How to Grow Lentils

Like many plants, the lentil (Lens culinaris) gets its name from one of its prominent features, in this case the lens shape of the seeds. A member of the legume family, the lentil plant grows as a bushy annual plant in all parts of the United States. It prefers cool weather and is an easy-to-grow plant that needs only a bit of care now and then to thrive.

Lentils need 80 to 110 days to produce a harvest, so it's helpful to plant seeds in the garden in early spring. However, seeds also need a soil temperature of at least 41 degrees Fahrenheit to germinate. If spring is cool where you live and your soil warms slowly, it helps to start seeds indoors so that there's sufficient growing time outdoors to produce a crop.

Sow seeds in potting soil or a soilless mixture several weeks before your last expected frost, using flats or small pots; keep these around 68 F, a temperature at which lentil seeds germinate in about 10 days. Once they emerge, set the seedlings in a sunny indoor spot and keep the soil evenly moist until danger of frost has passed and you can plant them outdoors.

Lentil plants grow in any type of garden soil provided it drains well and is free of weeds that will compete with the lentils. If your soil tends to drain slowly because it's high in clay, improve its drainage by mixing in about 2 inches of coarse sand with a garden fork before planting. At the same time, add about 2 inches of aged compost to your planting site to raise the soil's content of organic matter and boost its fertility.

Trowel

Garden shears

Soaker hose or other watering system

Compost tea

Choose a spot that warms quickly early in the season -- for example, on a slope that faces south and east -- and gets full sun for most of the day.

Dig a furrow about 1/2 to 1 inch deep with a trowel if you plan to direct seed. Plant lentil seeds about 1 inch apart, and cover the seeds. Later, thin the seedlings with garden shears so that they're 4 to 5 inches apart.

When thinning plants, don't pull out extra seedlings to avoid damaging roots on the plants you keep. Instead, cut extra seedlings off at soil level with shears, cleaning the blades by wiping them with rubbing alcohol between each cut to prevent the spread of diseases.

Use a trowel to dig a series of holes if planting seedlings. Set the seedlings about 4 inches apart, keeping each plant at the same level as it was in its flat or pot.

Keep lentil plants evenly moist, providing extra water whenever the top inch of soil is dry to the touch. Once pods begin to dry late in the season, withhold water so that the plant can dry out.

To boost the plants' growth, feed them with compost tea when they're 5 inches tall and again at flowering. Pour the tea into a shallow furrow made with your trowel into the soil alongside each row, a practice called side-dressing.

Several lentil cultivars are available to plant in a garden, including the following:

'French Blue,' with lentils a bluish green color 

'Petite Crimson,' whose seeds are orange-red 

'Spanish Pardina,' with tan-colored lentils

Lentils grow as slightly branched vines that are 18 to 24 inches tall, so set a low supporting trellis along each row to keep the plants off the ground, which helps prevent fungal problems. Plants naturally attach to the trellis as they grow.

It is also helpful to keep the area free of weeds, starting early in the season, because weeds compete for soil moisture and nutrients. Hand-weeding can control weeds. Alternatively, you can add some straw under the plants to prevent weed growth, but keep the straw 1 or 2 inches from the center of each plant to discourage fungal problems.

Lentil plants are usually free of serious disease or pest problems, although they might attract aphids, small greenish insects that suck plant juices. Control these by spraying with insecticidal soap, diluted at a rate of 5 tablespoons per gallon of water; repeat every two weeks as needed.