to heat and bottom rot. 48 days
Merville de Four Seasons (Marvel of the Four Seasons) or its true (french) name, Merveille des Quatres Saisons. Also (Italien) Quattro Stagioni. This lettuce seems to go by many names. I have two packs, each with different variations of the name. Merveille is an old French heirloom lettuce originally introduced commercially in 1885. It produces 8 to 12 inch heads. The leaves are a creamy yellow to light green color and are tipped with a beautiful reddish-bronze color on the outer leaves. For beauty, Marvel of the Four Seasons is one of the most striking and gorgeous lettuces available. Features an excellent flavor and does well in all types of climates. Can be sown spring and fall and is resistant to cold. 40 to 55 days
Burpee Bibb: Bibb owes its name to John Bibb who developed this variety in Kentucky from Boston lettuce in the 1850s. The Burpee catalog says this Burpee bred variety is the sweetest Bibb lettuce ever. Heads have tender, dark green outer leaves that are tinged with brown and creamy yellow inside. 75 days
Big Boston: You can tell Bibb lettuce from Boston lettuce because Boston’s leaves are wider and lighter green than Bibb. Big Boston has light green and brown-tinged leaves. This variety was apparently first offered in the US by Peter Henderson & Co. in 1890. Originally from France, it was renamed Big Boston by Henderson. 70 days
Fall greens mix (Sandhill Preservation Center): A mix of greens including lettuce, chards, greens, Chinese cabbage, spinach, and endive that is designed to be planted in the late Summer (early to late August here in Iowa) to be harvested from mid-September until the ground freezes.
Arugula (Eruca sativa)
Endive (Cichorium endivia), Blonde Full Heart: A popular escarole type and one of the few well known to American gardens. Elongated, non-heading broad leaves with a yellow heart have good flavor and color. This is a endive is adapted to a wide range of climates. 65 days
I plan to experiment with winter planting of lettuce ASAP in plastic bottles. My first garden planting will be March 20, I hope. Lettuce and peas will be my first vegetables planted in the spring garden.