I've got some potato bags going and it is about time to do my first add of dirt. I've read that you can also use hay instead of dirt to make the stems grow roots and potatoes. Has anyone tried this? I'm nervous they wouldn't turn the stems into roots that grow potatoes with just hay.. but then again.. it would be easier to keep the plant from being too wet in areas. Actually, I might do a mix by loosely putting the hay in and then filling with dirt around that.. hmmm..

I'll be interested in hearing what others have to say on the subject, but I've had more success using leaf litter mixed with some dirt than anything else. This year I'm recycling soil I've used for microgreens mixed with ground up leaves.

I have resisted using just hay because I am worried about mold growing in there after it gets soaked.

Thanks Wayne! Hmm... I'll have to try that. I have 6 bags going right now, 2 felt ones and 4 purchased 'breathable' bags that seem more like plastic to me. I'm nervous about the plastic ones, but we'll see! The felt ones were planted earlier and I've added a mix of hay and dirt to see how that does. I bought some peat to try in the other bags - I was going to do a few bags with just the peat and some bags with just hay to see what happens. I'll let you know!

Do you ever give them anything in the way of fertilizer? I've been avoiding doing so because I don't want to make them focus on the greens at the cost of the potatoes. Also, how long before you think I could try to dig up some new potatoes? I think I'm supposed to let the greens on top die before I 'harvest' - but some people just dig up a potato here and there too, I've heard.

My experience has been that all potatoes do not grow 'UP" along the vines. Mine all stay underground. The hay, or mounding, helps prevent the potatoes from being exposed to light, which can result in a "green" potato that develops solanine, which can be poisonous. You need to prevent them from being exposed to sunlight, so mound with dirt or hay.

When they start to flower, they are beginning to set fruit, and you can start to harvest new potatoes. Let them grow longer for larger potatoes.

Thanks Linda! My first two bags are now full to the top with dirt. Well, hay/dirt/peat.... Now all that's left for those is to get bigger and flower. The 4 bags I started later have ALL sprouted all 12 seed potatoes! I'm completely impressed. They've just sprouted though so it'll be a little before I can add dirt.

BTW, in this bag, the potato was actually pushed up. I'm just planning on leaving it as it will be under dirt once I add the first round. Is there any reason why I should make sure it is under dirt right away?

I tried just hay in potato bags. Only got a few potatoes. Think dirt will be much better. Hay does not have much nutriments.

Good to know! I currently am trying dirt/hay mixed, we'll see how it goes. I'm going to try a peat fill this year as well.

I'm amazed at how great these potato plants are growing! I've got 2 bags fully filled to the top already and the plants are starting to flower!

I did alot of potatoes in 30 gallon root pouch bags last year. Covered in potting soil and then munched with straw. No good. I didn't get many potatoes compared with in ground. Those bags get really dry especially towards the outsides. I read you can bury them in the ground but then why use the bags? Too much work. I have two pots only this year because I had so many leftover seed potatoes. My main plot is a raised bed made by straw bales as the outside. This works well. Grows good potatoes. Also the end of June is quite late to start potatoes they are a cool weather crop. I started mine late I think beginning of April. I am growing Yukon gold Yukon gem purple majesty and a red one I think is desierre or something. Labels are buried. I hill them with dirt and then mulch them thickly with straw. One year I just covered with straw and the mice voles and rats got most of them. Good luck!

Oh they do need fertilizer. Don't worry about early on but after a while make sure it doesn't have high N. P and K should be high for root crops. Kelp is good.

Thanks! Up here in MN, "cool weather" timing is a little different. We still get freezing temps in may. That said, I would've started them earlier had I known I was going to plant potatoes earlier.