Growing Fava Beans: Winter Cover Crop and Food
Fava beans occupy a unique position in Santa Cruz gardens. They grow through our mild, rainy winters when most other vegetables are dormant, produce edible beans in spring, and improve your soil in the process. Whether you grow them for food, as a cover crop, or both, favas reward minimal effort with substantial benefits.
This guide covers everything you need to know about growing fava beans in Santa Cruz County. You will learn when to plant, how to care for them through winter, and how to harvest for fresh eating or soil improvement.
Even if you are not sure you like eating fava beans (their distinctive flavor is an acquired taste), they are worth growing for soil benefits alone. The nitrogen they fix and organic matter they add makes following crops noticeably more vigorous.
What Makes Fava Beans Special
Fava beans (Vicia faba), also called broad beans, differ from common beans in several important ways.
Cool-Season Growth: Unlike heat-loving common beans, favas thrive in cool weather and tolerate frost down to about 15 degrees F. They grow actively through Santa Cruz winters when other crops are dormant.
Nitrogen Fixation: Like all legumes, favas partner with soil bacteria to convert atmospheric nitrogen into plant-available form. UC Master Gardeners note that fava beans are among the most effective nitrogen-fixing cover crops for home gardens, contributing significant amounts of nitrogen for following crops.
Deep Taproots: Fava roots penetrate 3 to 4 feet deep, breaking up compacted soil and accessing nutrients unavailable to shallow-rooted crops. This root structure also makes established plants surprisingly drought tolerant.
Dual Purpose: Favas provide both food and soil improvement. You can harvest beans for eating, then turn under the remaining plants. Or grow them purely as a cover crop if you prefer not to eat them.
When to Plant Fava Beans
The ideal planting window runs from October through early January, with earlier plantings generally producing better yields.
October to November (Optimal)
Plants establish strong root systems before the shortest days of winter. Early plantings produce the largest plants and heaviest yields come spring. Beans are typically ready to harvest in April or May.
December to Early January (Acceptable)
Later plantings still produce but with smaller plants and lighter yields. Growth slows during the shortest, coldest days but resumes as days lengthen in late winter.
Why Not Spring?
Fava beans planted in spring face several challenges in Santa Cruz. Rising temperatures trigger flowering before plants develop fully, resulting in poor yields. Spring plantings also miss the opportunity to improve soil over winter when beds might otherwise sit empty.
Planting Fava Beans
Fava Bean Growth Stages
From Seed to Harvest
Santa Cruz timing: Plant October through February for spring harvest. Fall-planted favas overwinter as small plants and take off in late winter when days lengthen. Total time: 80-100 days.
Site Selection
Favas tolerate partial shade better than most vegetables, making them useful for spots that get limited winter sun. However, full sun produces the sturdiest plants with the heaviest yields.
Choose a spot with reasonable drainage. While favas handle winter rain well, standing water promotes root rot. Raised beds work excellently for favas in heavy clay soils.
Soil Preparation
Favas are not fussy about soil fertility since they fix their own nitrogen. Simply loosen soil and work in some compost for structure. Avoid high-nitrogen amendments, which actually reduce nitrogen fixation.
If your soil has not grown legumes recently, consider inoculating seeds with rhizobia bacteria specific to favas and vetch (different from bean and pea inoculant). This ensures optimal nitrogen fixation.
Spacing and Depth
Plant seeds 1 to 2 inches deep and 4 to 6 inches apart in rows 18 to 24 inches apart. You can also plant in blocks with 6 inches between plants in all directions.
For intensive beds, double rows 6 inches apart with 2 feet between double rows works well and provides mutual support as plants grow tall.
Germination
Fava seeds germinate readily in cool, moist fall soil. Expect emergence in 7 to 14 days depending on soil temperature. Unlike common beans, favas do not mind cool, wet conditions during germination.
Soaking seeds overnight before planting speeds germination slightly but is not necessary. Some gardeners nick the hard seed coat with a file or sandpaper to speed water absorption.
Care Through Winter
Established fava beans need minimal care through our mild winters.
Watering
In a normal rainy winter, favas need no supplemental irrigation. Their deep roots access moisture from well below the soil surface, and winter rains provide plenty of water.
If winter rains are sparse (December and January with little precipitation), water deeply every 2 to 3 weeks. Check soil moisture by digging down several inches. If it feels dry 4 inches below the surface, water.
Supporting Tall Plants
Fava plants can reach 4 to 5 feet tall by spring, especially vigorous early-planted stands. Heavy rain or wind can knock plants over, especially when loaded with developing pods.
Provide support before plants get too tall to handle easily. Options include stakes and string around the outside of the planting, tomato cages placed early, or simply growing in dense blocks where plants support each other.
Pest and Disease Issues
Favas have few serious pest problems in our area.
Aphids sometimes colonize growing tips in spring as weather warms. Black bean aphid (Aphis fabae) particularly favors favas. Control with strong water spray or insecticidal soap if populations are heavy. Removing severely infested shoot tips can reduce populations without chemicals.
Chocolate spot (Botrytis fabae) causes brown spots on leaves in wet conditions. Improve air circulation, avoid overhead watering, and remove affected leaves. The disease rarely causes serious damage in home gardens.
Rust occasionally appears as orange-brown pustules on leaves. Remove affected leaves and ensure good air circulation. Rarely serious in our climate.
Harvesting Fava Beans
The timing of your harvest depends on how you want to use the beans.
Three Ways to Harvest Favas
Choose Based on How You Want to Use Them
Tender Tips
Bonus HarvestPinch off the top 4-6 inches of growing tips when plants are flowering. A delicious bonus crop most gardeners miss.
Fresh Beans
Most PopularPick when pods are bright green and plump. Beans inside are tender with a creamy texture. Requires double-shelling.
Dry Beans
Long StorageLeave pods on plant until completely black and dry. Beans rattle inside. Store for months like any dry bean.
Double-Shelling Fresh Favas
Young Pods (Whole)
When pods are about 3 inches long and beans inside are barely visible, you can eat the entire pod like a snap bean. At this stage, pods are tender without the tough fibrous strings of mature pods. This is a delicacy that few people experience since it requires a well-established planting to sacrifice young pods.
Fresh Shelling Beans
The most common harvest stage. Pick pods when fully filled out and beans inside are thumbnail-sized or slightly larger. Pods should be plump and green, not yet turning black or papery.
Shell the beans and use immediately or freeze. Fresh favas have a brief window of peak quality, and the distinctive flavor is best within hours of harvest.
To prepare fresh favas: Bring a pot of water to boil. Add shelled beans and blanch for 1 to 2 minutes. Drain and plunge into ice water. Slip off the pale outer skin by pinching one end of each bean. The bright green inner bean has the best texture and mildest flavor.
Small, young beans can be eaten without removing the skin. Larger beans develop a tougher, slightly bitter skin that most cooks remove.
Dry Beans
For dry storage, leave pods on plants until they turn black and papery. Seeds should rattle inside and feel hard when pressed. In Santa Cruz's humid spring conditions, you may need to pull entire plants and hang them in a covered spot to finish drying.
Completely dry beans store for years in airtight containers. Rehydrate overnight before cooking.
Using Favas as a Cover Crop
Even if you never eat a single fava bean, growing them as a cover crop provides substantial soil benefits.
Favas as Cover Crop
Food + Soil Improvement in One Plant
Cover Crop Timeline for Santa Cruz
Cut plants at soil level rather than pulling them up. Leave roots in place to decompose and release their stored nitrogen for your next crop.
Maximum Nitrogen Benefit
For the most nitrogen contribution to following crops, cut plants down when they begin flowering or shortly after. At this stage, plant tissue is high in nitrogen and decomposes relatively quickly.
Cut plants at soil level, leaving roots in place. Chop the tops coarsely and either leave them on the soil surface as mulch or turn them shallowly into the top few inches of soil.
Wait 2 to 3 weeks after incorporating fresh plant material before planting your next crop. During this time, soil microbes are actively breaking down the green material and may temporarily tie up nitrogen. After decomposition progresses, nitrogen becomes available to following plants.
Balancing Food and Soil Improvement
You can harvest beans for eating and still get significant soil benefits. The roots (where much of the nitrogen is stored in nodules) remain even after you harvest pods. Cut plants at soil level after the final harvest and leave roots to decompose.
The above-ground plant material, even after pod harvest, contains nitrogen and organic matter. Chop it and turn it under or leave it as mulch.
Following Crops
Favas make excellent predecessors for nitrogen-hungry summer crops. UC Master Gardeners recommend following fava beans with corn, squash, tomatoes, or other heavy feeders to take advantage of the nitrogen left behind.
A classic rotation in Santa Cruz gardens: fava beans (fall to spring), followed by tomatoes or squash (summer), followed by leafy greens or root vegetables (fall to winter), then back to favas.
Varieties for Santa Cruz
Several fava varieties grow well in our climate.
'Windsor' (75-85 days from spring emergence to harvest): The standard variety, widely available and reliable. Large beans with classic fava flavor. Tall plants (4 to 5 feet) need support.
'Aquadulce' (85-90 days): Spanish variety bred for fall planting and overwintering. Particularly cold-hardy with good disease resistance. Long pods with 5 to 7 beans each.
'Sweet Lorane' (small-seeded, 75 days): Smaller beans bred specifically for cover crop use, though they are edible. Very cold-hardy and vigorous. Good choice if soil improvement is your primary goal.
'Broad Windsor Long Pod' (80-90 days): English heirloom with extra-long pods. Large beans with excellent flavor. Needs good support.
Find fava bean seeds at San Lorenzo Garden Center, Mountain Feed & Farm Supply in Ben Lomond, or order from Johnny's Selected Seeds or Territorial Seed Company.
Growing Favas by Microclimate
Coastal Fog Belt
Excellent conditions for favas. Mild winters mean steady growth with minimal frost damage. Humid conditions may increase chocolate spot disease, so ensure good air circulation.
San Lorenzo Valley
Good growing conditions in most areas. Higher elevations see colder winters, and heavy frost can damage top growth, but plants usually recover. Provide extra support in exposed, windy locations.
Under Redwoods
Favas tolerate partial shade better than most vegetables, making them one of the best options for shaded winter gardens. Expect somewhat smaller plants and lighter yields than in full sun, but they still provide valuable soil improvement and some harvest.
Inland and Pajaro Valley
Excellent conditions. Warmer fall weather gets plants growing quickly before winter. Spring harvest comes earlier than in cooler coastal areas.
Frequently Asked Questions
Do I have to remove the skin from fava beans?
Young, small beans (thumbnail size or smaller) can be eaten with skins on. Larger beans develop a tougher, slightly bitter skin that most people prefer to remove. Blanch beans briefly, shock in ice water, then slip off skins by pinching.
Why do my fava plants fall over?
Fava plants can reach 4 to 5 feet tall and become top-heavy when loaded with pods. Wind or heavy rain knocks them over. Provide support with stakes and string, grow in dense blocks for mutual support, or plant earlier to establish stronger stems before pods develop.
Can I plant favas in spring instead of fall?
Spring planting is possible but not recommended in Santa Cruz. Rising temperatures trigger early flowering before plants develop fully, resulting in disappointing yields. Fall-planted favas take advantage of our mild winters and produce much better.
Are fava beans and broad beans the same thing?
Yes, they are the same plant. "Fava" comes from Italian, "broad bean" from British English. You may also see them called horse beans, field beans, or tick beans in older sources.
My fava plants have black insects clustered on the growing tips. What should I do?
Black bean aphids (Aphis fabae) commonly colonize fava growing tips in spring. For light infestations, spray with a strong jet of water. For heavy infestations, use insecticidal soap or remove and dispose of the most affected shoot tips. Ladybugs and other beneficial insects often control aphid populations naturally.
Can I save fava seeds for next year?
Yes, favas are excellent for seed saving. Let pods dry completely on the plant (until they turn black and papery), harvest, and store dry seeds in a cool, dry location. Properly stored seeds remain viable for 3 to 4 years.
Do I need to inoculate fava bean seeds?
Inoculation improves nitrogen fixation, especially in soil that has not grown favas or vetch recently. Use inoculant specific to favas and vetch (different from bean and pea inoculant). If you have grown favas before in the same spot, the bacteria are likely already present.
Free Resources
Download these helpful guides from Your Garden Toolkit:
Seasonal Planting Calendar: Includes fava bean planting times for fall and winter.
Companion Planting Guide: Learn which crops benefit from following fava beans.
Fava Beans: Food + Cover Crop
Two ways to use your fava bean crop
