How to Grow Potatoes in Clay Soil

The Snarky Gardener loves growing potatoes even though heavy clay soil dominates his region of Northeastern Ohio.

New potatoes
New potatoes

I recently came across an article on the Internet about growing potatoes in the garden from the Penn State Extension Office. I decided to read through it even though I’ve been successfully growing them for the last 10 years or so. According to this article (much to my chagrin), I’ve been doing it wrong this whole time.

Potatoes mulched with fall leaves
Plants mulched with fall leaves

“Potatoes grow best in soil that is well drained, loose and high in organic matter. Soil that is too sandy, rocky, or clay is not good for potatoes.”

This is true, but we don’t always have perfect conditions. My research found mention of taters being used to break up clay soil back in the day, especially in areas previously covered with grass. I believe the process of hilling up soil and organic materials around the growing plants assists in the soil building process. I’ve used both straw and fall leaves to cover the stems with nice results.

“The soil should be tilled at least 10 inches deep or double shoveled and raked. The PH for growing potatoes is 5.5 to 6.0 which is lower than most vegetables as potatoes favor a more acid soil.”

Um – normally I don’t till and all this shoveling and raking sounds like work to me. Usually I just dig a small hole or run my hoe down east and west to make a furrow. Then I drop seed taters in and cover them up with soil and/or leaf mulch. As for pH, it’s never been a major concern for my little gardening mind.

“Last years potatoes or grocery store potatoes should not be used as seed potatoes, use only certified seed potatoes which are state inspected.”

This rule is usually not broken unless I have spouted stored potatoes and extra ground to bury them in. I’ve been known to plant a potato variety I’ve seen at the farmer’s market if I haven’t seen anywhere else. This being said, my recommendation is to buy certified seed whenever you can.

Potatoes need 1.5  inches of water per week, more during dry spells. Do not water from above but by drip irrigation or soaker hose. Weeding potatoes is essential to disease and pest control, however you can grow potatoes using plastic mulch. The mulch can be cut with a bulb planter every 12 inches and hand planted in rows about 18 inches apart. Drip irrigation works well with this method of planting.

As a rule, I don’t water my garden unless we are in a drought. Spuds I’ve grown in the past seem to have survived just fine without the water. Hoeing and hilling the dirt around the potatoes keeps weeds down naturally. Also, I’m not one to use non-organic materials for mulch, but if you want to, be my guest.

“Potatoes can get early blight which are small circular brown spots with a target like spot in the middle. This will kill plants and is caused by plant debris overwintering in the bed you plant them. Plant rotation is extremely important with potatoes. Do not grow in the same bed for 4 years. Clean up the garden in fall.”

I try to keep from growing members of the nightshade family (tomatoes, potatoes, peppers, eggplants, and ground cherries) in the same place for 3 years, which is the minimum time suggested by most experts. I’m not always able to accomplish this as I grow A LOT of tomatoes and taters. To keep this all straight, I utilize GrowVeg.com planner software. This platform lets me know if I’ve grown something from the same family in a specific spot in the last 3 years. I don’t always take the advice (especially with legumes like beans and peas) but the Nightshade family does get my respect.

“Common Scab is caused by a bacteria that can be in the soil for a long time, even when potatoes were not planted  in that spot. The main cause is decomposing material such as vegetable matter not cleaned up. Using an acid based fertilizer can sometimes help, or find another place to plant.”

The Snarky Gardener’s tubers were infected with common scab a few season’s back. They tasted just fine, but it was a concern. After reading up on the subject and doing a soil test the following year, I traced the problem down to high pH (7.4). I haven’t planted nightshades in that area since and haven’t seen scab on my taters grown in other places either.

Mulching potatoes with straw
Mulching potatoes with straw

My takeaways from the Penn State Extension Office article:

I’ve been growing potatoes in our Northeastern Ohio clay for the past decade. Besides a small common scab issue, I’ve had little to no problems. I do appreciate advice given by people who have WAY more experience and knowledge than the Snarky Gardener. The article was written from the “maximizing potato output” point-of-view. My gardening designs lean towards minimizing labor, soil disturbance (“low-till”) and “outside my property” inputs. This means I might not get the biggest or best harvests, but I will always get something. And isn’t that the goal of every gardener?

I’ve also learned that I don’t follow instructions well (never have, never will). For me, gardening is as much art as it science. If we aren’t allowed to try our own systems and practices, the fun of the garden is removed. And I’m all about having a great time out in my yard, even if it’s hard work sometimes. Nothing beats growing plants, harvesting produce, and eating meals created with food that you grew (even if you are not following the directions).

By the way, here’s a really cool Ruth Stout interview including her planting potatoes. It doesn’t get any easier than that.