Lima beans, also known as butter beans and chad beans, grow much the same as green beans, although they tend to take longer to mature. The smaller varieties are quicker, which is why you see "baby" lima beans for sale more often than the larger beans; there's a quicker turnover.
Lima beans have the familiar bean compound leaves of three, or trifoliate, with oval leaflets that are about 2 to 3 inches long. Flowers are white or yellow and form loose clusters. The resulting pods are curved and flatter than common green beans. Lima beans have been cultivated in their namesake Lima, Peru, for over 600 years. All varieties are high in protein as well as several vitamins and minerals. They can be used fresh, frozen, or dried.
- Botanical Name: Phaseolus lunatus
- Common Name: Lima beans, butter beans
- Plant Type: Annual
- Mature Size: Bush variety, 2 feet tall; pole variety, 12 feet tall
- Sun Exposure: Full sun
- Soil Type: Moderately rich, well-draining
- Soil pH: Slightly acidic to neutral
- Harvest Time: Summer
- Flower Color: White or yellow
- Hardiness Zones: Not frost resistant
- Native Area: Mesoamerica and South America
How to Grow Lima Beans
There are bush and pole lima beans varieties. Like green beans, the bush types will begin setting pods sooner. Bush lima beans also tend to set their entire crop at once, so you will only be able to harvest from them for a couple of weeks. If you can succession plant a row every three to four weeks, you will be able to prolong the harvest season. You could also plant both a row of bush beans and a seeding of a pole variety. That way you can start the season with the early maturing bush beans and continue harvesting throughout summer from the pole beans.
You will need a spot with full sun to get the most from your Lima beans. They need warm temperatures and a long day length. Full sun will also keep the vines dry and less prone to fungal problems.
As legumes, Lima beans do not need overly rich soil or much supplemental fertilizer. The soil should be well draining and moderately rich in organic matter. Heavy clay soil can pose growing problems because lima beans have deep, expansive roots and do not like to sit in wet soil. Soil pH should be in the neutral range of 6.0 to 6.8.
Pole beans will need sturdy support. The vines can easily grow 10 feet or more and become heavy with pods. Plant 4 to 6 seeds on each side of a trellis or teepee. Bush types grow 2 to 3 feet tall and may need staking when they are covered in pods.
Keep the soil moist until germination, then make sure the plants get at least 1 inch of water per week. In hot, dry weather, water more frequently to keep the ground cool, and mulch around the roots. Pay extra attention once the plants are in flower and start setting pods; they will drop them if they experience drought at this point.
Temperature and Humidity
Lima beans can be a bit temperamental about temperature. They do not like extremes and grow best in climates that stay around 70 degrees Fahrenheit for several months. However, they can handle warm temperatures better than a prolonged cool temperature. Lima beans plants are not frost-hardy.
Legumes generally do not need extra fertilizer, especially if the soil is already rich. However, since Lima beans have a long growing season, it helps to give them a side dressing of compost or composted manure, or a dose of organic fertilizer, mid-season. These are slow releasing and will help the plants continue for the rest of the season.
Growing From Seeds
Lima beans have big seeds, and they can be direct sown 1 to 2 inches deep. Space bush varieties about 4 to 6 inches apart, although you could also scatter the seeds in a wide row and thin, if necessary.
If you have a short season and want to grow pole limas, consider starting the seed indoors 3 to 4 weeks before your last frost date in peat or paper pots. Or warm the soil in the spring with a layer of black plastic and then direct sow the seeds with some protection, like a row cover or a windbreak of plastic or straw bales, around the seedlings. The soil needs to be at least 65 degrees Fahrenheit for good germination. If you are not pre-warming the soil, wait for 2 to 3 weeks after your last frost date to direct seed.
Being Grown in Containers
Bush lima beans can be grown in containers, but you may need several containers for a practical harvest. Beans will grow in 8-inch containers.
There is wide fluctuation in the length of season needed to grow lima beans. Some bush varieties like Fordhook might begin producing in 60 days. The heat-loving pole beans, like Christmas lima, will not start setting pods until about 90 days. If you live in a short season area, these might not be the type for your garden. But you can always experiment and try starting the seeds indoors.
Begin harvesting when the pods feel full. They will not plump up like green beans, but you should still be able to see a slight bump. Hold the vine end when pulling off the pods or you could take a big section of vine with them.
Pests and Disease
The usual bean pests will seek out your plants. Heading the list are bean beetles and aphids. Keep watch and tackle any problems while they are small. Many four-footed pests also love tender, young bean seedlings. Fencing is recommended. Groundhogs can defoliate entire teepees in a few minutes.
The biggest disease problem is root rot, which you should be able to avoid with well-draining soil. If you have a particularly rainy season, be sure to turn off your automatic irrigation.
Varieties of Lima Bean
Breeders are continually working to improve yields and come up with shorter season varieties. Some are better for long, warm season climates and others excel in more temperate zones. There are many heirloom varieties still being offered and perform as well as the newer varieties.
- Christmas: These are large, burgundy and white beans have a potato-like texture. They are an heirloom variety and take 90 days to grow.
- Jackson Wonder butter bean: These buff-colored beans have burgundy speckles. They handle heat well as well as a shorter season and take about 66 days to grow.
- King of the garden: The most commonly grown variety, it has large white beans that are produced over a long season (88 days).
- Henderson’s bush: This is a very old and reliable variety with small white beans. It keeps producing for weeks and grows in about 65 days.
- Fordhook 242: A heavy producer of medium sized green beans, this variety is a good choice for cooler climates. It takes about 72 days to grow.