Pot Roots

MissyWeitzel · 2024-05-22T16:30:06+00:00

I know we have discussed pot roots before but I couldn't find it and it didn't have its own thread so I'm starting one. I know I read about it in one of my A...

Teddahlia

KitCMC We tossed the bag but I believe it is a type of blood orange. Probably a sport that has more "blood."

KitCMC

Teddahlia bloodiest orange 😂

Dahlia53

Please forgive my ignorance about pot tubers... I thought that they were grown from a small tuber in a 4" pot, but in reading this I see I might have had it wrong all this time. They're grown from cuttings? I ask because I want to keep some varieties, yet not put them in the ground. I have some small tubers that would easily fit into a 4" pot, Dick Parshall style, but I think it's far too late for cuttings and I don't have lights or a grow setup, I'm a long time hobbyist. Maybe I should just let the varieties I'm on the fence about, go. I only have energy and time this year for about 50 varieties and I have 70 and like or love them all so I thought pot tubers might help me to dither about them for one more year.

I just pulled the saran wrapped tubers out of storage and they look good, no sprouts on most yet, or sprouts just beginning.. I love the saran wrap for that.

I have another question about how to tell good stock from bad, and if open centers the first year you grow a variety means that variety is bad stock and will always have open centers - but maybe that is for another thread.

Thanks as always, Ted and other pros who patiently help answer our questions.

Teddahlia

A pot root is most often created from a rooted cutting but small tuber pot roots are just fine, if you know the stock is good. A rooted cutting already has leaves and diseased plants are culled but a tuber is a "pig in a poke " Many people do "big tuber" pot roots too but the tuber needs to be reduced in size to fit the pot in many cases. I have found that the big tuber pot roots rot more often as the tuber is getting old and subject to rot as compared to a rooted cutting that has all new roots.
I knew a person who knew he was moving and he potted up 200 gallon pots with his favorite varieties and had a 98% success rate when he planted them at his new house the next year.
One of the advantages of pot roots is that they take almost no space in the garden. In the UK I found out that "dahlia variety collectors" would save most of their varieties only as pot roots for several years at a time as they had very small gardens but wanted to keep over their favorites for a later year. I have saved one for 6 years and then grew it and it was perfectly healthy.

Open centers issues demands a long post but we cull them if we have other
good stock. Why chance it?

Dahlia53

Teddahlia Thanks so much for this detailed answer to my questions. I will cull the open centered ones and focus on small tuber pot roots and ask any questions at the next dahlia talk - or if you know of some good articles on pot tubers, I am interested in growing about 30+ varieties and keeping them in the 4" pots if there's a way not to plant those in the ground. (and how to keep them alive in such tiny pots.) I wonder if growing the small tubers point-down is advisable. I tried some of this in the garden last year a la Dick Parshall but didn't take good enough notes on which ones were planted that way. I think everything made tubers, though.

I may be losing this garden space of 14 years (not my land) so I probably should try to make pot tubers of all my favorites, but I'm in a 3 month intensive course and had to go back to gardening work to pay for it in my 70s, so I'm not really functioning that well in the garden! 😄

LoveLanguageDahlias

I made 10-12 pot roots/tubers last year from extra sprouts or pinched tops. I wanted to see how they would work for me...I let a few grow into massive, full sized plants and several others I grew next to the original plant and kept pulling off all of the blooms and cutting the plant back a little to send all the energy to the tubers - the ID was confirmed when the mother plant bloomed. I grew the pot roots in 4" aluminum flower pots from Ikea (had to punch holes in the bottom). They were really compact! I dried them upside down for a week or two them moved them to the basement. I used them for cuttings this winter, and could have taken 20+ from each clump. I stopped at 10-ish, and I don't even need that many.

Teddahlia

"I made 10-12 pot roots/tubers last year ..." You are now officially an "advanced" grower of dahlias. I leave my pot roots(4 inch pots) in their pots for the winter and they are stacked up in the garage where I store tubers. If I use the pot root for cutting material, I change out the soil.

LoveLanguageDahlias

Teddahlia 🙂 I took some of my pot tubers out of the pots in the fall(to see what was going on in there!), and some I left in because they were packed in so tightly I couldn't get them out until they dried a little over the winter and shrunk!

JessieC

I’ve had my pot tubers warming up in various stages and they’re so nice to have! I spent a lot less time fussing over tubers in storage this past season, because I knew I had the pot tubers as well. I also left a lot more tubers in the ground, which was a gamble. The winter was extra cold, but I can see quite a few that survived.
And I just reminded myself to save those late cuttings for more pot tubers. It’s been such a good method for me. Thanks @Teddahlia for explaining it so well.

KitCMC

Was there a post at some point about hard to keep varieties? I have a vague recollection of that conversation, and possibly a list of the poor keepers? I’d like to make pot tubers of varieties that tend to rot in storage, or are poor tuber makers, and would love a resource if it exists.

Dahlia53

I forgot to ask what medium people like to use for growing their pot tubers. I have coir, peat moss, and various potting soils. What do people prefer - and is it too late to try to take cuttings for pot tubers (if I have time and skill to do it?)
thanks.

Krista

Dahlia53 I’m glad you’re asking — I’d like to move away from peat moss but have always used Sungro and Pro-Mix products for cuttings. I’m interested in wool as a medium and I wonder if someone here has tried it before.

Teddahlia

Potting soil: for pot tubers: Avoid any soil that talks about retaining moisture. Moisture retention kills pot tubers and dahlia plants. That may include coir but maybe not. There are regional brands of potting soil so our good one from Pac West used by many greenhouses locally is not sold in your area. It is peat moss based but has rotted tree bark too and pumice. I like pumice in small amounts. Too much rotted bark material is not good either. Earthworm castings are touted to be the miracle food and medium for plants. A local brand is called Black Gold and the "black" is from the earthworm castings. That mix is a bit too heavy for me but otherwise good. This subject has the potential of endless discussion from gardeners all over the USA.
Cuttings for pot tubers can be take very late , even through June. I would "over fertilize" them to get the plants big enough to make a good root ball. Most pot root grower sare not much for fertilizer as the the theory is you just want small plants with small tubers and not 6 foot tall plants in 4 four inch pots.

Dahlia53

thanks, Ted! We can get Black Gold here but for now I am using my leftover potting soil from last year that has good drainage. Good to know about taking later cuttings. I've never done cuttings and would like to try that just for fun.
So if I fertilize, do I just want to encourage foliage and not let them bloom if I am doing a flat or two of 4" pots and don't want 6 foot plants in 4" pots? Thanks! I'll be back for more info I'm sure. It will be interesting to see what endless discussion may come of this. 😄

Teddahlia

A few days ago, I bought a broken(50% off) bag of Black Gold and it was waterlogged and I struggled to load it into the minivan. I do not like soil that gets that heavy but I will mix it with some lighter mix and all will be well.

Teddahlia

Rock wool is an old fashioned alternative product. One of our older club members used it for many, many years. It is not sheep's wool.

Krista

Teddahlia Ah I just looked this up, thank you, I was confused! That does not sound like a product I want to be working with.

ksc

I had tons of scrap Rockwool insulation left over from construction projects so I used it as packing for tuber orders. I was going to try storing some tubers in it, packed in plastic shoe boxes. Unfortunately I forgot but will try next year. It has qualities similar to vermiculite so might just work without the mess of the vermiculite.

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