Quite the clever method here folks! Today’s feature includes tips from a few different sources for growing potatoes vertically (in layers) instead of spread out in rows across your garden. If you have limited space or want to try some nifty harvest magic, this could be a great option for you.
It’s been over 10 years since I published this post and in this update (2023) I’d like to add a few tips and some notes to keep in mind:
- Potato varieties matter. The best results will be from late season varieties. See what kind grows best in your area and go from there.
- Early varieties will only fruit once.
- If you live in an area with scorching summers, the tubers will be affected.
- Choose a location in the yard that offers some shelter from the heat.
- The tower method does work, but achieving 100 lbs. as noted in the original source (which is no longer available), isn’t the typical result.
- If you have only a small space to work with or wanting a growing method that is fairly low maintenance (no digging up the garden, weeding, etc.), this is a good option.
Now onto the goodies…
First, there’s this article from The Seattle Times: It’s Not Idaho, But You Still Can Grow Potatoes:
The potatoes are planted inside the box, the first row of boards is installed and the dirt or mulch can now be added to cover the seed potatoes.
As the plant grows, more boards and dirt will be added.
- You plant in one bottom layer, boarding up the sides of each layer and adding dirt as you go higher (you wait until the plants have grown a bit before adding a new layer).
- While new potatoes are growing in the top layers, remove the boards from the first layer at the bottom to carefully dig out any that are ready for harvesting.
- Fill the dirt back in and board up the box again.
- You move up the layers and harvest as they are ready.
- I imagine the new potatoes in the first couple bottom layers would be somewhat awkward to get at but as you move higher–not so bad.
I traced the information provided in the article to Irish Eyes Garden Seeds, they also advise you can skip the box and try growing them in a barrel or wire cage instead.
He claims that most of his customers aren’t able to grow 100 pounds in the potato box, but he personally had success with 81 pounds one year and another customer did tap out at a whopping 124 pounds! (source: The Denver Post).
In another article on The Seattle Times, I came across a blog post from Sinfonian’s Square Foot Garden that details his attempt using this box method, he added this tip for a better yield:
Greg from Irish-Eyes Garden City Seeds let me know that Yukon Golds, and all early varieties set fruit once and do not do well in towers.
You only get potatoes in the bottom 6 inches, which is what I got. Late season alternatives to yukon gold are Yellow Fin and Binjte.
Bonus! For a handy project sheet, The Seattle Times has a nice image file detailing the steps (no longer available at source):
Imagine growing all those potatoes in a just a few square feet–and how drastically reduced the weeding job will be! So Clever.
Tips from another article (Potato Box Yields Scads Of Spuds):
- Select late-season varieties.
- Plant in multiple layers (adding a layer of potatoes, soil and side panels as the vines grow 12 inches above the soil. Don’t cover more than a third of the vine).
- Coil a soaker hose through each layer so the roots at the bottom of the box will get even moisture throughout the season.
- Plant in a loose soil, like mushroom compost mixed with potting soil.
- Don’t overfertilize (use a 5-10-10 fertilizer) and avoid Miracle Gro.
DIY Wood Pallet Bin
Reader Update: Here’s some info sent in by Christine who made a bin using wood pallets:
Last weekend, I was inspired by the Tip Nut potato bin – grow 100 lbs in 4 square feet. As nice as it looked, it seemed to be very complicated, especially unscrewing slats. Being a “just do it” kind of person, I asked my husband to build me one using pallets — which are free. He picked some up, but I realized that they were enormous, so he cut them in half and made side by side compost / potato growing bins.
The Tip Nut plan called for unscrewing the bottom portions to get the grown potatoes out. Rod attached pieces of wood to hold the front pallet in place and to allow you to slide it up like a window. I took books of hay to stuff in the openings of the potato bin so the dirt wouldn’t fall out. We’ll see how it does.
Here’s a photo:
Unfortunately we placed it up against our neighbor’s fence. On the other side is their dog, who our Puggle Feeney loves to visit. He is always trying to dig under the fence. With the bins in place over his digging spot, the poor guy jumped into the compost bin and got stuck!
Christine’s Update: After having it in place for a couple of weeks, I discovered that the local cats think it makes a fine litter box, so I’ve added a frame on the top with chicken wire to keep them out, but allow the sunlight and water in. See her page here for lots more info and tips: Food Security 2009.
Reed Screening Towers
Update: (Spring 2011)
Sunset.com: (web archive link since original page is no longer available)
Here’s another project using different materials but grown with the same basic idea. These are made with reed screening wrapped around tomato cages (to give them shape) and then secured to the ground with rebar stakes.
To get started, a single layer of seed potatoes are planted, a few inches of compost and rice straw is added and then as the vines grow taller, they are topped off with more rice straw for the tubers to grow in (no more soil is added).
At the end of the season, remove the bamboo screening and watch the potatoes tumble out!
Straw Towers
Update: (March, 2023)
This one’s from FineGardening.com: Ranging from 2 to 4 feet tall, these are comprised of 14-gauge wire fencing reinforced with a rebar post for extra stability.
Line with straw and compost in midspring, add a layer of potatoes, water thoroughly and repeat until the cage is full.
- Compost on the inside, straw on the outside…each layer should be about a foot deep.
- When growing in straw, watering well throughout the growing season is very important.
Once the plants die back in the Fall, kick the tower over and dig through the straw to harvest all the potatoes produced.
Comparison of Methods
Update: (March, 2023)
Mother Earth News: A great article comparing five different potato growing methods to see which provided the best results: Trench; Straw Mulch; Straw & Paper Mulch; Bags; Towers.
They found that along with the straw mulch & straw mulch over newspaper methods, the towers returned about 1/2 pound less per plant on average. Bags were the lowest yielding.
They also factored in time and labor as part of the investment cost. The towers were on the higher end (16:59 minutes per plant) due to the construction of the containers but they require the least weeding and can be used for a few years so the cost spreads out.
The highest yield from one of their participants was 3.38 pounds of potatoes per plant (in the tower method), and with that result, not even close to the 100 pounds we’re after.
so I could not figure out through out all the posts which potatoes are the best for tower growing?
anybody have a final verdict on WHICH potato is best?
Paul
Here in North Dakota we just plant the eyes of the potatoe with a little bit
of the flesh.
Where would all the dirt go if you actually got 100 pounds in that space?
Can anyone who has actually done a vertical potato garden with success say what variety of potato was used. Here is Florida most gardeners use an early season potato (Yukon Gold, LaSoda). I have read that these are definitely not good for vertical culture. Please, if you have actually have good success with vertical culture (either wire cages, boxes, or pallets), could you post which variety you used?
im growing potatoes in my flower box that i got off my potatoes t hat i bought from walmart that i for got abou tin the back of my pantry.. i have had no problems…. tires are safe. i get them from the junk yard and clean them off with saop and water and let them air dry for 2 days then use them. treated lumber is NOT good to use,my mother did this stuff all her life and we used wood off our property or that someoen was getting rid of that was from a tree they cut down a lil more werk but better for you! n:)
o0o n the garbage can thing… they have the cool ones with wheels that are very sturdy and you can roll them anywhere!! perfect for anyone and you can get alot of potatoes out of them!!
KENNY ASK;
IF YOU PLANT POTATO IN SOIL & COVER WITH STRAW AS IT GROWS WHEN & WITH WHAT DO
YOU FERTELIZE THE PLANT?
My husband and I tried to grow potatoes in the boxes like above. We put dirt over the plant every time it reached about 4″ and left 1″ showing, some of the smaller ones eventually got berried. It is about mid June and all of the potato plants died. We dug them all up and no potatoes at all. Can anyone tell us what happened?
what I have read indicates at least 8-12 inches above ground before adding mulch. One inch left exposed is not enough to support a healthy plant. You were only overzealous. Remember, the worst farmer is the one who doesnt try. Trying too hard is another issue. Youi just needed to let them grow a bit more, and cover a bit less. No more than a third of the plant being covered in a material addition seems to be a rule of thumb, as well as the 12″ tall (or more) before you cover that part.
I read the same thing. Let it get 12″ or so and then only cover 1/3 of the plant. Plants still need sunlight…..
Nobody has yet suggested that the potatoe must FIRST BE PLANTED PROPERLY IN SUFFICIENT SOIL! My first effort failed because the spud had NOT been planted properly.
TvI love this thread! One important point I haven’t read-
The reason the plants keep getting covered is to keep the
sun off the potatoes. If your potatoes turn green from the
Sun they are poisonous!
This is the second year I’ve tried this. I put grass clippings on. Both years, the plants were big, & doing beautifully. I had several levels of the wood added on. And both years, all of a sudden one day, the plants withered & died within a few hours. If I tugged on the withered plant, they would come easily unattached from beneath the grass, where it was slimy & smelled bad. I would love to figure out what I’m doing wrong before I try again.
If you were using uncomposted grass clippings, it’s possible that you reached the amount of clippings in the container that then began to compost themselves. They’d get hot enough to kill your potatoes. If they didn’t compost, then they’d start to rot, damping off the potato. Straw would be be better.
I agree with Kim. It sounds like they came off easily because the stem of the potato plant had rotted. Either too wet, which grass clippings really hold moisture, or possibly too hot as the clippings started to decompose. Ever reach into a pile of grass clippings and feel the heat, moisture and watch the steam rise up?
Try straw next time with just a few grass clippings maybe.
This happened to one of my potato plants in a black container. I overwatered it and then placed it where it was extremely sunny. It was smelly and rotten. Definitely the case of Bacterial Soft Rot.
i have been planting yukon gold and red pontiac in saw dust and planner shavings for years, i also have about 25 chickens and use planner shavings for bedding. in early spring i cover the garden with the chicken manure/sawdust, lay in the potatoes then cover with 6″ of planner chips,when the plants grow through i add more to about 2 ft. has always worked well
Car washes get their soap in plastic 55-gallon drums. The soap is usually completely non-toxic and washes out completely. Trying it this year for a fall crop with Russets in a drum. 🙂
My husband and I tried this method this year, growing the potatoes in wooden towers like this and building up as the plants grew. To compare, we also put in some with the traditional mounded dirt method of growing. The tower method simply did not work as “advertised.” We got potatoes at the lowest level of the tower, but nothing in any of the layers that we added as the plants grew. The traditional method of growing yielded a larger crop.
Use a 5 gallon bucket with the bottom cut out. Cut a vertical slit from the ridges down to the bottom. Put the bucket on a piece of plastic. Plant the first layer with six inches of soil. As the plant grows keep adding soil to cover about a third of the stem at a time. Let the plant grow to a foot over the soil when it gets to the top of the bucket. Depending on the variety the bottom will be about ready. The first harvest will give a good indication of how much time is needed for harvesting. The growth rate varies widely with the variety.
Pull up the bucket letting the soil slide down to expose some of the soil at the bottom layer. Tip the bucket and pick a few potatoes out to see how big they are. If the potatoes are not ready let them grow. Remove all but a thin layer of soil from the plastic and tip the bucket upright. Add enough compost to make up the soil that was consumed and add it back into the top of the bucket. Repeat the process until the potatoes are ready. When the potatoes are ready pick out as many potatoes as will be consumed. Just keep adding more compost to the excess soil each time.
Repeat the process as many times and as often as desired.
Note that the sides of the buckets are slightly tapered. Slitting the bucket makes it so the soil slides easily when you pick it up.
Leave the handle up so you won’t have trouble getting it in the center when it’s time to pick the bucket up.
This method allows for a continuous harvest without ever having to stop and start over, as long as there is sufficient light and water. Only as many potatoes desired need to be harvested at a time. Storage problems are eliminated.
Potatoes can be kept growing indoors in a window all year with enough artificial light to make about sixteen hours of combined natural and artificial light. The better the light the faster the yield but almost any light will do. The duration is what is important. For more yield use more buckets.
I can’t tell you how long the plants can be kept growing because they have more patience than me. I always end up either screwing up and neglecting them or starting over with new varieties.
We use a large trash can with the bottom cut out. Plant the seed potatoes…cover with soil and straw (Some times I use grass clippings) and as the potatoes grow tall- keep mulching it. At harvest time- you simply lift the trash can up & over so you can loosen everything to find the potatoes..usually they are very clean too!
We use to do this with old tires stacking one on top of the other. Great way to recycle old tires if you don’t have wood. Works well and much easier to harvest the potatoes.
Try hay. Put your starts on the SURFACE of the soil and pack the hay around the growing plants……the plants put out new stolons and potatoes into the hay……more hay, more potatoes…..just reach Into the hay anytime to harvest, and at the end of the year rototill it all into the soil. No digging, and your soil mulch is already in place. Enjoy.
Has anyone ever tried this using vinyl fencing? We have a huge problem with termites, and I have left over fencing that I thought might work.
What about just using plain old tomoato cages or a rolled piece of fencing held together with wires? Would that work? Just a thought. Maybe potatoes could still be easily harvest by reaching into the bottom as needed, you could still keep adding the layers as described. Just not sure it would hold enough moisture??? I had planned on using a barrel, now you guys have me thinking of all sorts of options. Maybe just use some 5 gallon buckets, without cutting out the bottoms, easy to dump out. Our local winery sets out boxes from all the grapes they use just for anyone, they are a lightweight wood, obviously must be OK for food, they held grapes, and they look moderatley nicer than tires to sit in the yard. I have a lot of hay and stray from used bedding from goats and rabbits, between the hay and straw and the animal droppings I have HIGH hopes of bountiful harvest!!!
That’s what I was thinking…why not use wire fencing. Just need to make sure the potatoes aren’t exposed to air or they will turn green. So using straw around the outside of the plants up against the inside of the wire will probably work well. Let me know how yours turns out?
I use my husbands old racing tires for my potatoes. These tires are wider and shorter than normal tires so they don’t take up much space. I start the potatos in the first tire, then add another tire and dirt as the plants grow. I also inherited his old tire holding rack so I put all the un-used tires on it for storage. This year I am using some of the tires to make mini raised beds in my larger garden. I have them spaced about a foot apart with metal stakes, in this area I plan on growing my tomatoes. Doing this will raise the soil temp for my sun loving veggies, keep out weeds, roots from other plants such as my strawberrys and help with moisture. You can’t really go wrong with tires unless you live in a hot climate, the northwest they work well.
If you have a sawmill nearby, you can get cedar lumber for a low cost. I know I can buy it here for 50 cents per board foot. This is an excellent idea for people who have a limited amount of space to grow a garden.
I have had great success with this method of potato growing. I use recycled black plastic pots (really big ones) that I buy at OSH for a buck a piece. Then, when the potatoes are ready, I get my daughter to tip the pots over and find the potatoes. She does it with her friends and they have so much fun counting the potatoes, lining them up from biggest to smallest, and, of course, eating them! A great project for kids and their grown-ups!
And as for variety, I like fingerlings and good old Yukon Gold!
I am using a tall Laundry hamper with landscaping fabric to block the soil from falling out! This way the holes in the sides still let the light in!
Hi all how about a complete organic way of growing potatoes …All you do is take straw lay it down one leaf at a time to make a row then set your seed taters on the leafs of straw then go back over them and cover with a leaf of straw or old hay even works….
Can you use old, rusty metal trash cans to plant in? Thanks
I am trying straw bale gardening this year. I have the 4 bales placed in a square with the middle open. Thought I may try potatoes in the center. Either fill with dirt/mulch or use a large pot.
I’m not sure if this question has already been asked but I just haven’t found the time to read every comment! LOL. Does anyone have a list of what potatoes are good for this I have heard that some kinds are not very good at growing in a system like this?
I made a potato tower this year for the first time. I used chicken-wire, straw and mulch. I made an 18 inch diameter circle, used 3 stakes to stabilize it. Then layered the mulch and straw planting 6 potatoes eyes facing the outside. I planted 30 potatoes and it looks like most of them have grown. Not a very pretty thing but I cannot wait to have my own potatoes to eat.
I am doing this for the first time this year, we used russet burbanks, shepody’s and red pontiacs. All are doing pretty well, the shepody’s seem to really be taking off tho! I simply took a piece of wire fencing and made a large circle with it. Nothing too fancy. I also tried just piling straw on bare ground, tho it’s much harder to keep the straw in place (esp with the neighbor’s chicken’s continuing to fly over my fence and dig under the straw for bugs!)
I tried this technique for the first time this year, and I am not finding any potatoes. Why? I did everything that I was told to do, but o potatoes. Please help. The plants are done flowering and starting to wilt.
I like Mandy tried this for the first time and got 0 potatoes. Some on the ground but none up the stem, I just dug them today. What did I do wrong?
very excited to try this . extremely disappointed in the end results. enjoyed doing this all summer .watching the plants grow , no potatoes. very disappointed. What the heck happened?
I have nine stacks of tires with soil in only the top tire. I put a barrel lid in the top one. Growing seventeen different vegetables. All are doing great. I’ll take my chances on possible toxins in the tires compared to what may be in the food we get at the grocery store. Evidence shows some foods have many toxins from herbicides, pesticides, insecticides, etc. in them. Do you hear of anybody having trouble from food grown in tires?
I’m new to gardening and really like this idea! Could you tell me please, how long does it take for a “layer” to be ready?
I just started using gardenboxes last year and had overall good results. I’m excited about trying this method of growing potatoes. My question is can the same method be applied to sweet potatoes?
I built 4- 4 by 4 boxes 8 in” high .Used 1+8 hemlock boards untreated on leges and braces at waist high,Lined them with black garbage bags.They last longer than the clear.put drainege holes in the bottom.Filled with peat moss and vermiculite.compost Blood meal.mulched them with chopped leaves. Got about a bushel of potatoes out of the 4 boxes.I could dig them out with my hands.Just right for an 87 year old man.
Going to try the above method next year .Besides my way.
Has anyone had experience using pine straw/gathered pine needles instead of straw or hay?
Thanks for any input!
Some years ago, a radio call-in show horticulturalist advised putting old pine needles into the same hole with the seed potatoes when planting, to keep various plant fungi away. Worked pretty well for me, and helped adjust soil to increase acidity where I needed it. Would not advise using only pine needles. Also from my experience, although hay worked as well as straw for me in covering potatoes instead of hilling with soil as they grew, next year did I have weeds ! Grain straw a better option if you have a good, free, supply. Potatoes are not then as affected by soil borne diseases.
We have used old tires the same way, and the plants grow, add another tire. Be sure to only water once when planted then wait. They can very easily rot with too much water. I give them a good drink then wait to see several leaves before another drink.
I have yet to see any method grow 100 lbs of potatoes yet. I have watched numerous youtube video’s and either they didn’t post an update or didn’t have luck higher than the first board or two. I did a 55 gallon barrel and that didn’t gain 100 lbs. I hope if someone gets it to work they post a video so we can all see it. Most pressure treated lumber now a days are much safer than then the old method.
Have tried this in multiple bins and had good results in most, this is what I have learned so far.
Variety used makes all the difference with most maincrop varieties being the favored seeds to use for vertical growing because of their longer growing period.
Using waste spuds or peelings from the kitchen will give a crop but unless you know what variety they are results will be unpredictable often only limited to bottom of bin.
Watering regular & evenly without water-logging is a major part of producing good results and high potash fertilizer will help too (Comfrey leaves can be added to the soil/mulch without the need to compost them first but that’s a whole new subject =)
if bin was started early enough try using earlies and maincrop at start then add a few more earlies part way up the bin near the sides but not too late in the season as they wont have time to develop fully
I wonder if this method would eliminate mice/voles (voles are like mice only slightly larger with short tails) getting into the potatoes. Two years ago, I ended up with very few undamaged potatoes (red and russet varieties) because the rodents had dug up under the rows and had eaten the potatoes during the growing season. Many of the potatoes were completely hollowed out! We went to dig the potatoes in the fall and from two 75′ rows we were only able to salvage probably 20 pounds of potatoes when we normally would have had 200 pounds or more. During the summer, I didn’t notice any holes in the soil but once the plants died down some, the holes were visible. In 35 years of gardening here in Idaho, I have never once had a problem like this with potatoes! I didn’t bother planting potatoes last year being afraid of a repeat of the previous year. We did have this happen to some carrots one year that we left to winter over in the ground. When we dug them in the spring, we discovered mice literally living inside of hollowed out carrots. The barnyard cats and our dogs had a great time chasing mice as we dug the carrots and stirred them up from their little carrot nests!
Does this work for sweet potatoes?
No. will not work for sweet potatoes. White potatoes set potatoes on the stems as they are covered with dirt. Sweet potatoes set sweet potatoes on the roots as they grow down into the ground. That is why traditionally, you plant white potatoes in a trench and fill in around the plants as they grow. You plant sweet potatoes in the top of a hill or long mound and they make babies on the roots as they grow downward; then you dig them up in the fall.
Will this work for carrots or long radishes
Any suggestions on keeping field mice out of the garden. Last year they destroyed my potatoes, watermelons and cantelopes. I am afraid to put out poison because I don’t know if their droppings will be toxic.
My husband and I tried growing potatoes in 3 layers of tires last year with poor results. We started with 5 potatoes in the bottom tire, covered with soil. When the plants were about 8 inches high, added another tire and more soil. Another tire was added when the plants were 8 inches above the second tire. Then we watered and fertilized; there was an abundance of foliage so we were looking forward to a large crop of potatoes. Unfortunately we got no more potatoes from the 5 than we would have from planting one potato. I would like to try it again, but trying to figure out what we did wrong. Any ideas? Oh, we planted Yukon gold potatoes which usually do well in our area.
Works great on all potatoes not named Yukon Gold … in my opinion anyway … I do better with the Yukon Gold’s in a bed
So, I’ve read all the comments and have done some research on the potatoes themselves. I hope this will answer a lot of peoples questions. Traditionally potatoes are grown in 12″ deep trenches buried in about 4″ of COMPOST and then as the potatoes grow the soil is mounded up around the vines for another 6-12″. If using actual potatoes place the cut side down and the eye side up facing toward the sky. Potatoes need good compost at the roots not along the vine portion of the plant to produce big healthy potatoes. The potatoes grow laterally (out to the sides) not downward into the soil so much like carrots would. In a trench the potatoes would be spaced 18″ apart to allow room for the potatoes to grow BETWEEN the vines. So if you grow on the ground without a box, tire, fence round etc. you will only need to dig down as deep as your trenches would have been to begin with in order to harvest them. The benefit of the containers (whatever it is you decide to use) is that the lateral distance they can spread out is limited by the container. Some potatoes can spread as much as 40″ laterally so a narrow container would probably not give much of a yield. Most potatoes only grow to 18″-24″ tall (the vines). So a deep container is not needed either. Really two feet deep is more than deep enough. You will only want to add soil (traditional planting material) until the vine begins to flower (feel free to experiment with straw, hay, grass, leaves etc. they are your potatoes!). Water well during the flowering period as this is the point at which your potatoes will begin to form. Potatoes have a set period of time that it takes to reach maturity (check your product growing periods when ordering) depending on species. Short season potatoes take from 59-85 days USUALLY. Long season growth potatoes can range from 85-110 days or so. You can sometimes get 2-3 successions of plantings in with proper planning and potato species choices. Potatoes are not ready to harvest until 2-3 weeks AFTER the leafy growth has died back. This means that early harvest of the bottom portion of the potatoes is not going to really happen so there is not really any need to tip your containers or dig around in the soil etc. until it is actually harvest time. Once the vines have died back you need to wait the 2-3 additional weeks for the tubers to complete their growth cycle. They will continue to grow for that long without need of the vine on the top. This period of waiting time is also necessary so the skins of the potatoes can firm up and toughen a bit, if you will, to get them ready for long term storage. Most species will store well in any cool, dark, dry area. A cellar, a dark cool closet, an old freezer buried in the back yard (do a Google search for directions on this) etc. Most “seed” potatoes are not sold as potatoes, they are sold as tubers so the name is a little misleading. Old potatoes that are sprouting can be used but as mentioned before, some of the potatoes from the store are treated so they don’t sprout for quite sometime. Do some research to find the best potatoes for your own area by looking at nurseries that are in a climate similar to your own area, check the growing time, the height of the vines and the spread of the lateral potato growth to find the type of potatoes that will grow best in the containers you want to use, whatever type they may be. For myself…I like to use fencing rounds and line the outer edges with straw as the vines grow, using a good compost filled garden soil so the soil stays nice and soft and holds just enough water without rotting the potatoes. It takes most new gardeners a few years to get all the kinks worked out so don’t give up after trying only one year. Good luck to all of you!
Thanks, Rose L, for passing on your experiences. This year will be my third at attempting potato growing and I’ve learned so much each year.
the last 2 years I have used milk crates. I cut the bottom out of several and lined them with mesh to keep the dirt in. As the potatoes grew I just add another bottomless milk crate and more dirt. At the end of the season I just had to start removing milk crates and collect the bounty. You can go as high as you want. Hope this helps someone. Happy Gardening
Hi Rose I haven’t read all the posts so if I’m repeating something already said, sorry about that. I agree with most of what Rose says except that I have used a variation of this method and it works fantastic. Where I disagree with Rose is the 40″ lateral growth meaning that a confined container will necessarily cut down your yield. If the tuber encounters a barrier, it doesn’t just stop there. It will turn and grow in whatever direction it can, so it will use up more of the volume available to it. I have seen potatoes grown in trenches and this method and in the containers you get many more per square inch of soil.Also yes the plant only grows 18 to 24 inches tall above ground level so if you have a container that is 3 feet tall, that is filled layer by layer, the plant will grow 18 to 24 inches beyond that three foot height of the soil and the three foot high container will be full of potatoes. As the plant grows and you keep covering up the new branches with soil, those branches now become tubers that will produce potatoes. As I said,I use a variation of this method but I use large garbage cans, or rather plastic garbage containers with holes punched in the bottom for drainage. I love these containers for this use because they have a lip at the top of the container, which makes it almost impossible for potato beetles to get in, thereby making the use of pesticides totally unnecessary. 🙂 If you try garbage containers, make sure that you get one with a lip that turns out and down.
Would this work with sweet potatoes as well?
When I was a kid, we did this in my agriculture class using tires. I do not remember which varieties we grew. With the tires, there is no harvesting the bottom layers early but I do not remember that being an issue. As the plants would grow, we would simply stack another tire and add more soil. Once we had it up about 3 feet we kicked the tires over and harvested