Many gardeners who are familiar with the ease of growing leaf lettuce shy away from cultivating head lettuce. However, this plant can also be easy to grow, as long it receives the sunlight, water, and food it needs. Before attempting to grow head lettuce outdoors, though, gardeners need to wait until the temperatures average between 55 and 60 degrees each day. [photo via wikimedia]
Preparing the soil for head lettuce
As is the case with many vegetables, head lettuce needs soil with a pH level of at least 6.0 and no higher than 7.0 to ensure it gets adequate nitrogen. A simple way to cover this aspect of growing is to add a nitrogen-rich fertilizer to make up for any nutrient deficiencies in the soil. Loosen the soil well and add compost to give it a fertile environment for growing the plants.
How to plant head lettuce
If you intend to harvest head lettuce in the winter, you’ll need to plant it in the late summer or early fall. However, if you want to harvest it in spring, you can start it indoors toward the end of winter and then transplant it outside. For a spring planting, sow your seeds indoors about seven weeks before the last frost. Gradually harden them to the outside temperatures by increasing the amount of time they spend outside until they are accustomed to the environment. After about six weeks of this, they should be ready to transplant.
Create a planting space five inches deep for each lettuce plant and set them about 10 inches apart. Trim the outer leaves off each plant, leaving the middle intact. Set each plant in its own hole and lightly cover it with soil.
Caring for your head lettuce plants
Water the plants lightly to ensure that the soil remains moist. If you live in a climate that receives at least an inch of rain per week, you likely won’t need to water the soil yourself. You can measure your rainfall easily by placing a rain gauge in the garden. Add mulch to the soil often so that it stays cool and avoids drying.
Keep an eye out for weeds that may grow around the roots and remove them by hand. Lettuce is vulnerable to aphids, so look for an organic pesticide or add some ladybugs to the garden to get rid of them.
How to harvest head lettuce
You may be picturing the ideal globe-size head of lettuce when you think about harvesting. However, you’ll need to begin harvesting these plants long before they reach that size. When your first head of lettuce reaches the diameter of a softball, start harvesting right then. This way, you’ll avoid having to harvest them all at once. Use a knife to cut the head off at the soil line and store it in the refrigerator until ready to eat.