How to Plant and Grow Lentils

Like many other crops, lentils have been grown for thousands of years and have been spread from their native Mediterranean to most countries throughout the world. The edible seeds of lentils are commonly referred to as pulses and contain high amounts of vitamins, minerals, protein, and fiber. And lentil plants themselves have the ability to improve the soil by adding nitrogen to it through their roots. Use this guide to plant, grow, and harvest lentils in your own garden.

Where to Plant Lentils

Lentils can easily be grown in gardens or even in pots due to their quick growth rate and small size. These hardy plants aren't too picky about soil types, but do require good drainage. They also need a spot where they'll get lots of sunlight and won't have to compete with other crops and weeds. Because of their small size and low yield per plant, it is a good idea to plant a large patch of lentils. 

As with other legumes, planting lentils near alliums such as onions, garlic, and chives should be avoided because they tend to build up sulfur in the soil, which in large enough concentrations can inhibit the growth of lentils. 

How and When to Plant Lentils

In warmer climates, plants are typically grown fall through winter while in colder climates, seeds can be sown in spring prior to the arrival of summer heat. Seeds should be sown directly into the garden about two to three weeks prior to the last frost date for your area. Seedlings are resistant to cold temperatures and frost, so planting too early is not usually an issue. In contrast, planting too late can hinder the growth of plants and cut down on production.

To sow lentil seeds:

1. Prepare garden soil by removing all weeds and other potential competitors.
2. Inoculate lentil seeds with Rhizobium leguminosarum prior to planting by lightly wetting seeds and sprinkling the bacterium so that all seeds are lightly coated. 
3. In rows at least 12 inches apart, push 1 to 2 lentils into the soil about 1 inch below the surface. Give about 5 inches between each planting to allow for good air circulation around plants as they grow.
4. Water soil and keep moist until seedlings begin to appear within about a week. 

Care Tips for Lentils

Light

Lentils require full sun (8+ hours per day). In less light, the plants may become leggy and won't produce as many flowers.

Soil and Water

Lentils can grow in loamy, sandy, and even rocky soils, thanks to their symbiotic relationship with bacteria that help them pull nitrogen from the air. Compacted soils can be improved by applying compost prior to planting. Watering should be even throughout the growing season but allowed to drain and dry thoroughly between applications to avoid waterlogging the soil, which can lead to root rot and other issues. Once pods begin to turn brown, stop watering so that plants can begin to die back and dry out prior to harvest. 

Temperature and Humidity

Lentils grow well in cool weather and begin to suffer in higher temperatures. Likewise, lentils prefer lower humidity levels, and stagnant, humid air can cause outbreaks of various types of fungal infections.

Fertilizer

Heavy applications of fertilizer are not necessary for these legumes and inoculated lentil plants will survive in even nutrient-poor soils. However, yields can suffer in poor soils. Adding a light dose of nitrogen fertilizer can be helpful in this case.

Pruning

Lentil seedlings can be pruned along the central lead to encourage bushier plants, but this is not necessary and can lead to excessive growth that blocks airflow and increases the risk of fungal infections. 

Pests and Problems

Lentils are exceptionally hardy but can be prone to fungal infections from high humidity, root rot from excessive watering, and insect pests such as aphids. 

Fungal infections can be treated by thinning plants to increase airflow and by applying organic fungicides such as neem oil and copper spray. Treat insect pests with insecticidal soap. 

Harvesting Lentils

Lentils can be harvested when the pods at the base of the plant begin to turn brown. Stop watering plants and allow them to dry further. When plants have begun to wither, they can be harvested by grabbing the base of the plant and pulling directly from the soil as a whole. Care should be taken not to break apart pods and lose the seeds inside. 

After harvesting plants, place them on a table or upside down in a bucket. Place drying plants in the sun or a well-ventilated room for about one week until plants have fully dried. Harvest pods and seeds from plants by plucking them by hand and splitting them open over the bucket, or thrashing the plants inside a bucket. Separate out the leaves and other debris from the lentil seeds by shaking the bucket until the lighter stems and leaves to move to the top, where they can be removed. 

How to Propagate Lentils

Lentils are annual plants grown from seed. Harvested lentils can be saved and stored in a cool, dry location for planting the following season. Due to a low incidence of cross-pollination, different varieties of lentils can be planted near each other without contaminating gene pools, as often happens with other garden plants such as corn or squash.