Potatoes take up a lot of space in the garden. I have tried to minimize that by digging trenches instead of hilling the soil around the plants, but every dog and deer in the neighborhood will walk through a trench. They also fill with water in the spring, and my seed potatoes rot. Solution? Grow them in containers!
Many seem to enjoy growing potatoes in a garbage can container, but I purchased a few plastic pots that I found more attractive for the deck. These were imitation tera cotta, the kind meant to resemble clay pots. I thought the saucer on the bottom would both keep the deck clean and support proper drainage. Well, I ended up drilling larger holes right through the saucer anyway. It is important that the seed potatoes, which will be near the bottom of the container, not sit and soak (ie, rot) in water that can’t drain away.
What are seed potatoes? They aren’t seeds. Seeds come from flowers. However, potatoes are usually grown through vegetative propagation instead of seeds, making clones of the original potato plant. A potato will sprout at the eyes to grow a new plant. They may sprout in the bag from the grocery store, but these sprouts are pretty puny if they happen. This is because the potato industry sprays them with chlorpropham (CIPC) to inhibit sprouting and so increase their shelf life. However, one can use organic potatoes as seed potatoes, or purchase seed potatoes from a garden store or catalog.
I like to chit my seed potatoes. Not everyone does, but I believe it can give me a week to a week and a half jump on the season. This means I set my seed potatoes on a plate in my unheated veranda, while it is still too cold to plant them outside. In the light, they will start to sprout. I turn them occassionally to make sure all the eyes have a chance to sprout. In three to four weeks, the new stems (not roots, stems!) are nice and green and sturdy and ready to grow.
Now it is time to cut the sprouting seed potatoes into pieces for planting. Cut the potato like a 3-D puzzle, containing one or two eyes on each piece. Small seed potatoes can just be planted whole. Let the pieces cure in the air for a couple days before planting. This allows the edges to dry out a bit to keep the new plants healthier.
Finally, time to plant. Add four to six inches of potting mix to the large container. Do not even think about filling it up yet! Place the seed pieces, growing green stem up, on top of the soil in the bottom of the container. Add some more soil mix just to cover, again, don’t fill the container all the way yet. Water, and look again in a few days.
The potatoes will grow quickly. When they are a few inches high, add more soil to just barely cover them up again. I layer straw, too, to keep the pot from becoming too heavy. Repeat, until the soil level in the container is at the top. At this point, the potato plants will grow into lovely things, and will probably bloom in late June or July. In the garden, this signals a time to sneak a few new potatoes out for a tasty treat. In my containers, I just enjoy how my food blooms. In another month, the foilage will yellow and wilt and start to die back.
The dead foilage signals harvest time, and a fun one to do, too. In the garden, I have to use a shovel and dig them up, usually injuring a few potatoes in the process. From a container, however, I can just dump them out like a treasure hunt! Choose an overcast, but dry day to harvest. Drag the container and a few small children to a spot in the garden and simply pour the contents onto the ground. Children love searching in the dirt for each spud, and the soil mixture will enrich the garden. Let the potatoes sit on the ground for a couple hours to dry off. Not in the sun though, as sun might cause them to turn a little green.
If you have enough potatoes to store, let them cure for a week or two. The potato skin will heal over any cuts and bruises if left to sit in the dark with ~55-60 degree temperatures. They can then be stored in cooler (and dark) temperatures of 35-40 degrees to keep them from sprouting. These conditions will help them last through the winter, if they aren’t eaten beforehand. Mine never last that long!