Advice on potatoes and sweet potatoes?

I planted some potatoes this spring and covered them in a thick layer of hay, about a foot. After some rainfall it became about 8 inches. I have never grown potatoes and I did not know what to expect, but I planted a 60lb bag of kennebec potatoes that I found for a good price. After a couple weeks the sprouts burst through the hay and I was very glad, I started pulling weeds and johnson grass as we call it and everything was good. Now, at about the 1st of august I am finding many of the potato plants yellow and the leaves turning brown. I did not water the potatoes at all, and it has been a pretty dry summer here in southern ohio. The dry leaves also had small holes all over them. I had read other people having success with the "Ruth stout method" without watering or using any insecticides, so I did not expect this to happen. I am really saddened about this turn of events, and I suppose I had better pull up all the potatoes with yellow plants, so the tubers don't rot. I read that this might even be the result of some sort of disease, a blight caused by too many bugs. Is there any information you can give me to help?

I might have a pretty poor harvest this year, but I did not make a huge investment in them (except my time). However I was having such great success with the potatoes, before this, next year I was actually hoping to turn a large hay field into an alley cropping system. Making large Ruth Stout rows of decomposing hay and then cutting the hay between these rows. I was planning on planting a large sum of potatoes, and maybe an even larger sum of sweet potatoes. Now I know sweet potatoes are not often used under hay, but it is possible, helps retain moisture and reduce weeds, just as long as the slips are placed directly into the fertile soil with hay pulled aside. Now I am extra worried because sweet potato leaves are edible, and therefore even more alluring to pests, and the hay field i was planning on planting these is even dryer than where the potatoes are now. So I am looking for advice on fixing this problem, and heck, maybe even a diagnosis, because I am honestly not sure why the potatoes are dying.  I attached a few images of how they look.

People growing sweet potatoes in hay

There's a good chance there's absolutely nothing wrong with your potatoes. They are a mid season variety and the info I found says 90 days to maturity so if you planted them in May, they are done and that is why the plants are dying. Go ahead and dig then up and share a picture of your yield! I usually don't water my potatoes either and get a good yield.

Do you know how to dig up potatoes? If you just pull up the plant, you'll likely leave most of the big potatoes down in the dirt and you won't even know it until next year when you have potato plants popping up all over the place. (Ask me how I learned this 😆). I like to use a shovel and go under where they would be growing and turn it over so the potatoes fall out of the dirt. If you have kids, it's fun to let them sit through the loosened dirt and pile up all the potatoes.

I agree that your crop is simply dying back mid-season as the cultivar is apt to do. Such dying back is often accompanied by an increase in fungal disease organisms, but that is normal. In potato production, farmers often think of the season as a race between the plant and its may fungal pathogens. The holes in the leaves look like flea beetle damage. Potato flea beetles

I agree with Jenny and Andy about the potatoes; this is natural and right that they are dying back, and it is proabably time to harvest.

As far as the sweet potatoes, I say don't worry so much, and give it a go! Your alley cropping idea sounds wonderful. Just be prepared to possibly make adjustments as the season goes along. Sweet potatoes grow like crazy in the right environment. I had a ton of grasshoppers a few weeks ago (before I moved the chickens into that part of the garden) and yes, they were damaging a lot of leaves, but the sweet potatoes could handle it.

Chickens, btw, can be great companions to potatoes and sweet potatoes, if you have the ability to protect them from predators in that hayfield. They will eat some of the leaves of both the potatoes and sweet potatoes, but they will also eat a lot more bugs than leaves, and do way more good than harm. This is not true for chickens and fruiting plants like tomatoes, peppers, strawberries, etc, of course; in those gardens chickens do way more harm than good, by pecking and eating half of every fruit that forms. But with potatoes and sweet potatoes they are excellent friends.

My understanding is that sweet potatoes do need a good bit of water. It really depends how well your soil holds water, whether you can grow them without irrigation. If possible, I would lay out drip hoses when  you plant them, and put the mulch over the drip hoses. Then you have the option to irrigate from time to time if needed. As you build the organic matter in the soil, through the methods you already described, you will become less and less dependent on that irrigation over the years. But sometimes, starting from scratch, you have to make compromises to get where you want to go. I would set up the option of irrigating the regular potatoes if possible too, just in case. I think they are a bit more tolerant to dryer conditions, but sometimes it is better to give a good watering from time to time and get a way better yield, than to do without and be disappointed.

The other thing about sweet potatoes is that they make a whole lot of leaves, and it seems to me that they need these leaves to have access to the sun to make those big, sweet, tubers. So just make sure you are not mulching too heavily, too often, and covering too many leaves. If they are happy, they will also send out  runners everywhere and try to take over the whole world. But if they grow where you don't want them you can always trim them back and either use them as mulch for their own selves, eat the leaves (not my favorite veggie) or feed them to animals like cows or goats.

Good luck! It sounds fun!

Jenny Wright wrote:There's a good chance there's absolutely nothing wrong with your potatoes. They are a mid season variety and the info I found says 90 days to maturity so if you planted them in May, they are done and that is why the plants are dying. Go ahead and dig then up and share a picture of your yield! I usually don't water my potatoes either and get a good yield.

Do you know how to dig up potatoes? If you just pull up the plant, you'll likely leave most of the big potatoes down in the dirt and you won't even know it until next year when you have potato plants popping up all over the place. (Ask me how I learned this 😆). I like to use a shovel and go under where they would be growing and turn it over so the potatoes fall out of the dirt. If you have kids, it's fun to let them sit through the loosened dirt and pile up all the potatoes.

You were right the potatoes were ready for harvest! I think they may have lasted a bit longer if I had given them more water and done something about bugs.. However, I wanted to see just how little effort I could put in for the most results.. and I sure got enough with very little effort... I have so many now that I and my family are getting sick of hashbrowns and french fries, believe it or not. That said, I lost 1/3 of the potatoes to fungus, bugs or rot. Even with that much of a loss though I still had a great turn out. It may have been that the soil was too hard under the hay and the potatoes grew in the rotting hay instead of going deeper in the ground, this fall I will loosen up the soil before adding the hay on top for next year.

Here are some pictures of the final turnout, and also some pictures of the rot that took away so many.

I believe that potatoes don't grow below the seed potato planted. They'll grow above it and lateral. That's why some people "hill" them. That will allow the plant to grow more of them and also they don't get greened up from exposure to light.