to educate, inspire and equip the urban homesteader

Growing potatoes vertically

July 9, 2010

Row of potatoes

Urban gardeners have plenty of things to worry about, not the least of which are pests, sunlight, soil and access to supplies.  There’s one complaint that trumps them all, though, and that’s space.  Unlike our rural counterparts we can never seem to find enough space for all the things we’d love to grow and eat.

Over the past couple of years, I’ve spent plenty of time thinking about the space problem and trying to find ways around it.  I’ve grown pumpkins up the side of an unknowing neighbor’s house, I’ve cut the bottoms out of 2-gallon containers and stacked them on top of each other (3 high) to grow asparagus in a container that could travel from apartment to apartment with me, I’ve packed fire escape stairs with planters (not recommended by the Fire Dept) and so on.  However, one of my most clever uses of space has got to be the potato bag.

Potatoes need long, stems in order to produce an abundant crop.  The longer the stems are allowed to grow, the larger your crop.  On farms, potatoes are grown in great hills which get piled higher as the season progresses.  My grandmother put tubers in the ground and piled straw on top as they grew until she had what I imagine must have been enormous mounds of straw with potatoes hidden underneath.  The trouble with hills is that the base is always wider than the top, taking up much more space than an average urban gardener can sacrifice for the joy of digging up your own potatoes.

I’d read all kinds of solutions to this issue – Pam Pierce of Golden Gate Gardening suggested constructing a tower made of chicken wire and planting the potatoes up in layers with straw to allow the stems to grow out the sides.  I’ll probably still try this idea some day, but in the meantime I needed a quick, tidy fix that didn’t require wire cutters.

As with most problems, the solution came to me over a cup of coffee.  I was sitting in my local coffeeshop (which, if you’re ever in San Leandro, you should stop by!  Zocalo is the best!) sipping on a fresh coffee and watching the staff roast beans.  I happened to notice that they had mountains of burlap coffee bags that the fresh beans come in.  A quick inquiry later and I had a deal for trading some of my hypothetical potato bounty for some used bags.  When they don’t give them to me, they donate the bags for school potato sack races, so I’ve been careful not to take more than I need!

Potatoes just starting to poke out of the soil

Here’s how it works:

  1. Roll down the sides of a tall bag like burlap coffee bag or used feed bag until it’s only about 12 inches high.
  2. Choose your location carefully.  You want full sun and preferably soil under the bag.  Because the bottom of the bag will eventually rot out, you want to make sure to place it where it will stay until harvest.
  3. Add six to eight inches of soil into the bottom of the bag and bury the seed tubers in soil, making sure they’re completely covered.
  4. Water every few days, making sure the soil stays moist but not wet.
  5. After a couple of weeks, the green stems will start to peek out of the soil.  Once they’re about six inches high, add more soil and/or compost, leaves, etc to cover all but the top set of leaves.  The stems will continue to grow.
  6. As the soil line gets higher, unroll the bag to match it.
  7. Continue adding soil and mulch up to about two feet, then add whatever you have on hand to hold the bag up.  Straw and dead leaves work well, as do pine needles.

These potatoes are about a month old

For new (small) potatoes harvest two weeks after flowering.  For larger potatoes, harvest two weeks after the entire plant dies off.  By now, the bottom will probably be rotted out of your bag and you can just tip it over and harvest the little tubers from teh bottom of the bag!  Inside the bag you’ll find more redworms (and possibly slug) than you ever thought possible as well as some beautiful soil full of black gold (aka worm poo).  Because rotation is always a good idea, I use that soil and straw to plant my tomatoes in and mulch my tomato patch.  Your tomatoes will thank you for this little big of urban compost.

In the Bay Area, you can plant potatoes from February to August and it’s a good idea to succession plant your potatoes every 4-6 weeks, allowing you to harvest almost year round.  This year I tried pushing my luck and planting some potatoes in January and they grew, but they stayed quite tiny and there weren’t very many of them.  I don’t recommend trying it!

Also, be sure to only plant seed potatoes that were grown for the purpose of planting.  Your run-of-the-mill grocery store potatoes may harbor diseases that can enter your soil.

This is a great solution if you're working on a rooftop garden because the bottom won't rot

There’s still time left to plant some potatoes so get off your tush and get yours in the garden, on the patio, roof or fire escape today!  (email me if you have trouble finding seed potatoes – this is a  tough time of year to find them, but I have a few left –

Happy planting!


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  • Is that what those things were. I thought they were just fertilizer bags.

  • Fertilizer bags? You should know me better than that. Sounds like you need a tour of my compost piles. ;-)

  • oooh – I’ve wanted to try this – thanks for posting. I bought a burlap tree-frost-protector and planned on trying it next year.

    • So many great uses for burlap on the homestead. I’ve used them as weed block once they’ve broken down and can no longer hold potatoes. The weeds will eventually begin to grow through so you just flip the burlap over and use the other side.

  • I live in Massachusetts. When should I plant my potatoes?

    • Hi! The traditional time to plant potatoes in most of the US is St. Patrick’s Day but I’m sure they could start going in now. You might check with your local extension office to be certain about the planting time for your area just to be safe. Someone local always knows best!

  • Nice website! Do you think it would help to stimulate more potato growth above the initial soil level if you snap off a few leaf stems here and there on the main stalk, in order to help the plant send out rhizomes/roots and thus increase potato yield? That is, snap off the leaf stems just prior to burying each 6″ layer with more compost/leaves/straw?
    Or, would that jeopardize the plant with disease?
    Thank you!

    • Great question Mary and I have to admit I don’t know the answer. My initial thought is that it could weaken the plant because those tubers are gaining their energy from the potato leaves that have made it above the soil line and are photosynthesizing. I’m certainly no potato expert though. Anyone else have an answer to this?

  • Well, in the absence of a definitive answer I am trying a little experiment: I have a half dozen potato plants with foliage of about 1 foot high in a container that I will gradually build up and fill in as they grow. I’ve broken off the branches of 3 of the plants, and 3 I’ve left alone (same variety, same start dates, same soil, etc.) I’ll see which method yields a more abundant crop and report back in a few months.

    Thanks, appreciate the help,

  • Well OK, I’m on the edge of my chair, what was the answer? Does cutting back the foliage produce more or fewer ‘taters?

  • you can use old tires, cardboard boxes and many other discarded items to build your vertical potato mound, I cam currently using landscaping fabric and stakes because I have a surplus of these materials this year.

  • can groundnuts,and ginger be grown using the same way?

  • I like this .fARMCURIOUS

  • Growing potatoes in a bag is on my list this season and thanks for the great information. We used one of your photos in our recent blog and credited your website. Thanks so much.

  • Hi, I would like to know how to add dirt to grow, how much plant do you leave at the top while adding dirt or straw? I used straw after 2 ft of dirt and it didn’t seam to work very well, we have wood that’s 4×4 and 4 ft tall by adding slats as it grows, going to try again this year, any help and thank you!

  • Mounding and mounding store bought soil or compost made for the most expensive potatoes ever last year. Can I start them in soil and then continue to mulch with straw to get the long stems?

  • Information is wonderful. What is that plastic bag and when do you get it from I planted regular sprouts from a store-bought potato which I sprouted in the refrigerator will that make diseases in the straw. Sharing is a wonderful thing. I love it. Thank you.

  • What is the bag you have. What came in it? I did not get your answer yet. Your sharing is appreciated. Thank you.

  • sorry I’m anxious to know

    • The plastic bag had chicken feed in it. We had it because we buy bulk feed for our chickens but I’ll bet you could check into a feed store and ask if they have some extra bags. It’s not recommended to plant potatoes from the grocery store in the ground since they could carry diseases – I don’t see why you couldn’t plant it in a bag though as long as you don’t add the straw and soil to your garden later. (Please note that blog comments posted before 6am our time won’t receive an immediate answer – if you ever have an urgent, urgent question, email might be best.) ;-)