Potatoes are among the most productive vegetabes for home gardens. For every pound of seed potatoes you plant, expect to harvest three to five pounds of spuds in return. That’s a great investment! Plus, with the long storage life of potatoes and the myriad of ways you can prepare them, they are a must-grow crop for many gardeners. And, to sweeten the deal even more, potatoes are a simple crop for beginner gardeners to grow. Every potato-growing adventure starts with seed potatoes. In this article, we’ll look at what seed potatoes are, how to plant seed potatoes, and how to grow them successfully – no matter how much, or how little, space you have to grow.
What are seed potatoes?
Seed potatoes are not actually seeds at all. Instead, they are simply potato tubers that are used for planting. Most often, they are saved from last year’s harvest and stored over the winter under exacting conditions to keep them firm and disease free. Rather than saving some of your own harvest for replanting the next year, I recommend purchasing new certified disease-free seed potatoes at the start of each growing season.
Potatoes are prone to many diseases (bacterial, viral, and fungal), including potato scab and potato blight, that can easily be introduced to the garden when planting your own saved tubers. White potatoes, red potatoes, or those with yellow flesh or red skin are no different than spuds with any number of different colored skins or interiors. Purchasing and planting certified seed potatoes is the only way to ensure a “clean” crop. Certified seed potatoes are guaranteed to be free of disease, and they have not been treated with the anti-sprouting chemicals often used on grocery store potatoes.
Why cut seed potatoes for planting
New potato plants sprout from the buds (called eyes) on the surface of potatoes. The eyes appear as dimples in the potato’s skin. You’ve probably had a potato sprout new growth if you’ve left it in the pantry too long. Each eye has the potential to grow into a whole new plant. Because of this, seed potatoes are typically not planted whole. Instead, they are cut up into pieces prior to planting to yield more plants from each seed potato.
Cut seed potatoes into pieces that are about the size of a golf ball. Each piece should contain at least 2 eyes. You can force a seed potato to sprout prior to cutting it up by putting it in a well-lit place at room temperature for a few days (just not in direct sunlight). Or you can cut the seed potato first, and then let the sprouts develop under the ground. This is my preferred method as it is much easier to plant an unsprouted seed potato than one that’s developed fragile new sprouts that are easy to break off during the planting process.
How to cut seed potatoes for planting
Using a clean knife, cut the seed potatoes into pieces two to three days before you plan to plant them. Be sure to wait until your last frost date has passed. Whether or not they have sprouted, let the seed potatoes sit at room temperature in a single layer so their cut tissue can callus over. This prevents soil-borne diseases from entering the seed potatoes when they are planted.
One pound of seed potatoes yields about 8 to 10 seed pieces for planting. That’s enough for a 10 foot long row if the pieces are spaced 12 inches apart. When first figuring out how to plant seed potatoes, I determined that spacing a little closer works too. I space my seed potato pieces about 10 inches apart when planting.
Where to plant
There are three main ways you can plant seed potatoes. They can be planted directly into the ground (or in a raised bed); they can be planted in containers; and they can be planted under straw. Rotate crops so your potatoes are not planted in the same spot each season. Regardless of which seed potato-planting method you choose, select a site that receives at least 6 hours of full sun per day and wait until soil temperatures have warmed before planting and soil moisture levels are good. Let me walk you through each of these three methods so you can determine how to plant seed potatoes in your own garden.
How to plant seed potatoes in the ground
If you want to know how to plant seed potatoes in the ground, the first step is to pay attention to the depth and spacing of your seed potato pieces. When planting seed potatoes in the ground, either dig an individual hole for each cut piece of seed potato or use a garden hoe to dig a trench to plant several of them in a row 10 to 12 inches apart. The hole or trench should be 4 to 5 inches deep. If you plan to plant multiple rows, space the rows 18 to 24 inches apart.
Regardless of whether you plant in rows or holes, when growing seed potatoes in the ground you’re going to want to hill your potato plants two or three times through the growing season with several inches of soil. The deeper potato plants are grown, the more area there is for tuber production. But, planting the seed potatoes too deeply from the start can cause them to rot before they sprout. At the very least, it makes harvesting very difficult at the end of the growing season because the potatoes are buried so deeply.
Instead of initially planting the seed potatoes deeply, gardeners overcome this challenge by mounding excess dirt up around the plants as they grow. This process is known as hilling. Basically, every three to four weeks, use a shovel or hoe to pile nearby soil up against the stems, covering the plants so just a few leaves stick out the top. Don’t worry about burying them too deeply; as long as some of the plant is visible, it will keep growing (plus, it keeps the weeds down).
Hilled in-ground potatoes produce bigger yields. Plus, the developing tubers are kept in the dark, which keeps them from turning into green potatoes (and potentially making you sick with the solanine they contain. More on how and why that happens here.).
How to plant seed potatoes in pots and grow bags
You may also be wondering how to plant seed potatoes in containers. This second method of growing spuds is great for folks with limited space or no in-ground garden. It’s easy to do, and though the yields are often slightly smaller than growing seed potatoes in the ground, it’s the perfect option for anyone who is looking to save labor, too.
To plant seed potatoes in a container, begin by sourcing the right kind of container. When it comes to growing potatoes in pots, the bigger the better. Each piece of seed potato needs at least 2.5 – 3 gallons of potting soil to grow into a full-sized plant. That means if you use a container around the size of a 5-gallon utility bucket, you can plant 2 seed potato pieces inside. Larger pots can host even more seed pieces. Be sure the container has drainage holes in it and use a high quality potting soil with a fertilizer mixed 50/50 with compost. The general potting soil mix found in our DIY Potting Soil Recipes post is an excellent choice. You can also purchase bagged potting soil and bagged compost and mix the two together.
When thinking about how to plant seed potatoes in containers, you should also consider using fabric grow bags for the job. These lightweight containers drain easily, are inexpensive, and keep plant roots from circling inside the pots. Some brands even have designs with flaps that open on the side of the grow bag to make potato harvesting a snap.
In this video, Tara shows you how to plant potatoes in a unique container growing system.
Just as you hill potatoes in the garden to ensure there is maximum space for tuber production, you should also perform a similar task when growing seed potatoes in pots. At planting time, only fill the container with soil mix one-third of the way. Nestle your seed potato pieces into the soil and cover them up. As they sprout and grow, gradually add more soil mix to the container every week or two until the pot is filled to within an inch of the upper rim. Then stop adding soil and keep the container well watered as the plants continue to grow.
How to plant seed potatoes in straw
Growing seed potatoes in straw is an excellent and easy way to get lots of spuds with minimal work. If you’re wondering how to plant seed potatoes in a way that makes them easy to harvest and keeps the spuds clean, then growing in straw is the way to go.
To plant seed potatoes in straw, prepare an in-ground garden bed or a raised bed for planting. Then, nestle each piece of seed potato down into the soil by no more than an inch or so. Some gardeners who plant seed potatoes in straw don’t even bury them at all; they simply toss the pieces on top of the soil. Once the seed potato pieces are placed, cover them with 5 or 6 inches of loose straw. As the plants grow, add more straw to the top, covering all but the very top leaves of the plant, until the bed has 8 to 10 inches of straw. Though the layer of straw serves as an excellent mulch, keep the bed well-watered through the growing season.
When the mature potato vines die at the end of the growing season, wait to weeks then peel back the straw and collect the potatoes. Easy cheesy! If you’re deciding how to plant seed potatoes in a raised bed, straw planting is an excellent option.
Which method is best for you?
Now that you know how to plant seed potatoes in the ground, in containers, or in straw, it’s easy to see which method is best for your space. Regardless of which technique you choose, a hearty potato harvest is right around the corner. Just be sure to protect your plants from pests like Colorado potato beetles by covering the plants with floating row cover.
Not sure when your potatoes are ready for harvest? Check out this great article on our website about how and when to make your potato harvest. It walks you through harvesting both new potatoes and mature spuds using a digging fork or shovel.
This video will also provide a primer on when and how to harvest your potatoes.
And check out this article for information on a unique small-space potato-growing method that uses a wire cylinder lined with newspaper to grow a bumper crop of spuds.
For more advice on growing great veggies, check out the following articles:
How to grow sweet potatoes
Growing tomatoes from seed
Tips for growing healthy zucchini
Cucumber plant problems
Growing carrots from seed
Do you grow seed potatoes every year? Tell us which method works best for you in the comment section below.