This year I was given two types of seed potatoes: Harvest Blend and White Superior. I have grown potatoes before in my Virginia garden and they were very tasty. This year, I am going to grow these potatoes in fabric containers called Smart Pots. Any fabric container or even a plastic container with holes for drainage will do, I just happen to have a few large Smart Pots.
Potatoes are in the same family as tomatoes and eggplants but gardeners start growing them in the spring, as opposed to their warm-season cousins. Although you hear that potatoes are started on St. Patrick’s Day, that might only be true for the Irish. It does not always work for gardeners in the Washington DC area. We just had snow so I waited until this past weekend when I was closer to my last average frost date. I have read that the time to plant potatoes is when dandelions are blooming; sure enough, my dandelions were blooming this past weekend.
Some of the independent garden centers will sell a few varieties of potatoes but you get a much wider selection if you contact mail order companies. In fact, there is tremendous diversification of the tuber itself: there are white, blue, red, purple or gold colored tubers–round, gnarly, slender, large or small. In terms of cooking, tubers can be mealy like a Russet (good for baking but disintegrates in a stew) versus waxy like a Yukon Gold (holds its shape). The tubers vary in maturation days, there are early, mid, and late season varieties, thus extending the harvest from June to August. Interestingly, the foliage, that is, the above ground part, does not vary. The plant grows to a few feet tall, flowers, and dies, signaling the time to dig up and harvest the mature tubers.
To grow potatoes, purchase “seed potatoes,” which are not true seeds but the “starter” tubers one plants in the soil. It is best to start with seed potatoes that are certified as disease-free, instead of planting a grocery store potato. The shoots arise from the “eyes” and additional tubers appear along these shoots as they grow. Seed potatoes should be the size of an egg with at least two eyes. If the seed potato is this size already then plant the whole thing, eyes up. If the tuber is large, can cut into sections, each with at least two eyes. I have read differing opinions about whether you should let the cut end callous (to prevent disease); it seems some people cut and plant while other cut, callous, and then plant.
I planted my potatoes in two Smart Pots, which are ventilated fabric containers (no need to poke holes in the bottom). This is a great way to grow potatoes if you do not have a lot of land, if your garden soil is too compacted, or if you want to encourage kids to get involved. For potatoes, use at least a 20-gallon size Smart Pot with at least a 15-inch height. Estimate 4 plants in this size and more in larger sizes. I spaced mine about 6 inches part so I planted four Harvest Blends in the medium container (foreground in photo) and 5 White Superiors in the larger pot (background in photo).
I used potting soil that already had a slow-release fertilizer. Because potatoes are heavy feeders, I will supplement with a liquid fertilizer later in the season.
I poured 3-4 inches of the soil in each container, watered, placed the potatoes on top, eyes up, added 3 more inches of soil, watered again, and inserted a plant label. I rolled down the sides so they would not turn inward and prevent rain from reaching the plants.
One advantage to containers is that you can place them anywhere, a deck, a porch, a driveway, even on grass. Another advantage is that you don’t have to worry about crop rotation if you have been growing tomatoes, peppers, and eggplants in the garden. My containers are in full sun on the deck so I can easily keep an eye on them. Because potatoes are susceptible to Colorado potato beetles, I have to be able to easily check the underside of leaves for the yellow/orange eggs.
Potatoes require an inch of water a week so I need to be able to water easily and often, which I can do with a hose on the deck. However, the foliage is susceptible to fungal diseases so I will water by putting the hose nozzle into the bag, not spraying the foliage and not watering in the evening.
In a few weeks I will have to “hill” the plants. The new tubers grow up from the seed potato. As the shoots grow (now stems), and more tubers appear, these new tubers have to be covered with soil. Tubers exposed to light become green and bitter. (This also is a tip for storing store-bought potatoes, keep them out of light in a cool place but not in the fridge). When the stems have grown about 8 inches, I will add about 4 inches of soil and repeat the process again, unfolding the sides as I add more soil. This process of adding soil is called “hilling.”
In early summer, when the plants flower, I can harvest immature tubers by putting my hands in the soil and pulling egg-size tubers out (leaving smaller ones in). This immature stage is what we buy as “new potatoes” in the store. New potatoes have a very thin skin and do not keep. They have to be eaten soon and usually they are boiled and mixed with parsley, chives, and butter.
In mid-summer, probably June, the potatoes will have matured. When the leaves yellow and die, I will stop watering, wait two weeks, and then dump the container. I will dump the soil on a tarp. I can either use the soil to start a new garden bed or put back in the containers to plant bush beans.
One term that comes up with potatoes is chitting, which is common in England but not so much so here. Chitting is the process of “pre-sprouting” the tuber before planting to give the plant a head start, much like starting tomatoes under lights in the house before May. Chitting affords an early harvest but takes space and time.
I did not chit my potatoes for two reasons. By the time I received them they had already started to sprout. The tubers were small and slightly shriveled. They must have been in a place that was too warm. But if I had purchased tubers, I probably would not chit because I do not have a need to have potatoes a few weeks earlier. Plus one has to consider the space this would take and available windows.
If you are interested in chitting, place your tubers eyes up in an egg carton. Put next to a window in a warm place (the usual heated house). The type of grow lights you use for starting seeds are not necessary. After they have sprouted (like your old potatoes in the vegetable bin), you can plant them outside. If the tubers are large, cut into pieces the size of an egg with at least two eyes.
I am looking forward to growing potatoes in Smart Pots this year — freshly grown potatoes taste better than store-bought potatoes.