Growing fava beans in your dome greenhouse is easy, rewarding and great for your soil. Fava beans are also a great early spring or fall crop as they are frost hardy.
- Family: Fabaceae
- Botanical Name: Vicia faba
- Common Name: Fava beans, broad beans, horse beans, Windsor beans
- Type: Vegetable
- Light: Full sun, part sun
- Soil pH: Acidic, neutral
- Zone: 2-10 (USDA) – Can be extended in a dome
- Size: 2-6 ft. tall
Note: A small percentage of people can have a severe allergic reaction to fava beans, this is called favism.
Growing Fava Beans
Fava beans are in the same family as peas and also fix nitrogen in the soil. However, unlike peas, they are not twining plants. They may still need a support or trellis as they can get top heavy with the bean pods.
Best Location in a Dome for Fava Beans
Fava beans like full to part sun, so plant them where they get at least 6 hours of sunlight per day. They can grow up to six feet tall which can provide shade for those companion plants that need it.
Planting Fava Beans
These beans can be planted in early spring or in the fall. Spring planting should be after the last frost, but if you have a dome, you can plant them earlier. This is true for fall planting also as the dome will offer some protection in harsher climates.
Fava beans like cool climates. The best outdoor USDA hardiness zones to grow them in are zones 3-11.
Soaking your fava bean seeds in water for an hour prior to planting will help them germinate faster. Plant the seeds about two inches deep and six inches apart. If you are planting in rows, allow 8-10 inches between rows.
Water your seeds after planting them and be sure to keep the soil moist, but not soggy. The seeds should germinate between 10-14 days.
Care and Feeding of Fava Beans
Light
Fava beans grow well in full sun to part sun. We recommend planting them where they get at least 6 hours of sunlight per day. They also need to be sheltered from high winds (another dome greenhouse benefit!) and they do not handle high temperatures well.
Soil
Fava beans tolerate many soil types, but do require good drainage. They prefer a loamy soil that is slightly acidic to neutral, which is why we always recommend testing your soil.
Water
Attentive watering is one of the keys to a successful garden. Knowing which plants need how much water can help eliminate the problem of overwatering or underwatering. Checking your soil moisture is also important.
Fava beans do well on about one inch of water each week. Remember that many plants need extra water when flowering or fruiting.
Evenly moist soil will keep your fava bean plants happy, but take care not to water so much that the soil becomes soggy.
Temperature
The best temperature for fava bean plants is between 65 and 75 degrees F. In hotter temperatures they will struggle which also makes them more susceptible to diseases. On the cool side fava bean plants will tolerate temperatures in the 40 degree F range and lower for short periods. The best season for fava is a long, cool growing season.
The best soil temperature is between 42-70 degrees, but that accommodates either fall or spring planting! The big difference is the rate of maturity. Spring plants take about 90 days to mature and fall plants take about 240 days (overwintering) to mature.
Fertilizer
Since fava bean plants fix their own nitrogen in the soil, fertilizing is not necessary. We do recommend testing your soil in early spring. If the soil is poor in nutrients, mixing some good compost into the soil will help you grow healthy plants.
Pruning
To create a bushier plant, pinch a couple of inches off the top once they start flowering. Once you’ve harvested the ripe pods, you can prune your fava plants to just a few inches tall. Providing your greenhouse dome is cool enough, your plants may regrow and offer you a second harvest.
Growing Fava Beans – Companion Plants
If you practice companion planting, fava beans have many companion options. Here are a few for you to try, but we suggest picking the plants from this list that you will also enjoy! Catnip, celery, corn, cucumber, lovage, nasturtium, petunias, potatoes, rosemary, strawberries and summer savory.
And why do these plants help each other? We’re glad you asked!
Celery, cucumbers and strawberries are plants that are mutually beneficial to fava beans.
Peas share similar growth habits with fava beans and also enhance nitrogen levels in the soil. This benefits both plants and improves the health of the garden.
Corn helps support fava plants and fava plants replenish the soil for corn.
Basil, catnip, marigolds, nasturtium, petunias, rosemary and tomatoes help repel a variety of pests from fava bean plants.
Lovage helps improve the flavor as well as the vigor of many plants.
Summer savory helps beans improve growth and flavor plus it repels bean beetles.
Plants to Avoid
There are also some plants to avoid planting near fava plants and those are beets, garlic, and onions. These are all in the allium family and will stunt the growth of your fava bean plants. Fennel is another plant to avoid with fava, but also with most plants. Fennel inhibits most plants and is best planted away from others…it likes to be alone.
Growing Fava Beans – Harvesting
Expect your fava bean plants to take between 80-100 days to harvest time and a cool season is best. You will know the pods are ready by the look and feel. Mature beans can grow between six and eight inches long. They should be shiny green and feel full, but not spongy.
It is best to use clippers when harvesting the pods to avoid damaging the plant stem.
You can also harvest and eat the immature pods when they are about 2-3 inches long. Cook them whole or wait until the pods are mature and shell them. It is a process to shell them, but can be a fun family and friends activity.
One of the reasons that shelling the beans is time consuming is that you aren’t done when you get the pod open. Inside the pod the beans have a thick, waxy shell that has to be removed. This is usually done by parboiling the beans for less than a minute and then dunking them in an ice water bath to stop them from cooking.
The next step is to let them cool a bit, then squeeze them and the beans will pop out. The delicious buttery taste of fava beans is worth the effort!
The History of Growing Fava Beans
In a paper published in 2015 researchers reported finding the oldest domesticated fava beans in what is currently known as Galilee. They were carbon dated to over 10,000 years ago. (Probably not edible now.)
Fava beans are considered an Old World legume and are believed to have originated in the Near East. Stories of fava beans appear in myths, tombs in Egypt and archaeological sites in China, Northern Africa and the Mediterranean.
Fava Beans Trivia
- Did you know that fava beans can be pureed into a creamy dip that is similar to hummus?
- Of course the most famous quote about fava beans is from the movie Silence of the Lambs. So we could name our fava bean plants Hannibal and Clarice or is that too creepy? Have you tried a nice chianti with your fava beans? Hopefully not with liver…
- In 1993 in Turlock California, Joe Fagundes was cooking fava beans. A friend asked what he was doing and he jokingly said that it was Fava Bean Day in Portugal. The next year that practical joke turned into a fundraiser for kids with cancer and went on for more than 25 years.
- Did you know beans were used in voting in ancient Greece and Rome? To vote yes, cast a white bean. To vote no, cast a black bean. Koukia refers to fava bean and is still used unofficially in reference to the votes.
- Some cultures consider fava beans a symbol for good luck as well as prosperity.
Growing Fava Beans – Health Benefits
Fava beans are rich in plant protein as well as other vitamins and minerals. One cup of cooked fava beans provides 40% of your daily value (DV) of folate, 36% of your DV of manganese, and 22% of your DV of copper. They also provide smaller amounts of your DV of phosphorus, magnesium, iron, potassium, thiamine, zinc, B vitamins, calcium and selenium.
Another benefit of growing and eating fava beans is they contain immune boosting nutrients, they may help with Parkinson’s Disease symptoms, they are very good for bone health, and possibly help with weight loss. These are just a few of the potential benefits!
Eating fava beans is also good for your heart health. Did you know that eating foods high in potassium and magnesium help decrease high blood pressure?
We hope you consider trying fava beans in your dome greenhouse. Happy gardening!
