In light of the 2016 $1 million potato photo sale, I thought I would share the amazing story of potatoes.
Food storage and geophytes
Potatoes are tubers. Tubers are are type of geophyte. Geophytes are plant organs used to store food and water. They are also used in asexual reproduction. There are several types of geophytes: bulbs, corms, and everything else. That “everything else” is what we call tubers. Potatoes and yams are stem tubers. Stem tubers can emerge from modified stems. These stems can start out as stolons or rhizomes. Stolons are stems that grow at or just below the soil surface as “runners”. These “stems” are converted into adventitious roots at the nodes and what would have been a bud above ground becomes a spud below. Rhizomes are 'runners' that connect a parent plant to its offspring.
A modified stem
The “eyes” seen on a potato are actually stem nodes. Within each potato, you will find the same plant cells you would find above ground: vascular bundles, pith (spongy tissue), and cortex (outer tissue). Now here’s the funny part. While our standard spud grows from stem tubers, sweet potatoes grow from root tubers. The internal cell structure is very different. Root tubers have no nodes. That is why sweet potatoes have a more elongated form. At one end, you will find crown meristem tissue, which grows into stems and leaves. At the other end, called the distal end, the tuber produces roots. But enough of that, let's start growing some potatoes!
Commercial potato farming
Growing potatoes is surprisingly easy and I urge you to give it a try. In his book, The Botany of Desire, Michael Pollan describes how one potato farmer would not feed what they had grown commercially to their family, due to all the fungicides, herbicides and pesticides that are applied to commercial crops. That was a little misleading, since those chemicals are heavily regulated and rarely last long enough to be found on the food we eat. The real reason behind growing an untreated patch of potatoes was so they could enjoy the potatoes whenever they wanted them, rather than having to wait for the chemicals to dissipate. Personally, I don't use chemicals.
How to grow potatoes
While potatoes can can certainly be grown from spuds bought at the grocery store, this is a bad idea. Foods bought in the store are safe for human consumption, but they are not guaranteed to be free from common garden pests and diseases. You are far better off buying certified “seed potatoes”.
The easiest way to grow potatoes is in a barrel, raised bed, or in a tower. If potatoes are planted in the ground, you will be finding rouge spuds for many years. Also, digging them up from the ground is, let’s face it, work. Growing potatoes in containers makes harvesting significantly easier and they make nice summer patio plants!
To begin, fill the bottom of the container(s) with 4" of loose, moistened soil. Cut seed potatoes into 2 inch chunks, making sure that each chuck has several eyes (small seed potatoes can be planted whole). Place the chunks 6" apart and cover them with 3" of moistened soil and repeat the process until the container is filled. Water lightly and be sure to place planters where they will get lots of sun. To build a tower (which works nicely for strawberries and herbs, too), simply take a section of chicken wire or hardware cloth and create a cylinder. Landscape cloth can also be used, but it may fall over. You can also grow potatoes indoors, near a window, if it gets enough light. Potatoes need loose, well-drained soil and frequent, light watering. Never let potato plants sit in water, they will rot. Potatoes use a lot of nitrogen and potassium, and they prefer acidic soil (as low as 4.8 pH).
At first, it will look as though nothing is happening. As a gardener, you know the value of patience. With time, water and sunlight, tubers will send out roots and stems that will pull nutrients from the soil and create carbohydrates out of sunshine. (Don’t you just love photosynthesis?) Before long, the container will be filled with lush, green growth. Aside from occasional watering and feeding (aged compost works great!), that’s all you have to do until it completes the season’s life cycle.
Eventually, the lush above ground growth will start to die off. When it starts looking ragged, dump the contents of the container out on a tarp and remove the mature potatoes. Now comes the really cool part: mix the remaining soil with some aged compost and do it all again with the immature spuds! I have been growing potatoes from the same batch of seed potatoes since 2011. To me, homegrown potatoes taste far better than store bought spuds.
Pests and diseases of potato
We’ve all heard about the Great Potato Famine. Over one million people died and another two million abandoned Ireland, all because of potato blight. Potato blight causes the tuber to rot in the ground. Other potato diseases include charcoal rot, corky ringspot, cucumber mosaic, curly top, fusarium wilt, leafroll, pink rot, sclerotium stem rot, cankers, verticillium wilt, and white mold. Many of these diseases can be prevented with good drainage and proper spacing between plants.
Common potato pests include aphids, beet leafhoppers, cutworms, flea beetles, potato psyllids, potato tuberworms, silverleaf whiteflies, Colorado potato beetles, Jerusalem crickets, and wireworms. But don’t let these threats stop you from creating your own potato patch.
Start your own potato patch today!
You can grow a surprising amount of food in your own yard. Ask me how!