Growing Potatoes Organically in the Northeast U.S.A.
The Gift of the Incans
Solanum Tuberosum: The Potato
The humble Potato, while lacking in glamour, has a matchless virtue: There is no other food plant that you can grow that will provide so great a poundage of excellent food in so small a space as potatoes. Not corn, not wheat, not any other food plant. It is also not a greedy plant, as far as needing fertilizers, which if purchased, are expensive. A normal garden soil will produce a fine yield.
How Much do I Need?
The best method is to weigh out how many pounds you and yours eat at a sitting, then multiply that by how many meals a week you’d like to get, then that number by 52 for a yearly total.
For instance, say you and yours eat 2 pounds of spuds at a meal. Let's assume you want to have them 4 times a week. Multiply 2 times 4 times 52 for a total of 416 pounds (roughly 7 bushels). You can expect to harvest a bushel (60 pounds) of potatoes from a single 30-foot row of all but the fingerling types, (those usually yield about half as much). Therefore seven 30-foot rows will suffice to provide you with all you want.
What are the Different Types?
White fleshed and brown-skinned potatoes have a bewildering variety of names but are pretty much the same. Russet-type potatoes are specifically for baking and Fast-Food style French Fries, and are drier and mealier in texture.
Red-Skinned, white-fleshed potatoes are similar in taste and cooking as the brown skinned white fleshed types.
Fingerlings are usually creamy fleshed and brown-skinned and fusi-form shaped (Like a skinny football). The yield is lower than the larger potatoes but the flavor is gourmet quality.
Purple potatoes are relatively new, but taste and cook like the white-fleshed types.
Yellow-fleshed potatoes run the gamut from the bright yellow like Yukon Gold and German Butterball to the creamy Yellow of Carola. They have a more distinctive flavor, more like Fingerlings than the white-fleshed kinds. Yukon Gold stands alone as being of a more mealy texture (like Russet) and sweeter in taste.
When do I Plant Them?
In our area planting the potatoes at the beginning of May is a good target. That will provide you with some new potatoes for the 4th of July, and the main crop will be ready by mid-August.
Potatoes can stand a light frost, and even a heavier one will be survived with only some leaf damage.
In case of frost when the plants are just emerging, you can pull soil over them if you're concerned.
How to Plant
Cut tubers larger than a hen's egg in half or quarters. Make sure each piece has at least one good sprout starting. Let the cut pieces dry out a day or two before planting them to avoid them rotting. Take care to not break off the sprouts that form as much as possible.
An old Vermont Folk practice is called “Chitting”. The potato pieces to be planted are spread out on burlap and exposed to indirect sunlight for a week or more until short, thick, very green sprouts develop. Then they are planted. The advantage is that the sprouts are not spindly and so less liable to break off, and the plants have used the sunlight to begin the growing process earlier than otherwise.
Potatoes are very susceptible to diseases so grow them where no Potatoes, Tomatoes, or Peppers have been grown for at least 2 years. I have found the very best, biggest, healthiest plants and harvests come from plants grown in what was sod the year before.
Mark a straight line on the soil with a stick down the garden where you want your row of potatoes.
Then, using a hoe, shovel, or rototiller attachment, dig a trench roughly 8 inches deep. Leave the soil heaped up alongside of the row.
Mark a straight line on the soil with a stick down the garden where you want your row of the soil heaped up on either side of the trench.
Place the potato pieces on the bottom of the trench, sprouts pointing to the sky.
Now cover the seed potatoes lightly with some of the soil from the sides of the trench.
Do not be tempted to crowd the plants thinking you will get more potatoes from having more plants in the row. The more you crowd them the less each plant will produce and they will be smaller tubers as well. Plant them a foot and a half apart for fingerlings and 2 feet to 2 and ½ feet apart for the larger varieties.
Planting in Straw Mulch
This is an alternative way of growing spuds. You'll need to have access to bales of straw. The method is straight forward and simple.
Loosen the dirt of the row. Lay the seed potato on top of the soil. Cover with 8 inches or so of straw. As the plant grows through the straw keep adding more straw, tucking it up around the plant. It must be thick enough to exclude light.
When it is time to harvest, pull aside the straw and pick up your spuds.
You can use pine needles in the place of the straw too.
Sounds simple, right? Then why doesn't everyone do it that way?
Well, there are downsides as they say.
First, growth is slower to begin as the soil is shaded and hence cooler. The yield is usually a bit smaller too. One can easily live with that though.
What really can be a problem is pests.
Slugs absolutely thrive in the moist, dark environment provided by the deep mulch. However, the real problem is that Voles (Meadow Mice) will probably find your patch. Maybe not the first year, maybe not the second, but in my experience they will sooner or later.
When they discovered mine they devoured everything and there was no clue until harvest time. Since then I don't use straw mulch. (They also ate all my lettuce and peas too.)
Perennial weeds are not stopped by that mulch either. Bindweed, Witch Grass, Milkweed and others can run rampant.
That being said: Try it yourself.
Cultivation: Caring for the Plants
Once a week go through and hill the plants up. (That means to pull the soil from both sides of the row up and around the plant carefully with a hoe. This is to keep the developing potatoes from being exposed to the sun which will turn them green which is poisonous to humans.)
Potatoes are mostly water, so they need a good watering once a week if no rains occur. Daily watering isn't necessary. Better one good soaking once a week than a brief watering daily.
Once the plants begin to brown and die back in August, simply keep an eye on them to ensure as few potatoes as possible are getting exposed to the sunlight before they are dug for winter storage.
Pests You'll Have to Deal With
Cutworms : Are the caterpillars of several moth species. They hide mostly during the day just under the soil near the plants, and at night chew through plant stems, dropping them like lumberjacks. They first begin to be a problem as soon as the plants emerge from the soil, but are usually done by the 4th of July.
When you see a drooping, wilted, or completely severed stem of a Potato plant, carefully dig around the base of the plant in the top 2 inches of soil. The cutworm will appear coiled up into a circle. Dispose of as you see fit; toss them to your chickens, squish them, whatever. Toads, Robins, Cardinals, and Frogs will eat them whenever they can too.
Slugs: Relatives of snails, these Gastropods have no shell and are slimy, which is a great defense against a lot of predators. Toads are the only animals I know of that will willingly eat them. In damp years they can be a real problem, eating young leaves whole. They also will munch tunnels through full size tubers too. Handpick them and squash, or you can sprinkle them with salt (though it is really sadistic).
Voles Microtus pennslyvanicus: AKA as Meadow Mice, these rodents can eat the tubers at or near the surface, and as mentioned before, if you use mulch they can completely devour your crop.
Tortoise Shell Beetles Eurypepla jamaicensis: The beetle itself is rather unremarkable, being flat, dully colored and about the size of a small, flat pea. Its larvae however possess an effective trait in repelling predators: They carry all their excrement on their back. Yes, you read correctly. Luckily, they do not cause a great deal of damage usually.
Around here, these Beetles and the Old Fashioned Potato Beetle (below) arrive at the beginning of June.
Old Fashioned Potato Beetles: Lema trilineata: At one time this was THE potato bug. Now, it pales in comparison to the Colorado Potato Beetle in damage done. Like the Colorado, it is the larvae, that hatches from eggs laid on the underside of the leaves, that does all the damage. Handpick the larvae. If you can catch the adults great, but they are fast and wary. If even your shadow falls on them they are airborne. In the cool of the morning they are easier to catch than later in the day. But the easiest, if cruelest time to catch them is when they are mating.
Colorado Potato Beetle: Leptinotarsa decemlineata: This is the bête noir of potato growers.
Originally described by Lewis and Clark as a pest on the Horse Nettle out west, once potato farming found the cozy environs of Idaho and other excellent potato farming areas, it took to its new food source with a vengeance and spread like wildfire.
A rather handsome beetle with its dark yellow-orange carapace and black stripes, its larvae can strip a patch before you know it.
It appears almost like Clockwork here around June 10th.
In the mornings it is hard to find, staying hidden in the leaves. In the heat of the afternoon however, they come to the very tops of the plants and are easily spotted. Not as fast as the Old-Fashioned Potato Bug, they still have some tricks up their sleeves. If you grab for them and miss, they tuck and roll; dropping quickly to the ground where they instantly can disappear.
Once again, as awful as it is to delicate sensibilities, the best time to snatch them is when they are mating.
It has, however, several traits that can be used to control it without resort to chemicals. It lives in mortal dread of birds. Specifically, those species that inhabit the interface of woods and fields; such as the Bluebird and the Cardinal. An old folk name for the Cardinal is in fact the “Potato Bug Bird”.
By placing your potato patch, (at least one side of it) near a hedge row of trees and brush you give the birds easier access to the bugs. The Beetle recognizes the threat and tends to stay at least 20 feet from the trees.
Its native habitat is open, low grass land. It instinctively distrusts and avoids trees and other tall features that block its flight, which is low, under 6 foot off the ground in my experience. If trees are not available, a tall (6 foot or higher) fence of wire mesh will work almost as well. So will growing a row of pole beans along the edges of the potato crop (choose the side of the prevailing winds in your area if you’re only going to plant one side of the patch).
B.T. (Bacillus thuringiensis) once made organic control easy. Composed of a naturally occurring bacteria first isolated in Thuringia, Germany, it caused terminal illness in the larvae that ate it when it was sprayed in solution on the leaves.
It is still available under the names Dipel and Thuricide.
Harmless to humans unless ingested, when it causes gastrointestinal distress, it was considered safe and effective.
However, when corn growers began planting untold acres of B.T. corn, a genetically altered corn that produces the toxin in EVERY CELL of the plant, it began to lose its effectiveness: Over-use. (They never learn.) And, now it has been implicated in “Hive Collapse”, the plague of destruction visiting honeybee colonies.
So, in good conscience I do not advocate using it anymore. And for backyard growers there really is no need to. A pleasant daily stroll through your patch on the look-out for pests is sufficient.
All 3 of the Beetles mentioned above lay their eggs on the underside of Potato leaves. While patrolling your potato patch, gently turn over the leaves to look for them.
There is no need to be an Entomologist to recognize them as trouble. Any orange-ish egg clusters should be destroyed.
If you see a bright yellow cluster of eggs; leave them alone. They are Ladybug Beetle eggs (One of the 'good bugs').
The first chance to harvest comes just after the plants' flowers begin to fall. These are the much coveted “New Potatoes”; small, virtually skinless, and melt-in-your-mouth tender.
The old term is “Scrabbling” new potatoes. It simply means stealing your hand under the plant and feeling for potatoes and taking a few from each plant, leaving the plant to continue to grow.
(Personally: I’m too impatient, and we plant a lot of potatoes. So, when I feel the tubers are likely there, I pull up a plant and see. If they are ready I pull as many plants as needed to make a meal.)
The main harvest comes after the plants have turned brown and withered away. I wait until after a few frosts to ensure against picking up any Late Blight live spores. So far it has worked every time.
Dig your potatoes. Okay: This is work. For a few plants, a trowel will work. For more; use either a potato hook or shovel. I prefer the hook, but it does require more arm strength than a shovel, which is my wife’s choice.
The hook damages much less of the tubers though. After a little while you will gain a feel for it. I sink the hook into the soil ahead of the plant and then pull it though the soil toward me. You will feel it hit potatoes, which will pop up to the surface.
With a shovel; sink the shovel down into the ground to the outside of the hill and turn it over. If You see potatoes, pull them out. Keep digging carefully until you think you’ve got them.
Regardless of which way you choose, the thing to remember is that the potatoes grew directly under where the plant spread its foliage.
As you harvest, place the tubers from each plant together on top of the soil where you’ve already dug. It’s a good idea to let them dry in the air for an hour or so. The skin hardens then, protecting them more. And the dirt falls off easier.
Afterwards, store them in either boxes, sacks, or bushel baskets; whatever you have. Personally, we use old apple crates we procured cheaply from an orchard about thirty years ago now.
Cool and moist are the key words. An unheated cellar is ideal. Wait until the cellar temperature is 45 degrees or less, then harvest and bring in your spuds in crates or baskets. Ours used to last until the next harvest…until I installed a gas furnace down there. Even now they easily last till planting time.
Lacking that; look around and use your imagination. They need to be kept above freezing. (Potatoes that are frozen have an unpleasant sweet taste. That disappears though after they defrost.) A high moisture level keeps them from prematurely shriveling. As close as you can come to those two guidelines the longer your potatoes will last well.
Saving Seed for Next Year
You may decide to save yourself the expense of buying seed potatoes each year by saving some of your harvest to re-plant.
If you do, you can also improve your potatoes. Growers of seed potatoes sell them from their whole crop, not just their best specimens. They grade their spuds and sell the smaller as seed. But that has no regard for the individual variations between plants of the same variety.
As you harvest, and set aside each plant’s tubers, you’ll notice there is a difference in the quality and quantity of the yield of each plant. If you saved from all plants, odds are your harvest will be about the same or less.
If, however, you do what gardeners and farmers have done for millennia, and save from only your best, highest producing plants, over a few seasons you will see your yield go up and the ratio of large to small tubers go up too.
And as another benefit, you are selecting plants that did well in your ‘micro-climate’ as they like to say now.
Choosing Your Seed Stock
As you stand there staring at your rows of potatoes on the ground after harvest with a pail in your hand to gather up seed; look, really look, at them. You’ll see differences. You want to select plants with a big yield of big tubers, not many or any small ones. And they must be the right shape. Look at the photos below. They are a better guide than words. Avoid weird shapes, spuds pointy on one end (except with fingerlings of course; they’re pointy on both ends). If you re-plant the weirdos, in a few seasons your seed will “run out”. (I.e.: no longer provide a decent yield.)