Cowpea- A Diverse Group of Florida Friendly Super Beans

Cowpea is a gem gifted to the world by thousands of African farmers and gardeners who selected genetics over millennia for myriad forms of this incredible crop resource. Long pre-dating the Colombian era, cowpeas made their way into India and eventually Southeast Asia where they would be selected into the form we call yard long beans. Cowpea is known by many names such as black eyed peas, southern peas or simply “peas” to many in the South. They are a tropical bean crop that thrives in heat and humidity, which is what has made them such an historically important crop in the American south and throughout the tropics. The immature beans, dry beans, pods and greens of the plant are consumed. The multi-functionality of cowpea extends even further with it being a very efficient nitrogen-fixing plant for cover cropping and animal forage. This suite of traits makes cowpea a very ideal option for Florida farms and gardens. Of all the domestic legume species I have attempted to grow (lots), cowpea stands out by far as the most well adapted to Florida growing conditions. It not only stands up to our unique and challenging growing situation, but outdoes itself.
There are many distinctive types of cowpea with unique traits that make them differently adapted to various farm and garden situations. The impetus for this article is to highlight some of the varieties of cowpea we have identified as well suited to our growing ventures and their particular applications. Being a high-protein bean, cowpea is an ideal crop as a staple food for those seeking self sufficiency from their gardens. If I had to choose a small list of crops to survive on from my Florida garden, cowpea would be near the top of the list. In Florida, various types of cowpea can be cultivated roughly through the months of March-November when temperatures are high. Cowpea is a nitrogen fixing crop, meaning it produces much of its own fertilizer and can tolerate growing in poor soils.

Climbing Cowpea

In this section I will highlight two fantastic varieties of cowpea we grow. Many types of cowpea are robust, climbing vines that grow in the field for many months. These plants can be valuable as cover crops due to the high biomass production but can be tricky to intercrop with other plants which they can rapidly swallow. Growing them on fences or trellises is an ideal way to get the most out of the crop.

Puerto Rican Black Cowpea

This variety was discovered by our friend, Taylor, who saw it growing in a Puerto Rican neighbor’s yard in Florida. He then identified that it was extremely robust and would grow in sand with minimal inputs or water and go on to produce hundreds of pods. That same experience has been the case for us. When grown on a trellis, this plant swallows the structure rapidly and produces incredible amounts of beans. The beans are long and typically contain around 15 seeds. This variety must be very resistant to nematodes, as it grows in very poor soils with no apparent issue. Most critically, this variety is totally resistant to cowpea curculio. Cowpea curculio sting the peas through the pods and ruin them. We purchased many kinds of cowpea to trial and all of them from catalogues were heavily attacked by this pest. Puerto Rican Black gets no damage from curculio and produces beautiful black dry beans. The pods are tough from a young age and are not good to eat as snap beans. The shelled fresh peas are a delicious food source. In the past this variety always waited until Fall to bloom. Weirdly, in 2022 in began blooming and producing in the summer when days were long. We don’t understand this disparity yet! This is a rugged food producer that can be, for the most part, planted and ignored. It has the wonderful trait of rot resistance in the dry pods. The pods can be rained on for several days when mature before mold starts to set in on the seeds. This variety is not offered in catalogues and is therefore not available to most gardeners in the US. We are trying to change this by offering it here.

Puerto Rican Brown Cowpea

Puerto Rican Brown is a cowpea that came from fruit explorer legend Crafton Clift. Crafton trotted the globe for decades exploring and promoting food plants. This bean popped up as a volunteer in his garden in Puerto Rico where is swallowed a whole fence and produced thousands of viable seeds. What is striking with this variety is the similarities it shares with Puerto Rican Black. Both originate on the same island but come from totally different sources. Like PR Black, it is resistant to cowpea curculio. The vines grow in the same manner and the pods look similar. The only downside of this compared to PR Black is that the beans easily mold if the mature pods are rained on. It has the advantage though of having young pods that are tender enough to be eaten as a snap bean. This variety has historically also been day-length sensitive and does not start producing blooms and pods until days shorten in the late summer or fall.

Crafton brought this bean to a conference to share with me but there was one catch. He could only find one seed to share. He brought the other seed he had squirreled away to share with another friend. She graciously gave me seed number two. I took these two seeds and sowed them inside of an elaborate cage to protect them from rabbits and faithfully watered them. From those two seeds I was able to grow back a viable population. I don’t know if Crafton ever found more seeds but those two beans may have saved this variety from disappearing entirely in the continental US! For these reasons this cowpea is more than just a great food plant to me but a sentimental piece of living history. This varietiety is available here.

Bush Cowpea

Bush varieties are by far the most prevalent type in US seed catalogues. This group includes the famous black eyes pea and purple hulled pink eye pea. They are very ideal for commercial production of field peas for fresh beans, dry beans and even u-pick operations. Some years ago I shopped around and bought what must have been two dozen varieties to trial. The results were relatively disappointing with every single variety being susceptible to cowpea curculio damage. Many of these varieties also succumb to nematodes. These vary a lot in plant form with some being very small determinate plants and others having a more sprawling habit with some degree of climbing vines. Day-neutrality seems to be a feature of all bush cowpeas. We would love to find a variety that combines drought tolerance, nematode tolerance and curculio resistance in a type of pinkeye purple hull or other bush cowpea, but for now, these types of cowpea don’t get much attention from us. Since curculio isn’t a problem on our farm (yet, fingers crossed) we will probably revisit that collection of bush cowpeas again to evaluate.

Yard Long Bean

Yard long bean is an Asian subspecies of cowpea botanically referred to as Vigna unguiculata spp. sesquipedalis. Vast diversity exists within this group. These varieties are specifically grown for the tender pods, eaten the same way as green beans. This is a perfect analog to common bean which has dry bean varieties (black bean, navy bean, etc) and green bean varieties. In the Asian tropics, long bean is a ubiquitous vegetable. It is very tolerant of tropical heat and humidity, making it a fantastic choice for Florida vegetable gardens. Unfortunately, it seems in the selection process towards tender pods, this subspecies lost much of the hardiness and pest tolerance of normal cowpea. Aphids and other pests can sometimes afflict long bean which typically leave most cowpeas alone. It is still a hardy, heat tolerant option that can be grown even in Florida summers when growing normal green beans is not possible. It can also be grown in spring and fall provided it is hot out. Typical yard long beans are vigorous vines which require a sturdy trellis. The pods come in a range of hues of green, white and red.

Guyana Long Bean

Our current go-to long bean is Guyana Long Bean, another treasure collected by our friend Crafton Clift in South America. What makes this variety unique is that the pods grow to be extremely long, sometimes exceeding 40 inches and living up to the yard long moniker. Pods of this variety need to be eaten when they are relatively thin and immature for top quality. On our farm this has been a nice productive bean variety. It makes a fun conversation piece for visitors and really opens up people’s minds to the range of fantastic plants that are out in the world. We are currently having a hard time keeping up with seed demand but we do offer this variety here.

Bush Yard Long Beans

There are lesser known forms of long beans that grow as bushes or sprawling half-runners and do not require a trellis. The pods are much shorter so it may be more appropriate to call them
“foot long beans”. It occurred to us that many gardeners may prefer to not have to deal with the trouble of building trellises for their summer garden, so we collected some of these types to work with. Our planting of varieties from China and India in the summer of 2022 has been very productive. Originally we planned to only keep one variety but 3 of them fit our needs well, so we will be offering them as a mix. Some produce as early as 55 days while other plants will begin producing a week or two after that. There is variability in how determinate they are, with some producing running growth that prolongs flowering and harvest. Our thinking is that growing these gives the longest spread out harvest of a planting. In our 4’ wide garden bed, a double row of these filled out beautifully, leaving no space for weeds to grow, but also tame enough not to sprawl into the walking path. For many home gardeners these should be a really pleasant addition to the summer raised bed plantings.

Thailand Long Beans

Thailand long is a variety from ECHO which our friend, Rick, turned us on to which he learned to appreciate in Thailand. This variety is a multi-purpose type that can be enjoyed as a fresh pod, shelled pea or dry bean. It has a semi-bush sprawling habit and is not aggressively climbing but has some twining tendencies. Rick appreciates this variety as a ground cover under young fruit trees and plants it widely. A double row planted in our raised bed was a little too vigorous for the space and sprawled out to swallow the walking paths. Our initial experiences with this cowpea are promising with it appearing resilient and extremely healthy. It does not seem to be day-length sensitive and will produce pods during the longest days of the year. Rick reports that he has never seen curculio damage to the seeds and that the drying pods have good rot resistance. This seems like a great multi-purpose variety and we are in the process of growing out a seed crop. When we have this available it will be on the website to purchase.

Cover Crop Cowpeas

Cowpea can make a fantastic green manure/cover crop. It has the advantage over some other cover crops of also producing food. Some types of cowpea can be sown in a field or garden during a summer fallow period and will rapidly outcompete most weeds. An impressive amount of biomass can be generated and significant amounts of nitrogen can be left for following crops. A classic type used this way in the South is “Iron and Clay” which can often be purchased affordably in 50 pound sacks. We used to use a mix of Iron and Clay cowpea and velvet bean (Mucuna pruriens) as a cover crop for gardens we wanted to put to sleep for the summer.

More recently, we are intrigued by cowpea as a living ground cover underneath young fruit trees that can suppress weeds and improve the soil. The problem with every variety we know of that can be purchased in a US seed catalogue is that it is either a more fickle, short-lived bush kind or a rugged climbing vine. Bush types don’t stick around very long to suppress weeds and generates biomass. The climbing vines need to be routinely pulled off of trees or they will be swamped, making it not a very ideal combination. We believe we have cracked the code for this problem with “Mavuno” cowpea!

Mavuno Cowpea

Mavuno is a cowpea we acquired through our friends at ECHO. It originally came from a missionary who collected it in Tanzania. This cowpea is ultra drought hardy and vigorous and has the unique habit of sprawling across the ground like a sweet potato. It has zero inclination to twist or twine up anything. This may not be an extremely unique trait in the world of cowpea but it is a unique trait for what is available in the US. Unfortunately, when we grew this variety some years ago at the HEART Village the seeds were extremely susceptible to cowpea curculio damage. We don’t seem to have this pest on our farm (yet?) so this may be a great bean producer for us in addition to being a cover crop under our trees. It is a day-sensitive variety that flowers as days begin to shorten in early Fall time. Of all of the cover crops we have tried, this stands head and shoulders above the rest as the best cover crop to grow under young trees. It has a unique look with very thick stems that are unlike any other cowpea we have seen. One plant ends up densely covering quite a large footprint of ground. Mavuno seeds are large and similar to “crowder” type cowpeas.

A note on day length sensitivity…

Day length sensitivity is a feature of many tropical crops. It means that if the days are long, the plant will not flower. In a northern latitude this mean that the plant may never even make a flower before it is wiped out by the first frost. Cowpea varieties are very diverse and respond differently to day length. A general rule is that aggressively vining types are often more sensitive to day length and bush types are day length neutral. Yard long beans, including vining types, all appear to be day length neutral. This may mean that incorporating different varieties in the garden would be desired to ensure early harvests and late harvests. Some pod types may be ready to harvest as early as 50-55 days after seeding while some vining types may grow for 6 months before they begin to produce. It is important to consider this trait when selecting a cowpea for a particular growing system.