I am in a mild climate and have never dug up my dahlias so I can't offer much there, but I was worried about the statement that dahlias should be chopped down.

I have always assumed that dahlia tubers are like bulbs and NEED the dying foliage in order to store up power for the next year. But I read an earlier post where someone said that is a myth and you can cut them down immediately.

Perhaps Ted (the REAL expert) could weigh in. Tubers may not need that dying out process so much as tulips and daffs need it so it would save me months of looking at dead branches if I felt safe cutting them down earlier.

This post was edited by davidinsf on Sun, Dec 7, 14 at 0:43

David, Snarq is an experienced grower that makes a living selling thousands of cut dahlia blooms and tubers every year. I'd say she is very 'real' in her experience level, honest in her offered knowledge, and a very kind lady. I hope she stays to share her advice with others here.

Dahlia tubers store best if they are harvested from healthy plants without rot. If you live in a cold climate where they are growing madly one day and cut down by frost the next, there is no need to cut off the stalks. But if you live in a rainy climate where it may not frost but cool rainy weather will eventually kill the dahlias, you are much better off to dig and divide your dahlias before the fungus diseases kill the plants. Those fungus diseases spread downwards to the tubers and infect them. While some varieties are resistant o the fungus, many are not. So if you are going to leave the tubers in the ground in a mild climate place like San Francisco, you need to watch for fungus infecting the plants and cut them off to the ground if you see it. Here in Oregon, those who dig before the rains start in the Fall have an easier time storing their tubers. We dig in October and frost hits us about December 1st.

Thanks CC, Ted and Snarq.

My flippant 'REAL' expert was not intended to be a slight to any of the experienced growers here - it is just my private moniker for Ted, whose expertise seems inexhaustible and has always has great advice and always answers lots of our Q's. I had never seen Snarq as a contributor so I had no idea who she is/was - but again, I apologize if I slighted anyone. It was not intentional.

I guess my predicament does not fit either scenario. I am not digging up and dividing very often and when I do, it is right about this time of year. I still have some dahlias with dried out stalks as it helps me know where the tubers lie when I weed the garden.

I also have 4 dahlias sprouting for next year already (sigh, the penalty for living in a mild climate) so I am not sure WHAT they are up to. They will not keep growing for 6 more months but it will be interesting to see if they bloom normally next year. Regardless, I now know that cutting them back will not affect their virility for following years and I don't need to see dried out stalks anymore at Christmastime, so thanks to all again.

I appreciate you clarifying, David. I had reread your post five times, trying to give benefit of doubt, and couldn't see any other way you meant it. Ah, the perils of communicating without tonal inflection or facial cues!

Sounds like your soil doesn't get too soggy during winter months to rot the tubers... Does it have a high proportion of sand? Or are you blessed with fairly dry winters?

CC

When I re-read the thread, I could see how horrible my communication seemed. But I honestly was not even thinking of Snarq or ANYONE who offers advice when I quickly tried to give a shout out to Ted. Afterward I could easily see how it seemed like I was dismissing Snarq and again, I apologize to her directly, as that was never my intention. I truly value everybody who offers advice here or has questions or just posts pics.

As to my soil -Both. I live in the Avenues and it is basically sand all the way to the ocean. But you add a drought like we have had for 3-4 years and the soil rarely gets very overly wet, as storms always seem to last only 1 or 2 days and then sun again.

I found it interesting that you had assumed dahlias needed to keep their dead stalks like spring bulbs... Never occurred to me, but in a more temperate region that has a slow die-off of the plants (instead of a sudden 'BAM' frost of death that my dahlias experience), that assumption makes more sense.

I strongly doubt the tubers are continuing to store energy or keep growing as the foliage fades, as that is a sign of impending dormancy. And as you have multiple years of tubers in each clump, the maturity of the tubers doesn't matter as much, either. I have been taught that cuttings started in spring need three months to develop well-matured tubers that will store out of the soil... They actually can start developing tubers within a month, and be stored as a dormant pot root in their soil for the best shot at overwintering a valuable variety.

I've heard of several old timers (all long-passed now, grandparents to my contemporaries) who successfully layered tubers in sand within lined apple crates and coal buckets here in the East. I bet vermiculite wasn't as readily available then. ;-) Nowadays, folks I have talked to report a lower success rate when testing sand against others as a storage medium, but that is after severing the feeder roots when dividing. Sounds like your undisturbed clumps do just fine.

I live in Southern California, zone 9b (Mediterranean climate type) where everything grows well (thankfully) and just bought Happy Single dahlias that I adore. Planted them in a huge pot (similar to a barrel pot). New to dahlias so could use advice. Do I need to remove them in December before the rain (if we get any) or can I leave them? Lowest temps are in January. Normal lowest temp winter nights is 39. Rare, but possible could be 32. Mostly 45 at night in winter. IF I am safest by pulling and putting in vermiculite, can they store in the refrigerator vegetable bin, or better off in the garage? Sorry in advance for stupid questions I am asking. I have a pretty green thumb but am totally ignorant of dahlias. Planted some in the ground last year but we had a "Hundred-year snow) of 2 feet that has never occurred here before so only one of 10 is trying to come up. I love these yellow "Happy Single" dahlias and want to see them every year. Thanks for your time.