Growing potatoes in raised beds is by far our most successful potato growing method to date, requiring minimal effort for exceptional yields. Each 4 x 8 foot raised bed produced 50 to 60 pounds of potatoes, without fertilizer, irrigation, or weeding.
We’ve been growing potatoes (or trying to) for the past decade on in our wet clay soil. We’ve tried conventional growing methods, heavily amended garden plots, growing in hay bales, planting in trash cans, and just about every other potato growing method you can imagine.
Though we have harvested potatoes, the yields were pretty unimpressive until we tried growing potatoes in raised beds.
This year, we put in 24 raised beds, each 2 feet deep to ensure deep soils and good drainage. Our native soil is heavy clay, and only about 8 to 12 inches deep before you hit hardpan.
Crops tend to rot in the ground in wet years, and there’s never enough soil depth for long-season crops to establish well.
While a dozen of the beds are in our fenced garden, there just wasn’t space for all we wanted to plant. The other half of the beds are scattered around the house and have no protection from deer.
Strawberries, lettuce, and other tender crops were planted in the fenced region, but deer mostly ignore garlic, onions, and potatoes.
That means we’ll be able to grow plenty of potatoes in the unfenced beds around the house without having to worry about deer, but it also meant we didn’t have a dedicated garden hose for our potato beds.
This past year was a record dry year for Vermont, and we didn’t get rain for 60 days straight mid-summer. (Usually, we get a steady inch a week…)
We planted four beds total, each 4 x 8 feet in size, and harvested 240 pounds of potatoes. That’s a yield of 50 to 60 pounds per bed, without irrigation, fertilizer, or weeding all summer. Planted and then forgotten, and with very little rain.
(To be fair, Vermont is exceptionally humid and our native soil stays quite wet even in dry years. I imagine some amount of water was wicked up from the ground, and I don’t recommend trying to grow potatoes in a drought without irrigation in most places.)
Growing your own potatoes is extremely rewarding. These tasty tubers are quite easy to grow, even for beginner gardeners. With just a little bit of effort, you can harvest pounds of homegrown potatoes to enjoy all season long.
One of the best ways to grow potatoes is in raised garden beds. The loose fertile soil in raised beds is ideal for potato production. Plus the beds warm up faster in spring to promote rapid sprouting.
However, there is one key factor that determines success when cultivating potatoes in raised beds – the depth.
Why Raised Bed Depth Matters for Potatoes
Potato plants form tubers along their roots underground. Therefore, adequate soil depth allows the tubers room to size up and expand properly
Shallow planters often force the tubers upwards, leading to green potatoes exposed to sunlight. Exposure to light causes potatoes to turn green and become mildly toxic, with poorer flavor and texture.
Compacted soil can also cause deformed stunted tubers. Loose, deep soil enables the potatoes to swell to their full maturity.
- Prevent tubers from reaching the surface and turning green
- Allow plenty of space for full tuber development
- Have loose, fluffy soil for tubers to expand
- Be shallow enough for easy planting, hilling, and harvesting
Recommended Raised Bed Depth for Potatoes
Through much trial and error, I’ve found that a depth of 10-12 inches is optimal for raised bed potatoes.
Beds around this depth keep the developing tubers covered in darkness, safe from greening. Yet 10-12 inches is still shallow enough for easy digging, hilling, and planting.
Here are some more specific guidelines for choosing the best potato planter depth:
-
For early potatoes, beds at least 8 inches deep will suffice since early spuds are quick to mature.
-
For maincrop potatoes that take longer to bulk up, aim for 10-12 inch deep beds.
-
For giant, impressive potatoes, beds over 12 inches (14+ inches) are ideal.
-
Avoid beds deeper than 16 inches, as harvesting becomes tedious.
-
Standard raised garden beds are commonly around 11 inches deep – perfect for most potato varieties.
The key is to provide enough soil for the tubers to expand, while still being able to easily tend to the plants. Enrich beds with ample compost before planting.
Growing Potatoes in Shallow Beds
If your raised beds are under 10 inches deep, you can still successfully grow potatoes using the “straw method” as follows:
-
Plant seed potatoes in a shallow 1 inch trench, spaced 12 inches apart
-
Cover the potatoes with 4-6 inches of straw or hay, wetting down as you layer
-
As sprouts emerge and reach 6 inches, add more straw to cover stems, leaving just a couple top leaves poking out
-
Maintain the straw layer as plants grow to block all sunlight from tubers
-
Check under straw occasionally and add more as needed to block light
-
Harvest new potatoes after flowering, and maincrop when vines start dying back
This straw technique prevents immature tubers from seeing light, resulting in healthy, green-free potatoes – even in shallow beds!
Ideal Raised Bed Size for Potatoes
In addition to depth, the length and width of your raised beds affect potato plant spacing. Potatoes need ample room for hilling soil or straw around the stems as they grow.
Here are the ideal raised bed dimensions for a thriving potato crop:
-
Length – At least 4 feet long. For abundant harvests, 8-10 feet is better.
-
Width – 2-4 feet wide. Wider than 4 feet is difficult to reach across.
-
Space potatoes 1 foot apart in rows, with 1 foot between rows.
-
In beds under 8 feet long, limit rows to 1-2 to allow hilling space.
-
Prioritize length over width, as potato plants grow along the ground more than outward.
With proper length and width, you can plant successive rows of potatoes in a single bed. Just space varieties appropriately for their mature size. You can also interplant quick-growing beans to climb the potato stems.
Tips for Growing Potatoes in Raised Beds
Follow these tips for the best raised bed potato harvests:
-
Choose early, midseason, and late potato varieties to extend harvests.
-
Enrich soil with compost or manure before planting. Cultivate beds to 12 inches deep.
-
Cut seed potatoes with 1-3 eyes and let cuts dry before planting.
-
Space potato plants 12 inches apart in all directions.
-
As stems emerge, hill soil or straw up around plants, leaving just the top leaves exposed.
-
Hill again once plants reach 6-8 inches tall, keeping developing tubers covered.
-
Water deeply, especially when plants flower and tubers are bulking up.
-
Stop watering once foliage starts dying back to toughen skins for storage.
-
Harvest new potatoes when plants flower. Harvest maincrop 2 weeks after vines completely die back.
-
Cure harvested potatoes in a dark, cool area for 1-2 weeks before long-term storage.
With the proper raised bed depth and care, you can harvest an abundant potato crop without having to dig up your whole yard!
Frequently Asked Questions
How many potatoes will a raised bed yield?
On average, expect 5-15 potatoes per plant. A 10×4 foot bed with 2 rows of 5 plants can produce 50-150 pounds.
What is the minimum soil depth for potatoes?
8 inches can work but yields will be lower. Shoot for at least 10 inches for best results.
Should you mix compost into the soil for potatoes?
Yes, mixing in compost or aged manure improves soil texture and nutrients for better tuber growth.
Can potatoes stay in raised beds over winter?
No, leaving potatoes over winter invites disease. Remove all plants after harvest and rotate crops yearly.
What vegetables pair well with potatoes?
Great companions are bush beans, brassicas like cabbage, and herbs like dill. Avoid planting near squash or tomatoes.
Conclusion
When using raised garden beds, providing potatoes with adequate soil depth is crucial. Aim for 10-12 inches deep for robust maincrop potatoes. For shallow beds, use the straw method to mimic soil depth. With proper care, your raised potato patch can yield heaps of homegrown spuds!
Planting Potatoes in Raised Beds
We filled out beds with 2 parts screened topsoil, one part compost, and one part peat moss to help lighten otherwise heavy soil. Potatoes also like soil that’s mildly acidic, so a bit of peat moss helps both lighten heavy soils and adjust pH. It also helps retain moisture, which no doubt helped us with this dry summer.
I dug two trenches down the bed, each about 10-12 inches deep.
We happened to have 4 pounds each of 4 seed potato varieties (for a total of 16 pounds). I planted one variety in each bed, and I’ll be honest, that was overkill.
Four pounds of potatoes barely squeaked into each bed, with 7 to 8 plants per row and two rows.
We didn’t cut the potatoes at all before planting.
I’d imagine you could plant around 3 pounds of whole potatoes comfortably, or 1.5 to 2 pounds of potatoes properly cut before planting. That’d give the plants more space, and likely yield around the same amount.
I dug each potato down slightly further, meaning they were planted at around 12 inches deep.
After planting, I covered each potato with 4 to 6 inches of soil. Once the first sprouts were about 6 inches tall, I pushed over the rest of the soil to completely level out the bed.
Pushing over that soil after they’d sprouted was the last time I tended these potato beds in any way. That tiny bit of “hilling” took them from an original depth of about 6 inches to 12 inches deep, and helped to support the growing potato plants.
They grew quite tall in the end, but I didn’t hill them any further.
As it turned out, 2020 was a crazy year and there wasn’t much time for tending potatoes. We were never able to get an irrigation setup for these beds, since they were so far from our fenced garden.
The potatoes were on their own…and they did just fine.