Harvesting TPS

[larryrider]

I am new to Tom's forum and to TPS. I see that some of my potato varieties, Kitahdin, Island Sunshine, and Keuka, have started to form seed pods. Miracle! It looks like the flower stem goes from upright to angled down as the seedpods form.

When can I harvest these? Is there a danger that they will fall off before they are ready? How do I make sure I get them all?

any advice appreciated!

larry rider from Lynnwood WA USA

[Tom Wagner]

Larry,

We've talked over the phone a few times and here's what I suggest we do:

I'll stop by the garden and take a look at your potatoes..Katahdin, Island Sunshine, and Keuka Gold. I will make a few quick observations and then suggest a time for berry harvest and perhaps a time for seed extraction.....after which you relate on this forum how you went about it. Fair deal?

Tom

[larryrider]

That is a great deal. I would be happy to share what I learn about how to harvest and extract these delightful seeds from potatoes.

[wingnut]

Is size any indication Tom? As I have a few that are just huge.They started falling off my last row of white flowered (german bb I think) plants so I picked those. Just a slight touch and they fell off. I have other berries that a darn near quarter sized, would those large ones be ready?

[Tom Wagner]

Wingnut,

Leaving the berries as long as possible is the way to have fully sized seed with good seed coats. I know it is a problem when the variety is right next to another variety and when the berries fall off...which vine was it from?

Obviously I need to get down to your place soon and give you a quick training session on maturity needs of berries.

[wingnut]

Both sides of my bed, that I pollinated with Caribe. The ones closest to the chickens/brocolli were the ones actually falling off. The others came off with just a touch. I have had none fall off in our patch, but some are quite big. I'm not worried about getting them mixed up as I check them at least 10 times per day.......

[larryrider]

About Harvesting True Potato Seed:

Thanks Tom for coming out to the Ananda Community of Lynnwood yesterday and showing me about potato seed. This is what I remember of what you told me:

The seed pods are mature, and ready to harvest, when they have been on the vine at least two weeks after the flowers drop. Later is better. If harvested prematurely, the seeds will not have a thick enough seed coat, and germination will not be so good. the berries should have a whitish-green look at the bottom, not all green.

They may drop off on their own, but if they do they may still not be mature. But after they leave the plant, either dropping or being picked, the seeds will continue to mature some more.

Is that correct?

[Tom Wagner]

Thanks, Larry, for the visit to Ananda. A very good tour of the community gardens.

The seed pods are mature, and ready to harvest, when they have been on the vine at least two weeks after the flowers drop.

The berries are near mature few weeks longer than two weeks after flower drop.

I use a rule of thumb of about 6 weeks plus after blooming and the bud drop is at least a week or so after blooming.

[larryrider]

Tom,

I don't really know when 6 weeks from blooming is - lots of the berries have a whitish underneath, and I wonder if you can give me any more advice on how to tell if they are mature. Should I wait til they start to fall off? Should they be softer? How do you tell?

thanks,
Larry

[larryrider]

Another question - some of the pods had a little black (blight, I presume) at the base of the seed pod, and fell off. I saved them, but now they are turning black. I assume I should throw them away and just keep the good ones?

And what is a good way to store them - ziplock bags? airtight? cool, dry, dark?

thanks
Larry

[Tom Wagner]

Larry,

I know for a fact that the late blight hit your area a few weeks ago...and affected the flowers as much as anywhere else: stems, leaves, etc.

The blacken fruits, if small, are probably useless.

I will make a point to stop by and do an extraction of some of the fruits for your edification. Once that is done...you will see the evidence of good seed or not.

[containergrower]

Is it safe to assume that berries I first noticed 8 weeks ago are ripe and seeds have fully matured? Some have pale purplish pigments developing on one side.
I want to remove all the ones I think might be mature because the plants are now diseased with what I suspect is blight and I really want to salvage what I can if I am unable to control the infection.
I'm fairly certain they are all on the 'Black Irish' plants, but won't know until harvest or when I uncover the tags that got buried in 2nd hilling.

[Tom Wagner]

Potato berries are mature enough to pick from six weeks to over eight weeks after blooming. The berries ought to set around in a cool dry place for a few weeks more and/or they turn a bit soft and more yellowish. That allows the gel to slip from the individual seeds. I have yet to extract any seed even though I picked some berries a month ago.

I usually add to my discussion right about now how I use TSP to remove the gel around the seed and Chlorine bleach to sterilize the seed.

[containergrower]

Tom, thank you for more clarity on harvest and storing berries for awhile prior to removing seeds.

good to know I did the right thing last year when I left the 3 berries 1 plant produced on my desk in a small bowl until mid-February when I husked them from the then-very soft little berries.

Germination of the ones I planted early in March was excellent & very quick, considerably faster than a couple of varieities from Tom were. I think they might've originated on a yellow finn or perhaps yukon gold based on 2 round yellow new potatoes i pulled up and ate this evening.
perhaps the former since those potatoes were at the surface and not 10" deeper where the original crown had been before being hilled heavily a couple of times.

I researched the disease & based on everything I found, those potatoes most likely have purple mop top. [the phytoplasma type, not the virus]
bummer!
this evening I harvested berries from the most-affected vines and tomorrow will remove top growth that will go offsite to the landfill vs being composted and then I can hope of having an ok harvest in 2 weeks or so.

glad to find plants on either side also have berries forming that could be as much as 4 weeks old. Hope some are viable whenever I have to remove them.

thanks again for the information and advice.

[Blythe]

I have some Thunder Row TPS plants in my garden... they are full of berries, some have turned purple/black (but look healthy and ripened). This is a dark blue/purple potato so are these dark berries the ripened state or have they become "useless" for some reason as you pointed out above? I just checked my photos and it looks like I had berries and blossoms, both about 3-4 weeks ago. If I'm understanding the above correctly, I should let them go another 3-4 weeks before harvesting them, correct? TIA for any information you can provide (I'm in south-central Ohio, btw).