Planting potatoes typically means rows lined with seed potatoes buried under the dirt. It’s a well-established planting method, but it’s one with challenges including needing a lot of space and the threat of disease and pests.
Planting potatoes above the ground in a tower can help solve some of those challenges.
Potato towers are tall planters that let you grow your potatoes above ground. Instead of rows, potatoes are planted in layers on top of each other.
They are fairly simple to construct. All you need are a few tools and materials.
Building a potato tower
Building a potato tower requires a section of three to four foot high wire fencing sturdy enough to support the tower, heavy wire, a strong metal or wood post to anchor the tower, straw, a shovel, wire cutters, compost and seed potatoes.
Make a cylindrical bin using the wire fencing. It should be about one to two feet in diameter and use the heavy wire to fasten the ends together. Pound the post or pole into the ground and wire the bin to it so it won’t fall over if the potatoes start to weigh it down.
Put down a layer of straw around 3-inches deep in the bottom of the bin and spread it out and up about a foot on the sides of the bin so there is a hole in the middle of the straw. Fill that hole with compost.
Next put your seed potatoes in a circle along the outside edge of the compost next to the straw every six inches or so. Cover them with a thin layer of compost and give them a good watering.
Keep adding straw-compost-potato layers until it is about 4-inches from the top of the bin. Ideally, each layer should be about a foot thick. For the final layer, cover it with five inches of compost and a final few handfuls of straw.
Potatoes like towers
As a crop, potatoes are especially well suited to grow in vertical towers.
“The way potatoes [normally] grow is the stems grow above the ground, but the potato itself grows underground,” said Caleb Goossen, crop and conservation specialist with the Maine Organic Farmers and Gardeners Association. “Most varieties of potatoes grow at or above the level of the seed potato.”
It’s the same for potatoes planted in a tower. The new potatoes are going to grow above the circles of seed potatoes and they have nowhere to go but up. If you have covered each layer of seeds with a thick layer of compost and straw, they are going to have plenty of space to form and grow.
“If you provide good fertility in the [growing] mix and make sure it has adequate water, you can provide an ideal growing environment,” Goossen said. “That will boost your yield a bit.”
Avoiding disease and pests
It also gets the entire plant above the ground and away from the moisture and organisms in the soil below that can cause foliage diseases on the plant’s leaves, according to Goossen.
It can also help control one of the state’s biggest potato pests — the Colorado potato beetle.
“The beetles typically over winter in the [ground],” Goossen said. “If you have constructed a tower above that [ground] you can avoid some [beetles and] if you do end up with them on your tower, you are more likely to see them and you can pick them off.”
Any beetles that manage to evade capture and are still on the tower at the end of the season can easily be dealt with. Goossen said you can pull the tower up and dispose of the whole thing to get rid of the bugs.
One way to do that, he said, is putting it in good compost that will be hot enough to kill the beetles.
Still time for a tower
Planting by going up instead of out is a good option for anyone with limited garden space, Goossen said.
“It would be hard to grow many plants using just towers because it would take a lot of time and labor,” he said. “That’s why they work well for small spaces or container gardening.”
And it’s not too late to set a tower up for this season, Goosssen said. But don’t wait too much longer.
Keep your tower watered all summer — something that’s been easy to do this year, Goossen noted.
“This year growing potatoes above ground is allowing all excess water to drain out,” he said. “That’s really beneficial if you have heavy soil that does not allow good draining.”
Harvest
It’s time to harvest your potatoes when the leaves of the top layer have died back in late summer. And harvesting could not be easier — just kick over the tower and sift through the compost to find your potatoes.
“Towers are good for people who enjoy new potatoes,” Goossen said. “You can make an opening in your tower so you can go in and harvest the young ones.”
Although less familiar, potato towers are nothing new, he said.
“A lot of people like them because it’s fun to play in the garden with new things,” Goossen said. “That’s reason enough to have them.”