May 11, 2015

Potatoes are a favorite staple throughout the world. Originating in South America, this unique and important plant eventually found its way to North America and Europe, firmly planting itself as one of the most important crops ever produced.

Yet despite its storied history and its integral part in the rise of modern commercial agriculture, there isn’t one definitive way to grow them. From hilled rows in the garden to a pot on the patio, there’s more than one way to plant potatoes.

Deciding the best method to grow potatoes partly depends on understanding how they form. Unlike what many people believe, new potatoes grow above the seed potato along the stem, not underneath the seed. The mother tuber initially sends up shoots—as you see if your potatoes stay too long in the pantry—while creating a healthy root system. This vegetative stage is important because it determines the overall health of the plant.

The new tubers form along the stem below the soil. If you take a look at a potato plant when you pull it in the fall, you’ll see these swollen spots branching off along the stem. If you had an ideal season, they will all be good-sized potatoes, though it’s common to have a number of underdeveloped tubers.

When you’re planting potatoes, keep this process in mind so you can give your potatoes the optimum conditions for a bountiful harvest. Here are six different potato-planting methods to help you make your decision.

1. Traditional Hilling

Although this is probably the most labor-intensive planting and harvesting method, it’s a tried-and-true technique that hasn’t gone wrong for centuries. Till a trench 6 to 8 inches deep, place the seed potatoes 10 inches apart and cover them. As the plants grow, hill the soil a few inches around the base to ensure the potatoes that form along the stem are adequately covered. Do this more than once throughout the season, allowing the foliage to continue growing above the soil line.

2. Straw Hilling

This is a modified version of traditional trenching and hilling. Plant the potatoes 3 to 4 inches deep, but instead of hilling throughout the season, simply cover the plants with straw as they grow. Eventually the straw will be at least 1 foot deep.

The beauty of using straw is that is makes your potatoes very easy to harvest. For the most part, you just pull back the straw and pick up the potatoes. The major drawback is that if you don’t pile enough straw on top of the tubers, sunlight might reach them, causing sunburn and the subsequent green skin, which is inedible. In addition, in areas where mice are prevalent, you might lose some to the rodents.

3. Straw-Bale Growing

Another option using straw is employing the straw-bale gardening method. “It’s just so easy and so productive,” says Joel Karsten, a straw-bale gardening guru in Minnesota. “Once the bale is conditioned, it’s as simple as making three holes in the bales.”

Karsten says to make the holes nearly to the bottom of the bale, roughly 18 inches deep. Place your seed potato, sprout end up, in the bottom of this tunnel. “It grows up and out of the hole,” he says. When it reaches the top of the bale, simply push the straw around the stem. To harvest, once the plant has died, cut the strings and the potatoes fall out.

One benefit of straw-bale gardening is that you can plant sooner than in the soil. The potatoes grow well in the straw, which becomes very loose as it breaks down throughout the summer. The one consideration is you don’t want to cut corners on the early conditioning process: It needs to be done properly for the system to work its best.

4. Grow Bags and Other Containers

You don’t have to have a large garden to grow potatoes. They do equally well in containers, including the fabric containers often referred to as “grow bags.” The heavy landscape-fabric containers work well because you don’t risk overwatering, as you do with a solid pot.

If you don’t wish to purchase a grow bag, you can use anything from a large, decorative container to a 5-gallon bucket. Marcia Bundi, a level-3 Master Gardener, reminds gardeners to make holes in the bottom of any solid container to allow for drainage.

“You need a couple of inches of good garden soil in the bottom,” she says. Place one to three seed potatoes, depending on the size of the container. A 5-gallon bucket might only take two pieces, while a container 24 inches in diameter could easily accommodate three.

Cover the pieces with 4 to 5 inches of soil, and as they continue to grow, add soil until the stems are covered up to 18 inches deep.

“It doesn’t do any good to cover up that foliage stem,” Bundi notes. “You want the foliage because that’s the energy factory.”

She says to water the potatoes daily to provide consistent moisture, and fertilize with a water-soluble fertilizer. To harvest, simply dump out the potatoes, or reach into the container to gather the new tubers.

5. Potato Towers

These wooden structures are a combination of a raised bed and container. Using wooden slats to make up the sides, you increase the height of the walls as the potatoes grow. They are typically 2-by-2 feet and roughly the same height.

Place a couple of the slats on the walls, and fill the bottom with 3 to 4 inches of garden soil. Place three seed potatoes on the soil, and cover with a few inches of soil. As the potatoes grow, add more boards to the sides and soil to stay within a couple of inches of the foliage top. Some people even add another layer of potatoes. You can do this until the bottom potatoes are under 18 inches of soil.

Keep the tower fertilized and watered throughout the season. To harvest early, unscrew a bottom board and rob a few potatoes. To harvest at the end of the season, just take apart the walls.

The drawback to this method is the cost of the boards (unless you can use recycled materials), as well as the amount of soil you’ll need.

6. Square-Foot Gardening

If you’re looking for a way to grow without much space, soil or effort, the Square-Foot Gardening method, developed by author and retired civil engineer Mel Bartholomew nearly 40 years ago, fits the bill. In a typical SFG bed, 6-inch-wide boards are used to create a 4-by-4-foot box filled with a mix of equal parts of vermiculite, peat moss and compost. The bed is then divided into 12-inch blocks.

“Potatoes and large carrots are the only exception to the 6 inches of soil we use,” says Belinda Jensen, head of operations at SquareFootGardening.com, who loves to grow her favorite staple using this technique. To plant potatoes in the bed, she utilizes a 12-inch-tall “top hat” placed on top of the 12-inch squares to extend the growing space.

“You can place four seed potatoes in a 12-inch square,” Jensen says. “You can add another top hat, if you want. And once you see the sprouting, add more soil.”

To harvest, you simply remove the top-hat extensions and gather the potatoes.

With dozens of potato varieties, there’s nothing like growing your own. Fortunately, with so many different ways to raise a bountiful crop, anyone can enjoy their favorites.



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