For many years, I avoided growing potatoes because I thought they needed a lot of space and they weren’t practical for backyard gardens. I was so wrong! Potatoes are not only a great addition to the backyard garden, but they are really easy to grow. They are a cold weather crop that grows well in the northern half of the country. Potatoes are hardy enough that they can survive a light frost. Aim to plant the seed potatoes in early spring, a few weeks before your area’s last frost date.
Anatomy of a potato plant
A potato is a tuber. A tuber is a thickened underground food storage unit to feed the plant. The part of the plant that is above ground consists of leaves, flowers and sometimes small fruits. The fruit of a potato plant are small, round & green and look similar to a cherry tomato. They are not edible. The potato fruit has high levels of solanine, which can make humans very ill. Below the ground are the roots and the tubers (potatoes) which are attached to the main underground stem by stolons.
Preparing the ground
Potatoes like rich, organic, loose soil. If the soil is hard or compacted the tubers will not grow at all or they will grow misshaped. If you have the space and good soil, potatoes can be planted in rows right in the ground. I grow my potatoes in a raised bed so I can control the quality of the soil. Potatoes can happily grow in large containers, bags, towers and more! Be sure to practice crop rotation when growing potatoes. To prevent plant diseases from accumulating in the soil, do not plant your potatoes where members of the nightshade family have grown in the previous two years (tomatoes, potatoes, peppers, eggplant)
Preparing the seed
When growing potatoes, you want to start with quality certified seed potatoes. Can you grow potato plants from potatoes you bought at the grocery store that have sprouted? Yes, you *can* do it, but you won’t get as good results. Store bought potatoes are treated with chemicals to help preserve them and keep them from sprouting which is obviously not good if you want them to sprout! If you have to use store bought potatoes, at least choose organic so they will be untreated. Certified seed potatoes will also be guaranteed to be disease free. There are several diseases potatoes are susceptible to, they can not only effect the current year’s crop, but could also contaminate your soil for future years. It’s best not to risk it and just start with seed potatoes. If you order your seed potatoes and they come before you are ready to plant them, store them in a cool, dark location (I use my refrigerator). This will keep them from sprouting prematurely. Before cutting them, let the potatoes sit out at room temperature for about a week. You should cut each seed potato into several pieces. You want to ensure you have at least two eyes per piece. After cutting the potatoes up, lay them on some newspaper and let them sit for about a week so the newly cut pieces can form a protective “scab”. It will help them retain moisture and prevent rotting.
Dig a hole about 4 inches deep. Place the seed potato in the hole, with the eyes facing up. Space plants about a foot apart. Cover with soil and keep the area moist. It will take about 2-3 weeks before you’ll see the plants emerging from the ground.
When the plants are about 6 inches tall, mound up the soil around the stem. This will support the plant, but more importantly you will be sure all the tubers are covered. If tubers form near the soil and get exposed to light while forming they will turn green. Green potatoes are very bitter because a poisonous sustenance called solanine is building up in the potato’s flesh. Every two – three weeks remound the soil around the plant. Many gardeners will add a thick layer of straw around the plants. The straw helps retain moisture and helps keep the tubers in the dark. It also keeps the soil temperature down. Potato tubers will grow the best in soil temperature between 60-70 degrees. The hotter the soil gets, the less the tubers will grow.
When the plant begins to flower, this is when peak tuber growth is happening below the ground. If you want small, new potatoes, you can harvest 2-3 weeks after the plant begins to bloom. For full size potatoes wait until the plant dies (usually late August/early September). Be careful when digging for potatoes, you don’t want to puncture them! Brush the dirt off, but don’t wash them until you are ready to use them. Store potatoes in a cool, dry, dark location.