Potatoes are almost foolproof. They’ll grow and produce as long as the soil is fertile, water is available, the sun shines, and the plant doesn’t freeze. Growing potatoes in a bag or bucket will allow you to harvest them even if the sun only shines on a cement slab.
How Potatoes Grow
Potatoes are one of the few nightshade crops from which the fruit is not eaten. Though some varieties do produce “potato fruit” or “true seeds,” the fruit is toxic. Instead, the tuber is cultivated, dug, and cooked prior to consumption.
Like all nightshades, potatoes are frost-sensitive. Gardeners may plant them before all danger of frost has passed, and they will be fine if leaves don’t emerge before a light cold snap rolls in, but temperatures below 32 degrees will damage or kill foliage. Gardeners have best results if they protect their plants from freezing weather.
But like other nightshades, stems that are covered with loose soil turn into roots. This is why tomato seedlings are transplanted up to the bottom leaves. A stronger root system supports a stronger plant. With potatoes, it gives them more root from which tubers can grow.
Potatoes that are never mounded-up don’t produce much. A “seed” sunk six inches into the soil only produces tubers in those six inches. But if the stem is covered with dirt as the plant reaches up, those six inches can extend to twelve or eighteen. A pot of potatoes placed on a driveway will never grow down. But by growing potatoes in a bag or bucket, five gallons of soil can be filled in to surround the stem as it reaches up. Eventually, the gardener has up to two feet of soil potential.
Eventually, the plant dies. Growing potatoes doesn’t go on forever. Though new potatoes can be harvested when the plant is semi-mature, they store best if gardeners wait until the tops die back. Then the entire bag can be upturned into a wheelbarrow. Potatoes are harvested and the dirt is stored until next year.
Benefits to Growing Potatoes in a Bag or Bucket
The primary reason for growing potatoes in bags or buckets is to utilize space. Many vegetables don’t grow as well in containers so gardeners with small properties choose corn or pumpkins for their precious ground. Containers can be set on porches, blacktop driveways, or atop barren dirt.
Second, homesteaders settling into new properties often find their soil needs extensive amending before it can produce. By growing potatoes in a bag, they can till the ground and amend during the first year while still reaping a harvest from containers. A few bags of potting soil and some chopped straw feed the potatoes during the growing season. When the frost settles in, that material can be dumped out to contribute to amendment efforts.
Pest control is a third reason. By researching potato bug facts, you learn that the Colorado potato beetle burrows into the soil to pupate. Purchasing straw and potting soil eliminates the possibility of potato bug pupae within the dirt. Containers keep the potatoes up and out of infested dirt so you can use the ground for crops which are not in danger from the bugs.
Fourth is environmental control. By growing potatoes in a bag, you can plant early within a greenhouse then harden a mature plant off and transport outside. By starting or completing growth within the greenhouse you can harvest three to four crops per year from the same container. Growing in containers also allows you to control the amount of moisture. Potatoes don’t like too much water. If you’re cultivating during a rainy season, you can move the bags or buckets into a drier area.
The Right Container
Growing vegetables in pots don’t require spending an entire paycheck at a garden center. Though you can purchase attractive and expensive planters, growing potatoes in bags or recycled five-gallon buckets will work just as well.
First of all, let’s address a common urban myth. Pictures circulate around Facebook, showing pots with removable bottoms, allowing you to harvest “new” potatoes while allowing the plant to grow. Others claim you can cultivate one hundred pounds of potatoes within a single wooden tower. But those tutorials are either inaccurate or incomplete.
The photo with the two-part potato planter shows a duo of two-gallon-sized pots. One hand removes the inner pot while another plucks baby potatoes from the soil. This photo is inaccurate. It shows several young plants, perhaps two weeks old, above a pot bursting with new potatoes. Plants that young rarely produce new potatoes and the output isn’t that prolific. The pot could sustain one plant at the most. Also, potatoes prefer more than two gallons of soil.
Another tutorial instructs creating a box of upright beams and a square base. As potatoes grow, more 2×4 slats are attached to the beams to extend the box upward and more dirt is filled in. This works with how potatoes grow and the concept is sound. However, some tutorials don’t address what kind of soil to use, leading new gardeners to throw in barren clay from their yards. It also exaggerates the output. A successful plant within that box would produce fifteen to twenty pounds, but one hundred would be a rare miracle.
Though those pictures are misleading, you can still cultivate a satisfying harvest by growing potatoes in a bag or bucket.
The Bags: Choose bags with good ventilation. You can purchase cloth “grow bags” made specifically for potatoes, but they can top $45 apiece. Try woven feed sacks or old pillowcases instead. If you don’t have either and you might need to move your potatoes to different locations, purchase reusable shopping bags. But get the right ones. Some are made of toxic plastic that will leak chemicals into your potatoes. Look for “cloth” bags made from recycled milk jugs. The tag attached to the bag will tell you if the material is safe. Feed sacks won’t last more than a year but they’re free if you have livestock. Reusable shopping bags and pillowcases can last three to five years with the right care, for $1 to $5 each.
The Buckets: Pass by those flower pots and select the largest planters you can find. Each pot must hold at least four gallons of soil to allow potatoes to develop, and the more space you have the more potatoes you will get. You will need good drainage; if you purchase a container with a solid bottom, drill plenty of holes. Also, avoid dark-colored containers unless you’re growing in chilly weather. Potatoes grow best when the tops are warm and sitting in full sun but the roots stay cool within the ground.
To save money and keep plastic out of landfills at the same time, purchase five-gallon buckets from restaurants and delis then turn them into planters. Ensure the buckets have enough drainage by drilling small holes in the bottom. Do not set buckets directly onto grass or soft ground because that may clog the holes and impede drainage. Instead, set them on a pair of bricks or pieces of wood.
The Right Dirt
Never use soil from your garden, especially if it has any percentage of clay. The best material is potting soil, perhaps mixed with straw to cut costs. Clay compacts tightly and pulls away from the sides of the pot. It also doesn’t wick or retain water as well. Since potatoes don’t need a lot of fertilizer, potting soil can be purchased then used a couple years in a row as long as it’s composed of loose material.
If potatoes are grown in straw, they do need a bit of fertilizer within the bottom layer. Choose natural material such as compost or aged manure. Chemical fertilizers aren’t the best for potatoes because they contain high levels of nitrogen which will promote foliage growth but impede tuber development.
Planting and Growing Potatoes
Do not purchase potatoes from the grocery store unless they are organic. Most conventional potatoes have been sprayed with a chemical to inhibit sprouting. Also, grocery store potatoes can come from locations which may have viruses or fungus within the soil. For the best results, and to avoid adding diseases to your garden, find certified seed potatoes online or at a garden center. Avoid russets if you are growing potatoes in a bag or other containers because they require too much space. Instead, look for small varieties which set tubers close to the plant. Fingerlings are excellent for containers and taste better than any russets on the market.
Fill containers with up to six inches of soil. This should be the most fertile of all material used and can contain compost, rabbit manure, or aged manure from horses, chickens, or sheep.
Place three to five “eyes” within each container. A potato can have many eyes (the dimples in the skin) and each eye potentially produces one new plant. A six-eyed potato can start six new plants. Either place small, whole potatoes with only a few eyes within the soil or cut up a larger tuber so each piece has at least one eye. Three pieces is sufficient for a five-gallon bucket. Cover the potato pieces with another inch of soil and water lightly.
Sunlight isn’t necessary until leaves emerge, but warm, moist soil is. Do not allow the soil to remain wet because it will cause the potatoes to rot before they can sprout. Within two weeks, leaves will poke through and grow quickly. Place the containers in the sun, a greenhouse, or under strong plant lights.
When the foliage is at least six inches high, lightly pack soil and straw around the leaves and stems, leaving about one inch of foliage showing. Allow the potatoes to grow for another week or so until they are six inches high once again, then pack more material around the stems. Continue in this manner until soil or straw reaches the top of the bag or bucket. After that, let potatoes grow. Water only when necessary, remembering to keep the soil moist but never wet. Watch for signs of over-watering, such as stunted and curled foliage. If that happens, water less often.
Most potatoes form blossoms and some even form “fruit,” but some varieties never do. When blossoms form, or about a month before maturity, you can gently dig within the soil or straw to remove baby potatoes.
In 90 to 120 days, depending on variety, tops will turn yellow. The plant appears ill but it’s reaching the end of its life cycle. Once the tops have died back, carefully dump the soil into a wheelbarrow if you want to save it for next year or directly into the garden. Search through the material to remove potatoes. Throw away or burn plant tops, in case there is any chance they became infected with a virus or blight.
Brush soil from the potatoes but do not wash them until you are ready to use them. Potatoes that are washed may never fully dry, leading to rot. Leave potatoes in a warm, dry environment for a few days to “cure” them, then store in a cool, dark location.
What kind of harvest can you reap by growing potatoes in a bag or bucket? Honestly, a garden full of loamy and fertile soil is the best for any crop. But when that’s not possible, bags with good potting soil are the second best option. Five pounds per bag is attainable, and the materials can be reused the next year to lower the cost even more. Plus, you can grow better potatoes than what is available in stores. If you want to save space and avoid problems with bugs or bad soil, try growing potatoes in bags.
Originally published in 2016 and regularly vetted for accuracy.