I don't know where you are in OR, but we had a really wet, cold April and MAY here. I have lost many tubers to rot despite waiting til May- even mid-May, to plant. Anything that small now is likely to have a rotting tuber trying to support the plant. Dig them up and check it out.

If it's rotting you can cut off the rot, spray the cut with lysol, or dip in Sulphur powder or bleach water. Let the cut dry before replanting and don't overwater. Either that or chuck it once and for all. I've had luck with about 50% of the dug up rotted trimmed tubers going on to grow. I have one other mystery stunted dahlia that I finally moved last night deciding that it was lack of sun and not the tuber which felt good and had lots of roots. The jury is still out on that one.

Poochella - we did just what you recommended, and lo and behold, we had a very rotted tuber. We chucked it. THe other tuber was great, and so we moved it; I think it just got chomped too many times by an errant hungry baby squirrel. (It seems to like two dahlias in particular; I've never had squirrels mess with anything before, weird).

I don't know how the move will affect the dahlia, but we're hoping!

Thanks! BTW, I'm in the south end of the WIllamette Valley (Eugene). It was a very wet spring and now it's HOT!

Good for you, I hope the moved tuber goes on to grow and that the squirrel moves to California LOL!

Enjoy the heat and that gorgeous, gorgeous thing called sunshine.

I've had some like that too-rot. And now its extremely hot. Another factor is if you replace some...I mean that some didn't work out, so you dug 'em up and put in another. Then it would take awhile for the new one to get going. I've had both cases. I'm also using a pot to shade the new one. I've been pleasantly surprised that as much abuse as some have taken-getting broke off, etc that its still hanging in there!

Keep "the faith!"