Lettuce, the main ingredient in many salads, is an easy and versatile vegetable. It can be used as the main meal or as a side dish…and it doesn't require cooking. What could be better!
In a recent issue of The Packer (April 2009) it was reported that lettuce purchases were up in 2009, and Midwesterners were the biggest buyers. Lettuce purchases were analyzed with respect to a purchaser's income, age, and gender. More than half of all people surveyed were purchasing lettuce. (If you are a female, or 40-49 years of age, or have an income of greater than $100,000 per year – you might be purchasing more than other demographic segments.)
Lettuce is also fairly easy to grow. Seeds can be sown directly in the garden in spring and again in late -summer. If the soil is kept moist, seedlings should emerge within 7 to 10 days.
There are 4 distinct groups of lettuce; crisphead, butterhead, romaine, and leaf.
Iceberg is a popular cultivar of crisphead lettuce. They form tight, firm heads with crisp leaves. Unfortunately, crisphead lettuces are heat sensitive and are difficult to successfully grow in Iowa. Planting in early spring is best, so that the heads can mature before the onset of hot weather. Seed is generally sown in rows and plants are thinned to 12-14 inches apart. 'Ithaca' and 'Great Lakes' are two cultivars suitable for Iowa. Plants are harvested when the heads are mature, usually 70-80 days after sowing.
Butterhead, or bib, lettuce types also form heads, but they are smaller than crisphead lettuce and the leaves loosely fold over one another. Because the inside leaves receive little light – they are often cream or "butter" colored, hence the name butterhead. Sowing and spacing is the same as crisphead types. Gardeners can harvest the outer leaves or immature heads or allow the plants to fully mature (approximately 70 days after sowing). 'Buttercrunch', 'Summer Bibb', 'Red Cross' (red leaves), and 'Speckles' (speckled leaves) are cultivars recommended for Iowa gardens.
An upright form of lettuce that is increasing in popularity is Romaine or cos lettuce. Romaine lettuce leaves are typically firmer in texture and often sweeter in taste compared to other types. The leaves reach 8-10 inches tall and are tightly folded to form a narrow, upright head. The outer leaves can be harvested throughout the season, or the entire head can be harvested approximately 70 days after sowing. Some cultivars worth trying include: 'Green Towers', 'Green Forest', 'Parris Island', 'Cimarron' (red leaves), 'Rosalita' (red leaves), and 'Flashy Trout's Back' (speckled leaves).
The fourth type, leaf lettuce, offers the widest variety of leaf shapes and colors. Leaf lettuce also matures earlier than the other types – generally in 40-45 days. Because leaf lettuce does not form heads, they are spaced closer than the other types, usually 4-6 inches apart. Seeds can be sown in rows or scattered in a large block, making efficient use of garden space. The economy of space, diversity of leaf shapes and colors, and early maturity contribute to its common use in the home garden. A few recommended green leaf cultivars are: 'Black seeded Simpson', 'Envy', 'Grand Rapids', 'Oakleaf', and 'Tango'. A few recommended red leaf cultivars are: 'New Red Fire', 'Red Sails', 'Red Salad Bowl', 'Ruby', and 'Vulcan'.
Red Cross Butterhead Lettuce: Photo by Cindy Haynes 
Rosalita Romaine Lettuce: Photo by Cindy Haynes
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