TPS – How To Have Lots of Fun with a Few Potatoes, part 3

I’ve not written much of late about our potatoes, but there’s a lot going on in that area. This past season (2014) I realized that my ongoing mucking about with TPS (true potato seed) potatoes has resulted in… feral potatoes!

For a couple of years there have been some odd spuds popping up in places where I knew I had not planted potatoes, but initially I thought that they were the work of absent-minded voles and chipmunks. Most of the “wanderers” closely resembled some of the Blue Shetland lines I’ve been working with – sprawly purple stemmed plants with many quarter-sized dark purple skinned tubers with varying purple, white and ivory flesh. When harvesting them, I’m very apt to miss some because they are hard to see in the black soil, and the plants are sprawly both above and below ground, so tubers can be flung far from the main stem. (Shetlands were developed in shallow soil conditions.)

Volunteers. Small potatoes, but they bake fast, and are delicious (even cold) for a quick snack, cut in half, with a bit of salt.

I have a confession to make. I’m one of those evil gardeners who allows potatoes to over-winter in the ground. Furthermore I have been doing this (partially) on purpose for many (25 or so) years, and I have been selecting varieties for over-wintering, among other traits. I know that conventional gardening wisdom is that this is a big no-no, but I don’t really care. (Let’s hope the neighbors don’t come after us with pitch-forks when late blight hits next year). I will not claim that any of our spuds have achieved LB immunity, but I’m pretty sure they’re not harboring this disease. For us, LB shows up in the tomatoes first, and is usually pretty devastating; but the TPS spuds aren’t nearly as affected.

Anyway, this past season the evidence was unmistakable. Potatoes are growing on their own from seed in our gardens! They’re not escaped clones!

Among the plants that convinced me was a volunteer who popped up a couple of feet from where a very healthy Carola (yellow flesh) plant had grown the year before. I had no clue that it was a seedling. I just thought I had missed digging up a Carola tuber, and the foliage looked like Carola. So, I welcomed it and tended it through the summer. But, when I dug them up (photos at right and below), the occasional purple blush on the skin, and purple ring in the flesh told me that most likely our own Extreme Purple had fathered this seedling from an adjacent bed. (Extreme Purple (aka #4) is a seedling of Hurley’s Purple Gold x Fenton. ) The Carola had a really strong seed-set the year before, and I harvested the fruits, but evidently missed at least one. Those seeds will be very interesting to grow out, I think. Haven’t got a name yet for this Carola x (?)Extreme Purple, but it’s keeper – a lot like Carola culinary-wise, and good vigor and tuber yields.

2014 seedling of Carola (mother), probable father Extreme Purple, below.

Another “obviously-not-a-clone” volunteer was a lovely we’ve dubbed Extreme Pleasure. This one had to duke it out in between a passion-flower vine and some rampant mirabilis multiflora, and it certainly held its own.

Extreme Pleasure, above, and its probable parent Extreme Red, below.

Fruits from one plant – Extreme Pleasure

I have never seen so many viable seed-balls on a single potato plant, see photo at left. The tuber yield was very good, culinary quality also very good. I also love the deep red flesh color.

These volunteers are very exciting, but I’ve also been intentionally growing out TPS from my Blue Shetland lines in a more normal fashion. One seedling offspring of Extreme Purple is very promising – it has the intensely dark purple flesh and skin of Extreme Purple, but with big elongated, flattened tubers, and almost scary vigor. (See below.) The first year seedling yielded over 10 pounds of spuds, and the foliage was nearly 5 feet high. We’ve been calling it Son of Extreme Purple, but probably a better name is called for…

Seedling of Extreme Purple

So, I have been pondering about how this all came about, because I mucked about for many years, totally thrilled to get even one viable seed ball. Then, suddenly, about three or four years ago, the new TPS seedlings were blooming and setting seed like crazy.

Fenton blooming

I believe that the most commonly grown potato varieties may have been bred to not set seed, or maybe that characteristic was just overlooked. For more than 20 years we have been maintaining three varieties (clones) with exceptionally good blooming characteristics: Blossom (red skin/pink flesh), Fenton (purple skin, purple and white flesh), and Ontario (white and white). All three are also reliable over-winterers. However, I only got a couple of viable seed balls in all that time from Ontario and Fenton, and nary a fruit from Blossom (which was bred for flowering).

Above, what happens after blooming with most potatoes;
below, fruit set in our Shetland seedlings.

The Shetland potatoes, as I have mentioned elsewhere, are notorious for not fruiting, so I was very lucky to get the one fruit that started all this business. I think that pollen from Fenton and Blossom may have worked some genetic magic with the Shetland seedlings. The Shetland TPS seedlings are now fruiting copiously, so much so that they are self-sowing and have gotten into the compost piles. (Potato seed actually likes a certain amount of abuse, so they are apt to survive our compost process.)

The Shetland Islands are 50 miles north of the northen tip of Scotland, at about 60 degrees N latitude, so the climate issues for growing spuds there are pretty much the same that we deal with here – cold, wet and a short frost-free season – very different than conditions in the northern Andes, the probable original home of most potatoes. So, the Shetland potatoes have had hundred and fifty years or so of acclimating to those Shetland conditions, and they were not bred for mechanical harvest, which is another reason I find them so interesting.

A potato patch in bloom
Cultivation techniques Seed saving and breeding Variety portrait

TPS Potatoes: Who’s Yer Daddy?

I previously posted about two potato varieties grown in 1994 from TPS (true potato seed) I collected from a potato called Blue Shetland (SSE 1184). I am fascinated by Shetland potatoes, which come from the Islands of Shetland, off the Scottish coast. They are colorful inside and out, and their rich flavor is superior as far as I’m concerned, though folks who are used to the usual insipid tasting commercial potato varieties might find the flavor “strong”. My Shetland spuds tend to be small, but the flavor makes up for the size. They also keep very well.

Hurley's Purple Gold potatoes

Hurley’s Purple Gold, the mother plant. It very closely resembles its mother, Blue Shetland.

One of my two Blue Shetland offsprings, Hurley’s Purple Gold, very closely resembles its parent, and I was fortunate enough to collect a viable seed ball from it in 1996. But, after my initial experience growing potatoes from TPS, I was a bit leary of the time and space required, at least the way I went about it the first time. However, last winter I was inspired to try it again by the videos of Tom Wagner’s TPS workshop at Bifurcated Carrots.

Tom has a genius growing method for TPS that speeds up the process, and requires very little space. I don’t have a greenhouse, so all my seedlings are started on windowsills, which makes me very picky about starting seedlings early. Initially, I was going to get some TPS from Tom but I came across the old seed from Hurley’s Purple Gold and decided to go with that.

seedlings from true potato seed

All the seeds went into a little 2″ pot; about 30 germinated; emergent seedlings were exposed to direct outdoor sunlight; and later the eight strongest seedlings were transplanted to a 4″ pot, buried up to their top leaves. The close planting keeps the seedlings leggy, which is desirable in this case. The idea is to have long stems, since the tubers form on buried stems.

This method is so cool – I could easily see and compare color variations in the seedlings very early on (I’m looking and selecting for strong color), and the individual seedlings’ vigor is also quite apparent when they are grown in such competitive conditions. You can rogue out weaklings early on, and not waste energy and space with them.

TPS seedlings in the garden bed

As you can see, I spaced them rather closely in the garden bed. In hindsight, I wish I had given them more room – after my first TPS growout many years ago, I was not expecting full sized plants in the first year. I heaped compost on the plants several times during the growing season, burying as much stem as possible. This is how the plants looked just before I cut them down.

Purple Gold potatoes

Late blight struck the gardens about the second week of September 2010, so I cut all the foliage off at ground level much sooner than I normally would have. It was somewhat tempting to leave them to see how much late blight resistance they had, but I have no more TPS from the Shetland potatoes (they rarely set seed) so I really didn’t want to risk losing them. When I cut them, there was no sign of late blight on them. All our other potatoes had had their normal end of season foliage die-back, but these were still going strong. I assume that’s because they were first year seedlings, and not because they’re all very late maturing.

Digging up the spuds

Here’s an overview of the harvest. For me, digging up seedling potatoes feels like being a young child on Christmas morning. The TPS I used was not hand pollinated, so I didn’t really know what to expect. I grew about 8 other non-Shetland potato varieties the year I got the seed ball. I was hoping for more Shetland-y spuds, with darker yellow flesh, bigger tubers and red and purple skins. Initially when I dug them up, I was a little disappointed not to get more strong yellow flesh. I couldn’t really see the flesh colors very well, because I didn’t have time to cut into them, do photos and maybe cook some up. I just knicked the skin of one each to get a rough idea, and tucked them away until I could evaluate them better.

So, finally, here’s what I got when I properly opened my presents, and I’m not disappointed any more.

Tuber portraits

#4 and Fenton

#4 left, Fenton (probable parent), right

One seedling (#4) was a monster, producing 5# of spuds, some of which weighed 10oz. We haven’t yet taste tested #4, but so far I am very impressed, and I like the really dark skin and flesh color. My guess is that the father was Fenton, an heirloom potato from Mercer ME I got from Will Bonsall via Seed Saver’s Exchange. Fenton’s one of those Congo, All-Blue, etc. blue/blue potatoes, and it’s a variety that we’ve kept over the years because it’s very rugged, productive, blooms profusely, and tastes really good – a nice baking potato. The other parental possibility would be Peruvian Purple, but I think it’s more likely Fenton.

#4 and Fenton

#5 right and parent Blossom, left

The other real stand-out was #5, which obviously was a cross with Blossom. Blossom was bred in Minnesota by Ewald Eliason with an eye for flowering, among other things, and is mentioned in Carol Deppe’s book Breed Your Own Vegetable Varieties. Blossom is a beautiful plant and has very good tasting all purpose pink fleshed potatoes. It’s also very rugged, another of our “old reliable” varieties. Blossom does bloom fairly strongly here, but I have never gotten a viable seed ball from it, whereas Fenton is a more reliable seed producer.

Anyway, #5 is REALLY tasty, and I like the strong red flesh color. The seedling made over 3# of tubers, a very respectable showing, I think. All in all, I’m pretty excited about this venture, though I think I will wait another year before I grow out more TPS, so that I can be sure to give the 2011 growout of 2010’s seedlings its due.

If you’re interested in Shetland potatoes and other TPS projects, Rebsie at Daughter of the Soil has a great post about the Shetland potatoes she’s working with.

Seed saving organizations Variety portrait

Two sibling potatoes from seed

In 1994, I grew out some true seed taken from Blue Shetland potatoes in our garden. Of the 24 seedlings, we selected six to grow a second season, and of those six, we have kept two over the years.

The Blue Shetlands, the parent, came originally from Will Bonsal in Maine via the Seed Saver’s Exchange, and have dark violet skin, yellow flesh, and a tendency to have a violet ring. Seed was collected from the plants in 1987. Blue Shetlands have some of what I call “primitive” potato characteristics, compared to the modern potato varieties most people grow. The more primitive potatoes tend to have smaller tubers, the leaves are a bit smaller in proportion to the stalks, and eyes deeper. They also may send the tubers out through the soil further away from the above ground part of the plant, so finding them all can be a challenge, especially the dark blue skinned types.

So, here’s our Purple Gold, a bit lighter and redder skinned than the parent’s dark violet, but the same yellow flesh, and tendency to have a purple ring.

Purple Gold potatoesPurple Gold potato foliage

…and Rose Gold, a reddish version. I love the rose star in the flesh. They both have that rich yellow-flesh potato flavor – our favorite for skillet fries and potato salad.

Rose Gold potatoesRose Gold potato foliage

If you do grow potatoes from true seed, when you judge the offspring, first look for culinary characteristics that you like, even if the tubers are smaller than you want. It can take a few seasons of growing out for a potato variety to really show its full potential for tuber size and yield.