One of the joys of growing your own food is the perennial opportunity to push the growing season and try new things, even those that aren’t typically grown here. Peanuts fit this category perfectly and, as you’ll soon learn, demonstrate that more is possible in northern gardens than conventional wisdom has taught us.
If I could toss a handful of novel seeds into every open palm across the globe, it would be this intriguing groundnut. Peanuts are in a class all their own, a beautiful plant that creates food in the most unique way, something children and adults alike will marvel at in your garden.
When the notion to grow peanuts hit, I was uncertain just how well they would do in a cold-climate garden, especially given our brief growing season. But that uncertainty fueled my desire to find out firsthand. This leguminous experiment secured space in our rambling vegetable patch simply for the adventure alone. I had seen peanuts successfully grown in home gardens in USDA Zone 6B, so I stubbornly decided it was feasible here, too.
A Fascinating Legume
Peanuts (Arachis hypogaea) are a compact plant in the legume family, native to South America. Grown globally as an agricultural crop as well as in home gardens, peanuts thrive in warm, humid subtropical regions with extended periods of heat. Peanuts grow well in the well-drained soils of the humid southern states. So, of course, I took this to mean our brief heat waves in August would produce at least a few nuts to show for my efforts.
The peanut is a fascinating plant to grow from seed, from its pinnately compound foliage to its understated flowers that quietly blossom underfoot, going completely unnoticed by the busy gardener. I speak from experience, having missed the first flush of blooms on my plants. I wised up before the show was over, and learned to slow down and appreciate this unassuming plant and its cheery inflorescence.
While sharing the nitrogen-fixing benefits of other legumes, such as peas and beans, the peanut develops its edible nut underground, more like a root vegetable than a pea. Witnessing firsthand how a groundnut is produced is all the reason you need to add these to your garden—especially if children are in the household.
Peanut flowers are a beautiful orange-yellow, resembling pea flowers. When you see a flower on a vegetable plant, it usually matures into the fruit you consume. In contrast, peanuts develop their fruit a good bit farther down from where the flower is pollinated. The fertilized flower drops a peg, which, thanks to gravity, descends down into the ground where the tip of it—this entire peg part of the fertilized ovary—swells and grows the delicious nuts we know and love. No other food I can think of grows this way. This process takes a long time—110 or more days for most varieties—and that’s why these are not a common crop in the North.
Bring on the Heat
The first year I planted peanuts, I set my expectations very low—harvesting even a small handful of peanuts counted as success in my book—because so much was left to the weather. Knowing a hot summer was necessary for success, I prepared the peanut bed with PVC hoops in the event nature didn’t grace us with a hot summer and I needed to create a sultry microclimate. During my first year growing peanuts, the heat arrived abruptly by Memorial Day, with hot temperatures maintained all summer long. The peanuts grew just fine without intervention, though for reliable harvests a light row cover would make for a strong insurance policy.
The fastest-maturing peanuts I have grown are Tennessee Red Valencia and Schronce’s Deep Black, both 110-day varieties available from several online seed companies. (See resource list.)
While brussels sprouts share these long days to maturity, they thrive on a few early frosts. Peanuts, on the other hand, stop growing once the night temperatures drop into the 40s F, which dependably occurs in September here. So June, July and August are the key to growing peanuts in the North. To work around our short growing season, sow the peanuts indoors under lights four to five weeks before transplanting.
In late April, I sow two seeds per 3-inch pot. Despite near 100 percent germination rates, I don’t typically thin them, and they do fine in this size pot for the four weeks leading up to transplanting. Since warm soil and air temperatures are my guide, I wait to transplant peanut seedlings into the garden until the weather is reliably warmer, which can be anytime from around Memorial Day to sometime in early June. I plant our peanut seedlings around 9 inches apart in rows 24 inches apart.
Peanuts need soil that is well drained and well amended. We top-dress all our beds annually with a few inches of compost and mix in slow-release organic fertilizer at transplant time. One final application of organic fertilizer is added to the plants when they begin to flower.
Like potatoes, peanuts benefit from hilling to promote the development of more nuts. I dig trenches for the transplants, and as they establish, we gently hill them up. Because peanuts are slow to establish, control weeds to help them have the strongest start possible. I have grown them both as short rows and long rows, and both worked well for us.
While we weren’t overwhelmed with pounds of fresh peanuts, the peanuts we did harvest were the most flavorful we’ve ever tasted. And if my teenager could plan the garden, it would be nothing more than rows of tomatoes, potatoes, corn and, now, peanuts, too. The large bowl of peanuts and their extraordinary flavor was more than enough for us to allot space annually.
Peanuts are a beautiful, compact plant to add to your vegetable garden. If you have children or grandchildren around, I guarantee this will be a joyful way to engage them in the garden.
This article by Meg Cowden first appeared in the March/April 2020 edition of the Northern Gardener. She is a self-taught gardener, writer and photographer. Her book on extending the garden season will be released in March 2022. Follow her on Instagram at @seedtofork.