Works well for me.

Of course, that means you need to wash and allow the tubers to fully dry before marking, which can be problematic if you are processing dozens of clumps at the same time and accidentally knock the unmarked tubers over... ( not that I've EVER done that... Ahem...)

Some growers split the unwashed clump, tie surveyors tape with Sharpie on both mini-clumps, and divide in the spring into ziplock baggies with a just-moist cotton ball to encourage rooting and sprouts before planting out. I plan on processing half-clumps this way, and cutting the other half into tubers in the fall like normal to try to cut down on the time I spend in storage preparations. It can be quite time consuming when the collection starts expanding...

Awesome, thanks! I have about 20 tubers, so wash, dry, and mark is no problem.

Sharpie tip: Buy the biggest sharpies you can find. They last many times longer and apply more ink. Cheap $1.00 Sharpies are best used for celebrity autographs.

Thanks! I actually have a red, blue, green, and black fine point on hand (age unknown, but probably five years). I shouldn't need any new ones for another five years.

Now the biggest question is whether I should code the dahlia by color, using the same color ink. Except yellow, which will be black. :-)

You gotta post picts of your green and blue dahlias for me, Morph! ;-)

It seems to me that I've received tubers with red ink, so I wouldn't think non-black would be an issue for longevity. As I have a rainbow selection of sharpies left over from my five year old's leg cast signing party, I think I might put them to good use for famous tuber autographs, too.

Ted's right about the low level of ink from the cheapie pens, though. Normally I rotate through three pens, keeping them point down, allowing them to 'rejuice' from hard use. It's even tougher on them if dirt gets on the felt.

I tried green flowers once--this year in fact, an Envy zinnia. Never again, the color is too muddy and not dominant enough for my gardens. So no green dahlia here, even if they exist!

I actually do have Blue Boy dahlia, but those are violet. Not that I'm complaining, I like violet. Particularly when fronted by a short orange marigold. :-)

In this case, I also have leftovers, so I'm content to kill them on the dahlias. Eventually I'll probably just get indelible pencils or something--I have enough use for things like that and they won't go to waste.