Greetings Abbey, all your Russian tomatoes are flourishing and I can't wait to try them. This method does in fact work. The potatoes you left behind tend to be small and so the next year you have somewhat less vigorous plants producing smaller crops than the initial one. It works with heavier soil, no wood ash, some winter mulching (many potatoes die when they freeze) and a fertilization similar to perennials (details later).

Always looking for shotcuts, I just make layers of unfinished compost in these perennial locations, starting with some non-matting mulch the Fall before, plant April 1, and starting in July I collect both potatoes and (more or less finished) compost. Fertilization and some hilling is done by and with the composting matter (the place is full of worms). The returning plants are from potatoes left in the soil under the pile. I used to plant them under wood chips in my sandy soil, with small but carefree crops (always the same places, hard to mow areas), but a waste area behind the garage, which had been backfilled with clay, proved to be the ideal home for them.

If you think you are getting blight (which will not be a problem in a normal year, and I have never seen it, not even last year when I had some blighted toms), you can pick more carefully in the Fall, move the seed potatoes elsewhere, and rotate with winter squash or other large cucurbita, or even garlic or bush shelling beans (all pick-once crops, you don't want to wade through it too often). You can compost as much under the squash as under the potatoes, as cucurbita grow through unfinished compost just fine, and they like 10X10 patches. Garlic and beans will take a thinner layer of organic trash, their roots must be in soil.

About fertilization. You are taking a lot of potash and a good amount of P out by harvesting the potatoes. Lots of organic matter will replenish it, but the same bed year after year will exhaust itself. Potatoes are also one of the more sensitive veggies to the presence of mychorrizae, which are almost certainly there by now. If you want to make sure, you can look for some composted matter near roots in a wooded area, and spread it in the bed. A pound would probably be enough.

Great to hear from you again. I planted your radicchio seeds on August 8th and had a nice crop in the fall. I am growing your other seeds this spring. The perpetual potato patch is growing with a large amount of aged compost. I will take your advice and replenish the area with fresh compost. Thankfully, I have a plentiful supply of compost.
Abbie

Oh yes, here in the tropics of MA potatoes overwinter with ease. Except in very severe winters any tuber deeper than a couple inches survives. What I like about the volunteers is that they make earlier new potatoes - I'm looking forward to some in about ten days. I agree with Glib, by adding compost materials every year one can go on indefinitely. IME, though it's easier and more productive to save seed and plant in rotating patches.

Are you not worried about Late Blight being re-born from those earlier blighted potatoes the next year?

I'm with Anney - this is NOT a year to be planting last year's saved seed potatoes much less encouraging volunteer potatoes. Especially anywhere in the NE US.

Otherwise, I guess I tend to dig my potato rows more thoroughly than you all do. ;)

Dave

I threw my remaining Kennebec potatoes in the compost bin a couple of months ago, because they had a lot of green. While working in the garden 2 weeks ago, I had some space for potatoes & remembered the ones in the compost bin, so I nabbed 9 of them and put them in a grow bed. They're Kennebecs, and supposedly resistant to late blight. I din't do a bad thing, did I?

I too have last year's potatoes sprouting here and there. It does seem like a win-win situation. What I understand from reading, but not from experience, is that a viral disease will increase in your home-grown potatoes year by year until yields become terribly low. That's why everyone buys the certified disease-free starter seeds every year, at considerable expense. I don't know if there's any harm in letting them grow year to year. I figure if disease levels do increase to an unacceptable level, you can always start again with the certified seeds. Although, perhaps it is harmful to allow that level of disease to build up in the soil. I have no idea.

It isn't a virus, it is a fungus - specifically p. infestans. And it isn't the threat to the potato crop although that is a concern, that led to the recommendation to destroy (not compost) volunteer or saved seed potatoes. It is the threat these potato volunteers and saved seed pose to this year's tomato crop.

The fungus that causes late blight in tomatoes and potatoes and that wiped out much of the tomato crop in the NE last year over-winters in potato tubers. You may recall mention of the Irish potato famine in history - same fungus. Those potatoes sprout and re-infect even more of this year's tomato and potato crops. Given the right weather conditions again, that could lead to a major re-infection that could duplicate last year's losses in the NE.

It isn't a win-win situation. It is a lose-lose situation for both you and any neighboring gardeners since the fungus is then wind-borne for miles around.

I'd suggest some research into the disaster in the NE last year and far into the south and west it spread. Then check out all the research and late blight control recommendations for this year out of Cornell University. Then decide if it is really worth trying to save a few dollars or trying to perpetuate your potato bed.

Other gardeners in your area would appreciate it. ;)

Dave

The onset of late blight occurred after a rainfall in early September and so the spores were introduced from the air. My heirloom tomatoes became sick while the hybrid Juliet and Sungold plants stayed healthy. I saw no blight issues with my potato patch which is 150 feet away from the tomatoes and 600 ft away from one neighbor's backyard garden. My other neighbors have gardens over 1000 feet away from my small potato patch. I am hoping that this past winter freeze killed most of the spores from last year's late blight with my tomatoes. However, knowing microbiology, the spores are still viable waiting for the optimal environmental conditions to wreak havoc. A spore- free garden is in the laboratory in a sterile petri dish as tissue culture or a well managed hydroponic system.

My potatoes were down and uninfected as far as I could tell before the tomatoes got wiped out by Late Blight, but because the spores wash down into the soil and infect the tubers that way (before frost) I pulled the few volunteer potatoes that sprouted.

Same here, the toms succumbed in early fall (after an excellent harvest, fortunately). Potatoes are long by at that point. I have been growing potatoes from saved seed for a dozen years with never a hint of blight.

What really pushed the tomato blight around the northeast last year was the mass producers of tomato seedlings in the south. I know that anyone I talked to who had bought plants lost them very early on (early blight).Those that started from seed had either no problem or a little late blight. The extremely wet summer in the northeast was of course the contributing factor.

But the late blight that initially infected all those tomato plants is the same blight that is extremely contagious and infected potato plants as well. The tomato infections were probably killed during the winter, since freezing kills the spores. But any infection, no matter how slight, that your potatoes received can continue in unharvested potatoes surviving underground and start the cycle all over again this spring.

The blight spores infecting the two plants, tomatoes and potatoes, are not different. THEY ARE THE SAME DISEASE.

Do everyone a favor and get rid of all your potato volunteers if you live in the Northeast. Really, it's a risk you and your neighbors should not have to be exposed to. It's easy enough to destroy the volunteers and plant fresh potato slips. When Late Blight has not been an epidemic in a given year and in a given area, you can have your perpetual potato patch.

And your plants in your gardens in MA may have only "gone down" in Sept. or in the fall but in the rest of the NE they were going down all summer long from June on.

It is difficult to believe people could be so under-informed about this given all the national media coverage of the epidemic (and yes, that is what it was called) all over the country, much less in the NE.

Dave