Phaseolus polystachios
Origin: Michigan
Improvement status: Breeding population
Seeds per packet: 5
BOTANICAL SAMPLE - NOT GERMINATION TESTED
Life cycle: Perennial
We're thrilled to be offering these perennial thicket beans thanks to our friend Ken Asmus of Oikos Tree Crops in southwestern Michigan. Ken tried to retire a few years ago, but the plants apparently kept calling him back! He's still selling seeds and plants, but now he's only selling bulk amounts of seeds, pricing out the smaller customers who just want to try a packet-sized amount. So we're happy he's willing to have us buy a few things from him in bulk so we can offer them at a smaller size to all of you!
Here's what Ken has to say about his strain of perennial thicket bean:
"Related to the lima bean, our native thicket bean seeds are easy to cultivate yet hard to find in the seed trade. This is partly because of the exploding nature of the seed pods during harvest, as well as a general lack of interest in the gardening community. I grew a population of thicket beans in southwestern Michigan over the course of two decades. Each year I learned a little bit more about this unique bean including its growing habits, harvesting and culinary uses. In 2017, I harvested 2 ounces of dry seeds from my plantings. In 2018, I harvested 1 lb and 10 ounces. In 2020, I hit a record of 4 lbs! It turns out that, once established, the thicket bean produces copious amounts of beans. I also discovered that thicket bean will fruit in their first year from seed. So it is quite a precocious little bean with a massive root and durable nature. Since retirement in 2021, I no longer maintain my trellis systems for all thicket beans and now I'm involved mainly with their hybrids and other wonderful vine-type beans too. But I still keep an isolated non-hybrid version of the species in my planting, and that is what these seeds are from. They are the longest-lived of the selections I have and produce loads of small lentil-sized delicious beans.
This strain is an earlier form and fully ripens in southwestern Michigan, making it one of the most northern forms under cultivation. For my location, that means the pods turn brown starting at the end of September and continue for up to a month prior to harvest in mid-to-late October. I lay them out on screens and let them pop open on their own, covering the seeds to prevent ejection of the seeds all over the barn.
Pollination seems to improve over time as other species of native bees take an interest in the flowers, as well as other nearby annual beans I grow. Cabbage butterflies, honey bees, as well as several species of bumblebees really fill the air when these start to flower in July and August. As the roots mature, the yields increase dramatically. The older roots break down and hollow out after 10-15 years. It could be possible the roots under more strict cultivation could last consistently longer than a decade. Avoid mulch and grassy areas with brush. Voles will consume the roots.
There are some variations found within the populations but in general they are very similar. Some are more black and slightly larger. Other growers report very good yields on young plants and are trying to make selections based on yields. The seeds we're selling are from my oldest plants with best vigor and yield.
You cannot store these roots above ground in pots. Never try that. They need to be in ground during the winter. They do not tolerate the conditions of pot culture during winter.
GERMINATION: Wild beans have a hard seed coat. If you plant them as they are, roughly 1/2 to 2/3 will germinate the first year. To increase the germination rate, soften the seed coat by using a fine grit sandpaper and gently rub it on the seed. This will scar the seed and remove some of the shine. This will then make them imbibe water easily and then sprout. You can then plant directly outside under 1/2 inch of soil. The seeds throw a taproot first and then the top will come up slowly over the course of a month. Or you can soak your seed or put in a damp paper towel until sprouting begins, and then plant. Roots can go to 18 inches deep in one year and form a carrot type taproot. Otherwise, they pretty much grow like any other bean.
Diseases of thicket bean include leaf rust which will defoliate and weaken the plant. Keep in check with biological [organic approved!] insecticide Serenade which prevents its spread. Neem oil has also worked very well in the prevention of the disease for me along with rosemary extract formulas available from ARBICO."
