Days to germination: 7 to 16 days
Days to harvest: 70 to 80 days
Light requirements: Full sun
Water requirements: Regular watering
Soil: Well-drained, can tolerate less fertile soils
Container: Most varieties, but dwarf grows best
Broad beans is another type of bean grown in the garden, different from the more popular green string bean. They are also called fava beans, pigeon beans, Windsor beans, or occasionally horse beans. Unlike the beans in the dry bean category, you can use broad beans either fresh or dried. Fresh beans are usually cooked, but they can be eaten raw as well. A very versatile bean, indeed.
Protein, calcium, fiber and small amounts of vitamins A and C are found in broad beans. They can trigger allergic reactions in some people, and can lead to a form of anemia called favism. It is not a common problem with broad beans, and tends to effect men from the Mediterranean more than any other group of people.
Starting from Seed
Unlike some other bean types, broad beans will do fine in cool soil so you can start your seeds several weeks before your last frost date. The usual timing is simply as soon as the ground thaws enough for you to dig. Seeds going out this early should be treated with a fungicide that will prevent fungus rot in the cold soil. You should be able to purchase seeds treated this way.
You can use untreated seed if you plant after your last frost date, or just sow your seeds more heavily to make up for the ones that don’t germinate. Use around twice as many seeds as you want final plants in this case.
Dig your soil, adding some compost and inoculant while you are at it. Inoculant is a black powdery substance (check your garden store) that is used when growing beans. It helps them with their nitrogen usage, and you will get a much more robust crop if you use it.
Allow for 6 inches between your plants, and the seeds can go up to 2 inches deep. The plants are generally of the bush variety but will often grow tall enough to need support, especially once loaded down with fat bean pods. Tall poles are usually unnecessary, but a couple of stakes or a round tomato-style cage would be a good idea.
Don’t wait until you have large plants to prop them up. You need to put your supports in place at seeding time so you don’t damage the roots later by sticking things in the soil. If it turns out you don’t really need the support, then just forgo the supports next season. Don’t remove them until after your beans have been harvested.
Broad beans are fairly-light feeders, meaning they don’t need many nutrients added to their soil. If you do fertilize, only use a low-nitrogen variety. The plants “make” their own nitrogen, and adding more to the soil will end up harming them.
Once the plants start to produce their bean pods, pinch out the tops so it doesn’t grow any taller. Your plants will have more nutrients and moisture to produce better beans rather than wasting resources on more leaves.
Keep your plants watered though they will withstand a dry spell or two with no problem. Don’t let too many weeds come into your bean patch, but don’t dig too deeply to remove them either or you an harm your plants.
Because of their relatively shallow root systems, broad beans will grow quite well in containers. Varieties that are bred to be smaller (dwarf plants like the Sutton) will work best though you will get a correspondingly smaller harvest with short plants. Full size ones will work just as well.
Your pots should be 10 to 12 inches across and roughly the same in depth. Dwarf varieties won’t need any support, but plan for some stakes or a cage if you use regular-sized plants.
If you are keeping your containers in a fairly sheltered spot, you may get away with starting your seeds even earlier than in the garden because the soil warms up quicker.
Pests and Diseases
Broad beans are particularly bothered by small black aphids that can harm the plant when in large numbers. Keep your plants treated with insecticide sprays, and wash off any aphids you see. They tend to cluster around the tips of the stems and on the backs of the leaves. Pinching off the growing tips (as mentioned in the Growing section) will help get rid of the aphids.
A very natural way to control your aphid populations is to introduce ladybugs into your garden. You can purchase live insects for this very reason. The ladybugs eat aphids and are excellent at protecting your garden. Organic insecticide sprays can also work with aphids.
Various bean beetles will also do damage to the leaves of your plants, though it is less of a problem than with other bean varieties. Your main concern with broad beans will be the aphids (sometimes incorrectly referred to as black flies).
Harvest and Storage
If you are going to use your broad beans fresh, then you can start to pick them once the pods fill out and the beans are a reasonable size. Smaller beans will be sweeter and more tender than the larger ones. You can also just let them dry right on the plant, and harvest them that way for dry beans ready for storage.
Once the beans start to fill out their pods, the plant will stop producing new ones. So you will typically have a single harvest when your plant reaches maturity. If you want a more staggered broad bean crop, do successive plantings through the spring months so you have mature beans at various times rather than all at once.
You can leave your beans to finish growing for a little while after the first frosts arrive as the plants can handle the cold.
Fresh broad beans can be kept in the fridge for up to a week without losing their taste or texture. They also freeze very well for a bean. Just blanch them quickly in boiling water and freeze. Long-term storage works better with the dried beans, and they will last many months if kept in a tight container.