Days to germination: 10 to 14 days
Days to harvest: 100 to 140 days
Light requirements: Full sun
Water requirements: Regularly, but not excessively
Soil: Well-drained and fertile soil
Container: Suitable for pots
The small black bean is particularly popular in Caribbean, Latin American and Mexican cuisines. It’s also sometimes called a turtle bean or a Tampico bean. These beans should not be confused with the “black bean” used in Chinese cooking, as it refers to fermented soybeans (or Douchi) in Asia.
For nutrition, the black bean is a very good source of fiber, protein, folic acid, iron and tryptophan. They are not eaten raw or fresh, only cooked once they have dried and cured (done at harvest).
Black bean plants are usually the vining type, but some varieties grow in a shorter bush form. Either way, your plants won’t usually grow taller than around 3 feet.
Starting from Seed
Like most other varieties of dry bean, the black bean doesn’t like to be transplanted so you are better off planning to sow them right out into the garden.
Your garden location should be in full sun, and you may want to add a product called inoculant to the soil when you are digging it up before planting. It’s a common additive when planting any legumes, such as beans or peas. While it’s not strictly necessary, you will see a big difference if you use it. It just helps the plant’s roots fix nitrogen better, and it is a natural product rather than an artificial fertilizer. Your local nursery or garden center should carry it in powdered form.
Soak your bean seed overnight before your planting day, which should be after your last frost date. Vining beans will need about 3 to 4 inches between them, and 6 to 8 inches of space should be left if you are planting bush varieties. Bean seeds should be buried about an inch under the soil. Bean seeds germinate very successfully, so you shouldn’t need to plant too many more seeds than you want final plants.
Vining beans will grow to several feet in height and will need support. Put a trellis or pole in place right when you are putting in the seeds so that you don’t damage the vines or roots later on. Your vines may naturally grip the supports, but you will likely have to tie up your vines to keep them upright.
Water your plants regularly, but don’t overwater. They will suffer if their roots are left wet for too long, which is why you need to choose a well-draining location to plant. Let the soil dry out a bit between waterings.
If you decide to use any fertilizer, make sure to only use mixtures with low nitrogen content. Beans make their own nitrogen, and adding extra to the soil will leave you with extremely leafy plants and no beans. You probably don’t need to add any extra nutrients at all.
Black bean roots grow shallowly under the ground, so don’t be digging too heavily around your plants as you try to take out the weeds. Either pull by hand, or layer on some organic mulch.
Black beans will grow just fine in large pots, but you will need a number of plants to get a usable harvest. Most people will grow about 8 plants per person, so it may not be that convenient to have so many plants in containers.
Bush plants do best, but you can also grow vining bean varieties in pots as well. The containers should be at least 12 inches across and deep for each plant.
Like beans grown in the garden, inoculant can be very helpful and should be mixed in with the soil when you are planting your seeds. Add an extra layer of stone to the bottom of the pot to speed up drainage so the roots don’t sit in wet soil.
Pests and Diseases
Black beans may be susceptible to bean mosaic virus, though resistant varieties are available on the market. The symptoms are a generally stunted plant, and the leaves can be curled or puckered. The disease is spread by aphids, so you should take extra care to keep them off your black bean plants.
Aphids will wash off with a garden hose pretty easily, but that’s not really a long-term solution unless you want to squirt your plants every few hours. Pyrethrin sprays can keep them off your plants for longer, but will need reapplying after any rains. Buy a box of live ladybugs and let them loose in your bean patch, and that should take care of your aphid problem.
Other insects may attack black beans, such as various kinds of bean beetles, leafhoppers and flea beetles. Remove them by hand when you see them, and spray with insecticide to help repel them further.
Harvest and Storage
Black beans are left on the vine until they have dried, so you won’t have that much difficulty figuring out when they are ready to pick. The pods will turn yellow, dry and even split open when the beans are ready. If you bite into one, your teeth shouldn’t make much of a dent in it.
If you are expecting wet weather right around maturity time, you may want to pick your pods and let them finish drying indoors. Spread out the pods where it is warm and well-ventilated until they are fully dry.
For small crops of black beans, you can shell them out of their pods by hand but that can be very time-consuming if you have a large harvest. An easier method is to dump all the dried pods in a bag or pillowcase, and either step all over the bag or swing it against a wall a few times. Then you can just sift out the debris and collect the dry beans.
As long as they are thoroughly dry, you can store them without any special conditions for up to a year. An air-tight container works best to keep out any insect pests.