Growing potatoes can be a challenge but it is a rewarding crop with many uses. Potatoes are not roots, although they are often thought to be. They are tubers and form on the underground portion of the stem. In frost-free areas, potatoes grow well from August to June. If you live in a frost-heavy area, it is best to limit your potatoes growing from September to March, before the chance of frost.
Potatoes grow from ‘seed’ tubers. You can cut your seed potato to make it go further as most have more than one ‘eye’. The eye is the spot on the potato out of which root will grow, often appearing as a small hole or dimple. If you are cutting, make sure each piece has at least two eyes. Place your seed potatoes or cutting in a tray in a cool and airy place to encourage sprouting. You can also use an egg carton. This must be done at least 24 hours before you plant to allow the cutting to ‘scab’ and dry out. This helps prevent disease and rot.
Preparing Your Soil
Potatoes do well in loose, well draining soil. You should avoid any soils with clay as they interfere with the development of the tuber, preventing well-sized vegetables. Sandy and loamy soil is best with added compost, or composted manure. Once you have identified the area in which you will grow potatoes, you should dig deep into the ground, breaking up the soil and removing weeds.
There are a number of ways in which you can grow potatoes, depending on what you have available to you and the size of land you wish to use.
These must be 15cm wide and deep with about 60 to 75cm between them. At the bottom of your trench, a layer of compost should be added about 5 to 10cm deep and incorporated with about 5cm of topsoil. Your seed potatoes should not come into direct contact with your composted material, so the topsoil is key in preventing this. Once the pants have grown to about 30cm in height, you can create small ridges or hills around each one to protect it. Potatoes are a space-intensive crop, but most smallholders can spare the space.
You will need 1 to 1.2m tall wire fencing ~ something with sufficient gauge to retain its form, and be used for a few years; wire cutters; some sort of twisty tie; cable ties or thin wire; straw or hay; pure manure-free compost; a water source and seed potatoes.
Use the wire cutters to cut out a section of the fence to create a cylinder container, about 90cms in diameter. Use either twisty ties, thin metal wire, or cable ties to tie the fence ends together. Use straw to create a nest at the bottom of the bin to both help keep in the compost, and to reduce water-loss due to evaporation. If you do it without the straw, just make sure to use a fence with smaller holes to keep the compost from spilling out. The straw naturally supports itself up the sides as you spread it, leaving a large central area for the compost.
Next, shovel in compost and topsoil to a depth of about 30cms and lay the potatoes about every 10-12cms along the very outside of the bin, right next to the straw layer, with the eyes pointed out. Next, it is important to absolutely soak the compost, as it often is on the drier side. Do this after every potato layer is planted. It is important to keep the bin moist, from top to bottom.
Stack two to three tyres on top of each other, filling them with a topsoil and compost mix to just over half the depth of the tower. Place four or five seed potatoes on the soil with the eyes or shoots pointing upwards. Cover with soil and water thoroughly. As plants grow, add another tyre with a layer of soil to support the young plants. This will encourage larger plants, and more potatoes.
Grow bags, often made from heavy polypropylene, felt or canvas, work in much the same way as towers by containing the soil. These can be useful to prevent mole damage to your plants. One way to use these bags is to roll them down, fill the bottom with about 5cm of soil and compost mix and plant your seed potatoes. Then cover with just enough soil to cover the tops of the tubers. Water thoroughly, continuing to add soil as the young plants grow. Unroll the bag as you need to, to add height and contain the new layers of soil.
Regardless of what method you have chosen to grow your potatoes, there will come a time to harvest. Wait until the plant wilts, almost to the point of looking dead, then pull the whole plant out. If you are using a tower or bag, tip the tower or bag over, emptying out the contents and harvest like that.