My climate has two seasons: very hot and very dry, and rather cold and very wet. Potatoes aren’t wild about that. Sometimes potatoes can survive through my summers, but mostly only if I put them in full shade and water them well.
Which makes me wonder. Would it be possible to adapt potatoes to grow through my winter instead?
Potatoes seem to be perennial in my (zone 7b) climate; tubers left in the ground through the winter will sprout up in spring. So it seems like that may be a path towards growing potatoes as a fall/dormant in winter/spring crop. Not exactly the same as a winter crop, but similar in when I would plant them and harvest them.
Even better is if I could gradually adapt them to be fully hardy through my winters, and have them actively growing all winter. I would love that. That may be tricky with the usual Solanum tuberosum, but Solanum ajanhuiri is a (much less common) domesticated potato species with much greater cold tolerance. I’d need to be a full growing zone warmer for them to be able to grow all winter long, but even if they only needed to go dormant for two months (January/February), that’s an extra two months of cold and rainy growing season for them (December/March).
I’m thinking it may be cool to adapt potatoes to be a plant that I sow with my earliest winter crops (August), and harvest with my latest winter crops (May).
Not this precisely, but I did grow potatoes as a perennial at my old house. I didn’t harvest them, just let them do their thing. They would go dormant in the summer (I didn’t water them but they probably got overflow from the neighbors) and return in the fall. I shouldn’t think it would take much to grow them for harvest. Potatoes harvested would probably be small.
I grew potatoes as a perennial in California in the East Bay. Winters are wet and mild there. Summers are dry. They went dormant in the summer. Summer was basically our winter as far as growing plants was concerned because of the drought and water use restrictions.
I have a friend who has potatoes overwinter in western Illinois zone 6a last winter. I have potatoes in the ground in my garden now in the same region. Some of them are from true seed and some of them are from my friend’s potatoes that survived last winter. Am waiting to see if they make it thru this winter.
Overall our winters are becoming more mild with less snow, no persistent snow cover, and episodes of days or weeks above freezing. However we get whiplash Arctic air outbreaks that can drag temps down to -25F and with no snow cover that can kill some plants. Time will tell.
I had some of the “perennial potatoes” from OIKOS when he was still selling individual non-bulk quantities.
A few plants lasted two years but eventually gave up.
Cool! I’m happy to hear potatoes can be grown during the winter in California! California is much warmer than Utah, but the climates are similar in rainfall patterns.
Potatoes I missed readily overwinter and grow next spring even here in Northern Sweden. Even the tiniest minitubers. One would think they should die once frozen solid but they don’t…
Our ground probably doesn’t freeze as deeply as it might in Sweden, but it certainly freezes, and potato tubers left in the ground commonly sprout new plants in spring. Very often they do it too soon an get killed by a later freeze.
My very limited success TPS was with some that made little bitty tubers and those I missed in harvest came up the next spring and they have been doing it ever since. They are solid blue and very tasty, but they haven’t gotten any bigger over the years. All those impossible to find, tiny tubers are probably why they keep coming up each spring. Any vines left growing die down in summer and I just leave them there to sprout the next year. Sometimes they sprout later in fall and get frozen later.
As far as actually growing them over winter, I would guess it isn’t possible here. Tubers live in the ground over winter fine, but any above ground growth doesn’t seem any more frost tolerant than tomatoes.
(Nods.) Great big tubers would be far more preferable than little itty bitty ones, of course, both because you’re likely to get more total harvest and because you’re far less likely to miss them. But a plentiful harvest of little itty bitty tubers doesn’t sound bad. Especially if they’re tasty and tender like new potatoes.
Last year I had some that overwintered and came up in the spring but I thought they were all dead because the ones on top of the ground when they froze they turned to mush
I had one that came up right after the last average frost date, and then we got a late SNOW two weeks later (snow!), and it died down to the ground. A month later, it merrily grew back, and went on growing through the whole summer. So my guess would be that if there’s enough energy stored in the tuber, they can rebound from sprouting too early and grow right back when the temperatures are warmer.
My other potatoes this year were in full shade under an apple tree, so they had a fair amount of cold protection (and a lot of sun protection). They produced smaller tubers, but a lot more of them, and the tops only died once we started going below 24 degrees Fahrenheit. That canopy of leaves above them definitely helped!
From what I’ve seed that is true but if they get pretty large before a frost takes them down, or if happens to them more than once, the yield is greatly reduced.
That’s related to and one of the reasons why I’ve pretty much given up on potatoes except for growing just a small patch each year. It gets hotter and dryer here sooner than it used to. I responded to that by planting earlier, I’ve had potato vines nearly ready to bloom get frozen down. Plant early, risk freeze. Plant later, they fry in the ground.
That’s why I switched to sweet potatoes, nothing so far, fingers crossed, has stopped a harvest from them.
Makes sense. I suppose that could be adjusted for by planting earlier under a hoop house, but that definitely increases the expense and bother.
Have you ever tried Solanum ajanhuiri? I bought some seeds of that species from Cultivariable earlier this year:
I only got one sprout out of the 100 seeds I sowed, but I have high hopes that I’ll see more next year.
That species is supposed to be hardy to 24 degrees F, and it does seem to be hardier than the usual potato species, in practice; the top of my Jancko Ajawiri plant still looked fine for about two or three weeks after the tops of the other potatoes were frost-killed.
(Grin.) I love your sweet potato breeding project, and I’m dying to try some of your germplasm, once you’re ready to share it.
