Digging and dividing 2025

Juliarugula

The good news is, dividing is moving along pretty quickly this year.

The bad news, of course, is that tuber production was a bit less than usual. The weather this year was pretty hard on the garden - I was hoping I wouldn’t see it reflected in tuber production also, but no surprise really.

Here’s something I don’t understand though, and maybe someone can help me out with an explanation. This spring, I started more tubers early in pots than I ever have before. By the time I planted them out, some were respectably sized plants, some were still small, but they all seemed to get a jump start on the season compared to my tubers planted directly in ground after frost.

However, so far, it seems that these early-started plants are way way way lower on tuber production than plants started in ground. Like, several have had no salvageable tubers other than the mother. Any ideas why this would be?

SteveM

Juliarugula Any ideas why this would be?

I assume your comparisons are of the same variety and grown in the same part of the garden? Did you grow your potted plants under lights before planting out?
I thought I experienced this a few times, but only a few times, so I never tried to diagnose the problem. I thought perhaps it had something to do with the nutritional differences between my potting mix and garden soil. Another possibility was: Since I grow my potted plants under extended long-day lighting before i plant them out, maybe they were not exposed to the short days of early Spring that encourages early tuber formation.
Let us know if you figure it out.🙂

Bessie

Juliarugula it must be really frustrating to get to the end of the season and not get tuber production!
I don't have any personal experience, but figured I'd check what AI says causes potatoes to not plump up. This Gemini AI search is not very helpful, since it gives lots of possible causes of skinny tubers, but may give you some hint of what in your fertilizer or growing season "went wrong".
https://share.google/VC0ByuHiWydGy25AQ

Krista

Juliarugula way way way lower on tuber production than plants started in ground. Like, several have had no salvageable tubers other than the mother.

I had this exact experience last year; finding only mother tubers plus a mess of long plump roots, or nothing mother even - just root balls. The only difference was that I didn’t start a single tuber early in pots. I grew almost exclusively in grow bags last season and summed it up to nutrition, and some late planting.

I was really frustrated so I’m glad you started this thread. I’m curious! I planted in-ground this year, and on-time, and am anxious to see what my tuber production looks like. For my most coveted varieties this year, I cut the plants back aggressively, early, hoping to encourage tuber development?

I’ll get a soil test next year and have been considering applying potash in August, if we’re low enough in potassium that it makes sense. Hoping for more ideas from others here to prevent this in the future. It’s such a let down at dig time, so I’m glad to hear you haven’t gotten to any favorites yet!

Teddahlia

Anytime a dahlia is started in a pot, the tubers are compressed into a tighter ball. Tighter clump, fewer tubers. If I were planting them into the ground from a pot, I would be adding lots more fertilizer, especially nitrogen to the plants as they are ready to take it in and grow. Remember they are 30 days ahead of the tuber plants and with extra fertilizer it is possible they may send up additional stalks that would grow more tubers in addition to the initial compressed clump.

Juliarugula

Teddahlia it didn’t really look like the effect you’re describing, though (I see that on cuttings that have spend too long in a pot often). It was more like the mother tuber was there, and everything else was just those long, wide roots you get sometimes. Not compressed or root bound - spread out like a normal clump. It was almost like the tubers never bothered to thicken up.

Next time I find one I’ll have to take a picture.

Teddahlia

I have found that planting an undivided clump(full sized but not huge) into the ground tends to give me the most tubers. I know a commercial grower that does a version of that as he harvests a couple or three of the easy tubers from the top of the clump and then uses the remainder of the clump to plant whole in the Spring. He says many of the below average tuber makers respond well to this practice. He sold me (we actually trade) a nice tuber of one of those varieties. The bat guano lady(she is actually named Victoria and does not come to meetings any more) about 6 years ago (may 10?)had the biggest tubers of several varieties that I had ever seen. She won the bucket of bat guano at one of our meetings and grew the dahlias in an onion field where they grow onions in what is called "muck soil". That soil is where there was a lake and and they drained it to create an onion field. I tried some guano the next year but had mixed results.

Juliarugula

SteveM problem. I thought perhaps it had something to do with the nutritional differences between my potting mix and garden soil. Another possibility was: Since I grow my potted plants under extended long-day lighting before i plant them out, maybe they were not exposed to the short days of early Spring that encourages early tuber formation.

I was sort of wondering about either of these two things also.

Re:comparisons. Not side by side, but yes, nearby in the garden, same varieties. They were also varieties that I’ve grown before, so have some idea of the usual tuber making habits in my garden.

Probably won’t ever know - I was just curious if others had the same experience and had thoughts.

Juliarugula

Bessie it must be really frustrating to get to the end of the season and not get tuber production!

So far, I’m mainly digging varieties I was planning on cutting from next year’s garden, so no heartbreakers yet! Also, since I just grow for myself, as long as I get a few tubers of the varieties I’m carrying forward next year, I’ll be ok. But there are a handful of plants that I sure hope did ok underground. They’ll probably be some of the last ones dug, so fingers crossed!

Teddahlia

"I cut the plants back aggressively, early, hoping to encourage tuber development?" If "early" is near the beginning of the growing season and your intention is to get more sprouts from under the soil that will make more tubers, that certainly would work if you give them extra fertilizer(nitrogen). If you cut them back in the later part of the season, the plant does not have the chlorophyll it needs to grow tubers.

Krista

Yes, I cut back early, after the first bloom(s) confirmed a positive ID for the plant. These plants grew healthy foliage from a few sprouts coming from below ground (not side shoots from the main stem) for the rest of the season.

Teddahlia

The other number one reason dahlias do not produce tubers is that genetically many varieties are poor tuber makers. I say this all the time but it is very true. I cannot imagine something like Chilson's Pride or Cornel or any number of Swan Island varieties not making tubers in your garden.

Teddahlia

While we were digging:
Two days ago a Bald Eagle flew over the garden at a fairly high altitude. Yesterday, this overactive woodpecker kept hammering away. After 15 minutes he flew away. New cellphone has a telephoto lens.

Juliarugula

MissyWeitzel let us know - I’m curious! Spring was so rough this year. I’m really thinking it has something to do with it.

Teddahlia Pileated Woodpeckers are one of my favorite birds! They’re so cool.

MissyWeitzel

I have been digging and dividing for 2 weeks now and tuber production is definitely down for me too. I attribute it to the unreasonably hot late spring and early summer.

I planted about 60 tubers of all different varieties on July 29th this year. The plants are only now just blooming but they have been happier and healthier than anything else the entire time they have been growing. I'm saving those to dig last, but I am super curious to see what I get for tuber production from them.

Teddahlia

Wood peckers like metal fence gates and use them to call for a mate by hammering very loudly. One have them must have been desperate as he went on for a very long time.

Teddahlia

Picture posted to Facebook. Here is picture not posted to Facebook of it and it's sport.

Juliarugula

Teddahlia speaking of sports, I’ve been meaning to ask. Is Hollyhill Yellow Black Beauty ( or is it Hollyhill Yellow Beauty?) a sport or a seedling of Hollyhill Black Beauty? If a sport, do you find it to be pretty stable? I’ve really loved it this year. Such a rich golden yellow!

Teddahlia

"Is ~~Hollyhill Yellow Black Beauty~~ ( or is it Hollyhill Yellow Beauty?) a sport or a seedling of Hollyhill Black Beauty?
Hollyhill Yellow Beauty is a seedling of Black Beauty.

Teddahlia

First year seedling garden, harvested, cover crop(Rye) planted, and rough tilled. Second year seedlings next.