Can you grow potatoes in your garden by planting grocery-store potatoes? If you search the internet, you’ll find every possible answer to this simple question.
The correct answer is: It depends. But not in some wish-washy, random, some-do, some-don’t, luck-of-the-draw kind of way.
It depends on whether or not those grocery-store potatoes were treated with the sprout inhibitor chlorpropham. That substance keeps potatoes from sprouting by permanently damaging their ability to grow. And it is commonly used in the U.S., for potatoes sold at the grocery store.
Key fact: Potatoes labeled as “organic” cannot legally be treated with chlorpropham.
So, if you want to buy potatoes from the grocery store and plant them, buy potatoes labeled as organic. In five years of doing that, I’ve never had that fail.
By contrast, planting non-organic potatoes from the grocery store may or may not work. It depends on whether or not they were sprayed with chlorpropham before being shipped off to the grocery store. And there’s no way to tell, just by looking at them.
Separately, there’s more to this issue, because, unlike “seed potatoes”, grocery-store potatoes are not certified as “virus free”. But I think that’s more of an issue for commercial growers than it is for the casual home gardener.
Details follow.
The damnable thing about reality is that it keeps changing. Just when you think you have some tiny part of it figured out, somebody upsets the apple cart potato bin.
I’m not talking about the pseudo-culture-wars around the rebranding of the Potatoheads.
And I’m not referring to the consequences of the Federal Web Designer Full Employment Act. This is the 1997 Federal statute requiring that every commercial and governmental website must make significant changes in layout and functionality, any time more than half of its users have figured out how to use it.
Nope, today’s rant is about spuds at Home Depot. Bags of certified seed potatoes, for spring planting, prominently displayed for sale. These were offered with several other items I’d never seen there before, including onion sets and, of all things, pomegranate seedlings. (Apparently, hardy to USDA Zone 7 as figs are — with the occasional die-back in a hard winter.)
I don’t recall ever having seen seed potatoes at my local Home Depot, and I’m not quite sure what that implies.
Why are those potatoes there, now?
I know why I grow potatoes. I tried it in 2020, and I liked the results. I grow a modest amount of potatoes because:
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- They’re easy to grow.
- Deer won’t eat them (so far).
- They taste better than store-bought.
- You get a lot of edible calories per square foot of garden.
- They store well.
I figured that almost nobody in my area (northern Virginia) grew potatoes in their back yard. For one thing, our heavy clay soil is far from ideal. If you decide to get around that issue by going the “no-dig” route, your home-grown potatoes will end up costing more than store-bought (see Post #1073).
And it’s not as if the potato is some beautiful addition to the garden landscape. It’s a scruffy green plant with nondescript flowers. Not only are you supposed to clip the flowers off, you have to spend weeks looking at the dying foliage before you can dig up the crop.
And so, as of last year, this tiny part of my world made sense. Potatoes are cheap to purchase, expensive to grow in our ill-suited soil, and not much to look at in any case. And I couldn’t find seed potatoes locally. It was all completely reasonable.
You don’t see snowmobile dealerships in Florida. You don’t see masses of seed potatoes for sale in a Home Depot in the Virginia suburbs of Washington DC.
But now, my local Home Depot is offering several different varieties of pre-chitted seed potatoes.
Those don’t appear anywhere on their website. The only way to know that my local store has them it is to walk into the store and — surprise — they have enough bags of seed potatoes for hundreds of local gardeners to be growing potatoes this year. What I’m saying is, it’s not like they decided to test the waters with a few packages tucked away on a shelf somewhere. They have cardboard bins full of 1-pound bags of seed potatoes.
And they aren’t even cutesy, exotic spuds, the kind you’d market to the upscale gardeners in this area. Home Depot is offering your basic red, white, and gold potatoes, just as you’d buy in the grocery store.
And so my world view is turned upside down. Is this some new fad that has somehow passed me by? Has there been some viral potato-based meme? Is Yukon Gold the new black? Has some post-pandemic survivalist instinct kicked in? Or has there always been some quiet, underground population of potato fans in this area, and has Home Depot has finally decided to crack the lucrative home-potato market?
Change is bad. Inexplicable change is worse. What’s the take-home message when Home Depot is offering the seed stock for what amounts to cheap survival food, front-and-center in a mid-aisle display?
Can you grow potatoes bought at the grocery store? Answer: Buy organic potatoes.
Please note, I’m not saying “should you”. I’m answering the more basic question “can you”. Internet advice is all over the map. Some people swear it doesn’t work at all. Some people swear it works fine.
The real answer is, it boils down to the type of sprout-inhibiting treatment that was applied to those potatoes. And, as far as I can tell, the treatment that permanently prevents the potato from growing is not legal for use in potatoes labeled as “organic”.
So, yeah, in theory, you can use organic grocery store potatoes, with a pretty good chance they’ll grow just fine. You still risk importing potato viruses into your garden if you grow grocery-store potatoes. But advice that you literally can’t grow potatoes from grocery-store potatoes does not apply to to the sprout-inhibiting treatments legal for use on organic potatoes.
Detail follows.
If you grow potatoes, in theory, you’re supposed to use “seed potatoes”. The first time I tried potatoes, that’s what I did. I bought some on-line from a seemingly reputable dealer. It was an expensive failure. None of my super-duper seed potatoes sprouted. Given the cost (and the cost of shipping), I’m sure I’d have bought them locally if I could have found them.
Ever since that first flop, I’ve gone against standard advice, and simply bought eating potatoes locally and planted them.
That’s risky because you might introduce some long-lived potato diseases into your garden soil that way. For this reason, potatoes sold as seed potatoes must be certified as being more-or-less virus free, and commercial potato producers in most (possibly all) areas are required to plant nothing but certified seed potatoes (or something close to that, or deemed equivalent to that).
There is some internet chatter suggesting that it’s illegal for a home gardener to plant store-bought potatoes in (e.g.) Idaho. But if you actually read the statute, that doesn’t appear to be the case. In Idaho, it’s illegal to sell potatoes for planting that are not certified as disease-free seed potatoes. (For what it’s worth, that’s also what the law of the Commonwealth of Virginia says. And, I’d wager, that’s what the laws in every state say (e.g., Florida).) But in addition, in it’s illegal for commercial growers in Idaho to plant anything that is more than one generation removed from certified seed potatoes. But nothing in Idaho statute (or at least, that part of the statute) addresses home gardens.
But if you’re just a casual potato grower, probably the bigger risk is that your grocery-store potatoes may not grow. By the time you get to late winter/early spring, it’s a good bet that almost all eating potatoes you can buy from almost any source have been treated with some type of sprout inhibitor or “anti-spudding agent”. (Because, if not, given how they have to be stored so that they remain pleasingly edible, they’ll have started to sprout by that time, if not treated.)
In the U.S., commercial, non-organic food potatoes are most commonly treated with chlorpropham (reference). This is basically a powerful herbicide, and there’s enough concern over toxicity that the EU and Great Britain banned its use starting in 2019 (reference). It works by permanently damaging the ability of potato cells to reproduce. Even contamination with low levels of it greatly impacts subsequent growth of the potato plant (reference). And I noted that the concentration of Chlorpropham used in that last study was well below the 30 PPM limit on residues on food potatoes for sale in the U.S (reference, U. Idaho extension service.)
If you read about someone trying and failing to grow potatoes or getting a terrible yield, using food potatoes, or you’ve seen advice not to use store-bought potatoes, you’re probably reading about the effects of chlorpropham. If that’s been applied, there’s no way to reverse the effects. It fundamentally and permanently alters the ability of that potato to grow. (And, see above, it even stunts any successive generations of crops grown from those potatoes, if you can get them to grow in the first place).
Now we come to the $100 question: Can chlorpropham (CIPC) legally be used on U.S. potatoes marketed as organic potatoes? This University of Idaho publication pretty clearly says no, it cannot:
Alternatives to CIPC are needed for both organic and export markets—where CIPC is not permitted.
(But if you really want to be sure, you have to consult the USDA National List. If it’s a synthetic compound, and it’s not on the list, it’s not allowable for use in produce labeled organic. And, to be clear, it’s not on the list. So, not allowable for use in production of potatoes labeled as organic.)
Organic methods of potato sprout inhibition have turned to using substances that are Generally Recognized as Safe (GRAS), or that are themselves natural compounds, or that are on the USDA National List. The sprouting of potatoes stored under normal conditions can be inhibited with ethylene gas, or by application of concentrate essential oils such as clove or mint oil, or by use of hydrogen peroxide (reference, reference). You can also keep sprouting down by judicious choice of potato variety, or choice of varieties that can be stored at colder temperatures without loss of flavor/conversion of starches to sugars.
Here’s the key point: Most organic methods of sprout suppression do not permanently damage the potato. They will kill off the sprouts that are active. Some temporarily inhibit new sprouting. But they don’t prevent further sprouting, once they are stopped. In fact, one of the main drawbacks of these organic methods is that they have to be re-applied if the potatoes remain in storage. Here’s the key paragraph, from the University of Idaho publication cited above, emphasis mine:
These alternative compounds are not true “sprout inhibitors” that inhibit sprouting by interfering with cell division or some other biological process. Volatile oils and hydrogen peroxide are more correctly called sprout suppressants, as they physically damage developing sprouts with a high concentration of the product in the surrounding headspace in the potato storage. Because of high volatility, these compounds leave behind little or no residue. Since new sprouts continue to develop, repeat applications are required at two to three week intervals or on a continuous basis.
Source: Organic and Alternative Methods for Potato Sprout Control in Storage, by Mary Jo Frazier, Nora Olsen, and Gale Kleinkopf, University of Idaho, September 2004.
Courtesy of the same University of Idaho group, you can see what a potato treated with clove oil looks like. The clove oil kills off the existing baby sprouts, leaving little black dead sprouts all over the potato. But this will not prevent the potato from re-sprouting.
Source: Potato Sprout Suppression from Clove Oil, By Nora Olsen, Mary Jo Frazier and Gale Kleinkopf
Based on the many, many bags of grocery store potatoes I looked at this spring, that picture looks awfully familiar. I’m not sure whether you truly can tell whether a potato has or has not been treated with a commercial essential-oil sprout suppressant. But I’ve noticed a lot of these little black dead sprouts on the organic potatoes at the supermarket. And I’m guessing that what I’m seeing is potatoes that have been treated with these sprout suppressants, and not chlorpropham.
For my first-ever crop of potatoes, I got mine at my nearest farmers’ market, after my boxes of seed potatoes failed to grow. That worked great. Since then, I tend to cruise the bags of organic potatoes at by local grocery stores, looking for ones that are showing the very first signs of sprouting. My experience is that if you can see those tiny little white (not black) sprouts forming, they’ll grow OK. They are already in the process of recovering from whatever organic sprout suppression treatment was applied. And getting them at the grocery store is both cheap and convenient.
In any case, potatoes are a crop where you have to get started early. By the time I saw I could buy seed potatoes at Home Depot, it was too late for this year. You’re supposed to “chit” the potatoes before you plant them, that is, get them to break dormancy and start sprouting. That chitting process takes a month or two. If you want to plant your spuds on the traditional date of Saint Patrick’s day, you have to buy them and set them to chit sometime around the end of January. So I already had a couple of trays of sprouting potatoes in my kitchen by the time I saw the commercially-available product at the Home Depot.
Finally, I repeat, you can grow them this way. Whether the casual gardener should do that is an open question. This does not address the issue of potential spread of viruses harmful to the potato. I’m not sure how common those are in food potatoes, but for sure, they are common enough that every state that I’ve looked at has standards that seed potatoes must meet. Further, if you introduce a particularly harmful virus into your garden soil, my understanding is that it effectively ruins the soil for potato production for years.
And, when you get right down to it, it’s not like there’s a huge cost savings, once you get your local big-box stores selling seed potatoes. Home Depot has certified seed potatoes $4 a pound. If the only trusted alternative is organic potatoes at the supermarket, you’re probably going to pay $2 a pound anyway. Had I known that Home Depot was going to be marketing these this year, I’m not so sure I’d have been buying and chitting organic grocery store spuds.
But, for now, it is what it is. I had one complete flop using certified seed potatoes, and excellent success (so far) using farmers’ market and organic grocery store potatoes. For now, I continue to grow mine from food potatoes. I’m not sure that it’s smart, but so far, it works. And that may change, now that my local big box has them ready-to-plant, right off the shelf.
Anyway, if you go the grocery store route, pick up a few bags, to spread your risks. Leave them out to chit. I figure, if they start putting out sprouts sitting in my kitchen, they’ll probably do just fine when I plant them in the garden. If they don’t, eat them.
