Potatoes are one of the easiest crops to grow in your garden if you follow these simple tips.
About one-third of Vermont gardeners grow their own potatoes, according to a recent survey. There are several ways to grow potatoes easily, and by following a few key tips, you can have success. If you grow your own potatoes, you can have access to a variety of flavors that you may not be able to find otherwise. Furthermore, you can be sure that the potatoes you are eating are safe.
Growers who produce crops commercially can encounter various problems when attempting to grow them in large fields. They often combat these issues with the use of chemicals. This means that store-bought potatoes are one of the vegetables that contain the most pesticide residues, according to the Environmental Working Group. If you purchase local organic produce, you can be assured that the farmers are not using any harmful chemicals; however, even organic farmers may use chemicals that are not necessary for home gardens.
Types of Potatoes
The vast array of potato varieties you can find for your garden far surpasses the selection you’ll find in stores or from many local growers. There are many different types of potatoes that can be distinguished by their use, size, or color. The flavor and texture of potatoes can also vary.
- Russet types are the potatoes you see in stores with the brown skin, large elongated shape, and are used for baking
- “New” potatoes are harvested small and immature and aren’t necessarily red as often believed
- Red potatoes (on the outside) can be red, white, or yellow on the inside
- White potatoes (on the outside) can be white or yellow inside
- Purple potatoes, both outside and inside, may turn blue on cooking
- Fingerlings are shaped like fingers or stubby carrots
Popular varieties grown for early-season harvest include:
- ‘Irish Cobbler’ has a tannish skin and irregular shape. It works well for boiling and mashing.
- ‘Norland’ has red skin and is known to be resistant to potato scab.
- ‘Mountain Rose’ has red skin and pink flesh; it is known to be resistant to some viruses.
Popular varieties grown for mid-season harvest include:
- ‘Red Pontiac’ has red skin. It is considered one of the easiest red potatoes to grow.
- ‘Viking’ is a very productive red-skin potato.
- ‘Chieftan’ is a red-skin potato known to be resistant to potato scab. It stores well.
- ‘Yukon Gold’ is a very popular thin-skinned potato with yellow flesh. It has no eyes.
Popular varieties grown for late-season harvest include:
- ‘Katahdin’ has tan skin and is resistant to some viruses.
- ‘Kennebec’ is another tan-skinned potato. It is bred to be resistant to some viruses as well as late blight.
- ‘Elba’ is a tan-skin potato with large round tubers; it resists blight and potato scab.
If you want to try growing some unique potatoes, look for these:
- ‘French Fingerling’ is a long, slender, red-skinned potato that doesn’t need peeling. They are best suited for roasting, baking, and steaming.
- ‘All Blue’ is a medium-sized potato with an unusual blue skin and flesh that keeps well. Suited for sautéing steaming, or mashing.
How to grow potatoes
If you want to grow potatoes from true seeds, similar to tomatoes, you should sow them indoors about 8 weeks before the last frost date. More often, potatoes are started from “seed potatoes” which are not actual seeds but chunks of potatoes with sprouts, buds or “eyes”. You will find these in garden catalogs and stores in spring, but not on the seed racks. Look for certified disease-free seed potatoes. Do not use store-bought potatoes as these usually have been treated with an inhibitor to prevent sprouting and might have diseases.
Cut potatoes with eyes into small pieces
Potatoes are tubers, which are storage organs. Plant golf-ball sized tubers of seed potatoes directly. Tubers that are larger should be cut into pieces that are about 2-inches thick. Each piece should contain a couple of new shoots, or “eyes”. The ideal size is still small, just sprouting, without any stems. Do not handle the plants roughly as this will result in the breakage of delicate stems. Before planting large sections of a tuber, allow them to harden in a cool area with good ventilation for a day or two.
When to plant potatoes
You should plant your seed potatoes when the daffodils are blooming and the ground temperature is at least 50 degrees Fahrenheit, which is usually around three weeks before the last frost date. Frost can damage new shoots above ground, but it won’t hurt the seed pieces in the ground. If you see new growth on your potatoes and a frost is expected, cover the new growth with a frost cloth, a plastic milk jug, or something similar. Learn how to determine your last frost date.
When growing potatoes, keep in mind that you want the new potato tubers that form to be in the ground, out of the light, so they don’t turn green.
There are several ways to keep potatoes in the dark underground. Traditionally, seed potatoes are planted about 3-inches deep in trenches, with rows 3-feet apart. They should be planted a foot apart in the trench. After the plants have grown for a while, you pile more soil on around them, covering about half to two-thirds of the plant. If you are using the straw method, you should first cover the soil with a couple inches of compost. After that, you can apply subsequent layers of straw. If you have mice in your yard or nearby, it is not a good idea to use straw, as it may result in lower yields.
A technique similar to straw hilling begins with a one foot deep trench. The seed potatoes are planted at the bottom of the trench, about three inches deeper than usual. As plants grow, you should add a few inches of compost, then just straw, and eventually fill in the trench.
For best results, grow your potatoes in soil with an acidic pH between 5.0 and 6.0. New potato growers should be aware that potatoes grown in alkaline soils are more likely to develop scab, a condition that causes rough, scaly patches on the surface of the potato. Potatoes don’t like particularly rich soil. As long as there is a good amount of organic matter in the soil and the pH is neutral to acidic, the potatoes should be fine. The soil needs to be loose and well-draining. If you have soil that is mostly clay, you will need to loosen it up and prepare it down to the depth where the potato tubers will grow.
Potato plants rely on a steady water supply. Be sure to give the plants at least one inch of water per week. Potatoes are especially sensitive to drought conditions when they are flowering, as that is when the potatoes form tubers. Mulching around the plants can help retain moisture.
Temperature and Humidity
You should not plant potatoes until the soil temperature reaches at least 45 degrees Fahrenheit, and it is better if the soil temperature is 50 degrees Fahrenheit. Summer crops do best in areas where the summers are cool, as the potato tubers grow best when the soil temperature is 60 to 70 degrees Fahrenheit, and they stop growing when the soil hits 80 degrees Fahrenheit. Placing a thick layer of straw around the plant acts as a mulch and can help cool the soil by up to 10 degrees Fahrenheit. In areas where summers are hot, potatoes are often planted as a winter crop. Potatoes do not have a preference for air humidity.
You should fertilize your potatoes with an organic, slow-release fertilizer when you plant them. Give a feeding of diluted liquid fertilizer or fish emulsion every couple of weeks.
Seed potatoes aren’t really seeds at all. These potatoes are specifically bred to yield more potatoes. They start producing shoots from the potato eyes. This usually happens when you store potatoes in the kitchen for too long.
You can plant seed potatoes whole or cut them into pieces, making sure each piece has one or two eyes (or three). Gardeners often allow potato pieces to callus over by leaving them exposed to air overnight so they don’t rot. A fungicide in powder form can also be purchased to prevent the wood from rotting.
New potatoes are small, immature potatoes. You can pick a few of these once the plant is around one foot tall, which is 50 days after planting. The new potatoes will be ready to harvest when the plant is in full bloom. Feel around the soil near the plant until you find the root ball. Gently lift the plant out of the ground.
The average wait time for potatoes to reach their full size is two to four months (up to 120 days). The crop is ready to harvest once the tops of the plants die off. You can leave the potatoes in the ground for a few weeks longer if the ground is not wet.
It’s important to be careful when harvesting food by hand or with a shovel or spade. To find the round or oval treasures, turn the soil over. Piercing potatoes with a fork is a great way to get them to branch out. Damaged potatoes are not going to last for a long time, but you can still eat them.
Growing Potatoes in Containers
Growing potatoes in a container is less complicated than hilling and it doesn’t take up as much space. A tall container, such as a garbage can, whiskey barrel, or five-gallon pail, can be used to grow potatoes. Planting bags designed for this purpose are also an option. Choose a container for your plant that has drainage holes in the bottom, and raise the container up a few inches if it is resting on a hard surface so that any excess water can drain away.
To plant potatoes in a container, add six inches of fast-draining high-quality potting soil to the bottom of the container and mix in an organic, slow-release fertilizer. Then, spread out your seed potatoes and cover them with a few inches of soil. Put the container in a sunny spot that gets 6-8 hours of sunlight each day. Keep the soil moist, but not too wet. You should continue to add potting soil to the container as the plants start to grow.
Apply a diluted liquid fertilizer every couple of weeks to your growing potatoes. Container-grown potatoes need a lot of water. Usually, plants that are grown in containers need more attention in terms of feeding than those that grow in the ground.
Pests and Diseases
Bacteria is one of the most common causes of “scab” in potatoes. “Scab” gets its name from the corky dark lesions that appear on the surface of the potato. Potatoes that have a scab on them are still edible but you will need to peel them before eating them. The best way to prevent this organism from growing is to avoid manures and alkaline soils, and to water properly. It is not advisable to plant potatoes in the same spot for three years or where other root crops such as carrots, beets, and turnips have been planted. Some varieties that cannot get scab include Russet Burbank, Norgold, Red Norland, and Superior.
Late blight is a common fungal disease of potatoes, which may also spread to related crops. This is the disease that caused the Irish potato famine of the 1840s. By planting different crops in an area over time, crop rotation can help to avoid diseases, including late blight. This involves not planting the same crops, such as tomatoes, peppers, eggplants, and strawberries, in the same area for three years. If you have had late blight in your garden in the past, do not leave any tubers in the ground or save any from previous years. Also, use certified disease-free seed potatoes. Organic sprays are available to treat this disease.
Colorado Potato Beetles are extremely harmful to potato crops. If present, they can quickly decimate a crop. Unfortunately, they have grown resistant to many chemical pesticides. The organic pesticides diatomaceous earth, azadirachtin, and spinosad are effective against Colorado potato beetles.
- Azadirachtin (Neem) – is derived from the Neem tree of Asia and Africa. It is effective for a couple of days and repeat applications are usually necessary.
- Spinosad is made from the soil bacterium, Saccharopolyspora spinosa. It is effective for about 10 – 14 days.
If your garden is small, the most effective way to get rid of the beetles may be to pick them off the potato foliage. To kill them quickly, drop them into a bottle of water with dish soap.