Days to germination: 10 to 14 days
Days to harvest: 100 to 140 days
Light requirements: Full sun
Water requirements: Regularly but not heavily
Soil: Soil needs to be loose and well-draining
Container: Suitable, but not ideal
These large red beans are popular in chili, particularly in the American south. They are in the same family of beans as black beans, pinto beans and navy beans.
Like most other dry beans, kidney beans are only eaten cooked. In fact, raw kidney beans (and their sprouts) are actually poisonous. It only takes a few minutes of cooking at high heat to neutralize the toxins, which is much less than any standard cooking time for these beans.
Kidney beans are excellent sources of protein, which makes them popular as a meat-substitute for vegetarians. They also have high levels of iron, calcium and magnesium.
Starting from Seed
Unfortunately, kidney beans don’t transplant well so it’s best to just plant your seeds into the garden when the time is right rather than try to start early with indoor seedlings.
Choose a spot in the garden that will get full sun, and where the soil is loose enough to allow for good drainage. If you find the water pools up when it rains, it won’t be a good spot for your kidney bean plants. When you are digging the soil before planting, mix in a powdered product called an inoculant. It’s a natural bacterium that helps beans and peas get their nitrogen out of the soil.
Put your seeds out after your last frost date, and cover any sprouted seedlings if you do get an unexpected frost.
Space your seeds by about 4 inches if you have a vining variety of bean, and a bit farther to 8 inches if you are growing a more compact bush type. Bean seeds should be about an inch to an inch and a half under the soil when you plant.
Kidney bean plants hate to have “wet feet”, so don’t water too often unless the weather has been really dry. You should only water your plants if the soil has dried out, rather than water to keep it constantly moist.
Because kidney beans can produce their own nitrogen in their roots, they don’t really need any extra nutrients of fertilizer. If you are feeding your plants, don’t use any high-nitrogen mixtures around the beans or you will effect their growth. They may seem to thrive with more leaves, but at harvest time you’ll end up with a lot of empty pods.
Shallow roots make it difficult to hoe around a bean plant without harming the plant. You should pull weeds by hand, or use a good layer of mulch to keep out the weeds.
Kidney beans grow fine in pots, and usually do better if you are growing bush-type beans such as the Montcalm variety. They don’t vine as much and do well in smaller spaces. A 12-inch pot is suitable for a single plant, and you will need to add some support if you are growing a vining bean.
You do need several plants in order to get enough beans for anything other than occasional usage, which may make container gardening impractical for kidney beans. On average, it will take 6 to 10 plants to supply enough beans for one person’s regular use.
Add extra gravel or stones to your pot to help the water drain away, and only water your potted beans when the soil is actually dry.
Pests and Diseases
Kidney beans have nice large leaves that often fall prey to any number of beetles and grubs in the garden. Various species of bean beetle are the biggest threat, though slugs, cutworms and leafhoppers can all be found in your bean patch. If you check your plants daily, and pick off any pests you find, you may not need to spray at all.
You will also need to keep off the aphids, which are a bit harder to see than the larger beetles. Thy usually don’t do much harm on their own but they can spread bean mosaic virus, which will kill any plants that are not resistant (many varieties are).
Aside from the bugs, your bean plants can also get rust or mildew on the leaves. Bean rust is a fungus that shows up as rusty reddish-brown patches on the leaves and can be treated with fungicide, provided you start to treat the plants before it spreads through all the leaves.
Powdery mildew is less of a danger, but can kill your plants if you don’t keep it in check. It just looks like a fine white powder on the leaves that doesn’t wipe off. Again, treat with fungicide and keep your plants from being too moist. Humid air helps mildew thrive, so only water your plants at the soil level, not over the leaves.
Harvest and Storage
Kidney beans are not picked though the season, but only collected after they have completely matured and dried out. The pods will be dry to the touch, and the beans themselves will be as hard as stone. High humidity can make it hard to dry the beans out on the vine, so you may have to collect the pods to let them finish drying and curing indoors. lay them out in a warm location where there is plenty of air ventilation.
The traditional way to see if your beans are “done”, is to bite down on one. They shouldn’t be marked or dented by your teeth. Once dry, you just shell them out of their pods and either cook them or store them for later.
If you just have a few plants, you can easily break the pods apart by hand to get the beans out. For larger harvests, gather all the pods together in a pillow case or even on the floor between two sheets. Step all over them, and sift out the beans from the pieces of broken seed pods.
As long as you can keep any insects or rodents out of your dried beans, they will last up to a year if kept in a dark place.