The whole dahlia saga-- 2025 wasn't great and 2026 probably won't be either.

2025 was my first year growing dahlias and I wanted to be really careful not to introduce gall or other disease to what so far had been a pleasant gardening experience.Other than a peony with virus, things had been going well. In the interest of protecting my yard from dahlia diseases, I opted to grow everything in pots for the first year with the idea that the second year the good ones would get planted in in ground.

I added approximately 139 dahlias varieties, mostly single quantities but some duplicated varieties. 

During the season, 18 of those failed to grow. I didn't properly protect from rain and a chunk of them came in wrinkled and not sprouted. I should have presprouted and covered.

I purged 6 that were import tubers and wrong variety- plus ugly flowers.  

I purged 6 varieties for obvious virus.

I purged 14 so far for crown gall, the most recent was BQ Jean which I found crown gall on today. Always presprout your tubers! I'm sure I haven't hit the end of my crown gall, for reasons explained below.

I purged at least 4 for leafy gall- but this has seemed mostly limited to just the import tubers. This is important because leafy gall spreads really easily in water- so if the gall was from water intrusion into the pots I would be seeing a lot more leafy gall more than likely.

I still have 10 odd crusty tubers that MSU states is not gall, but, I bet if I presprout them that they will have gall. At the time I sent to MSU though, the 'lenticels' were still too small for them to call it gall and they don't test, they just look at them. They did test negative for nematodes, so at least that is ruled out.

The most important lesson I learned is that you cannot prevent everything. The crown gall incidence rate is too high and is across all USA small sellers. I didn't cut any flowers and I used a fresh razor blade for each clump when dividing. Previous to this, I have not had any gall on property despite having many plants susceptible to gall. Unfortunately, by process of elimination, I believe I introduced gall most likely in the dirt I bought to fill my pots with. Crazy right? The thing I did to prevent spreading gall to my yard is what brought gall to my yard. It was an important lesson in trusting my gut as well. The load of 'quality compost' I got came with weeds that looked virused. I was nervous about using the dirt, but, that 'sunk cost fallacy' kicked in and I used it anyways because I'd already paid for it. 

The virus came from one seller in particular, you can see the spiral virus marks on the leaves of her plants in her flower photos- so that's on me for not looking closer because you can see the concentric circles on the leaves in her photos. All the virus was her plants and then one that was near her plants. 

I've been struggling with how to get rid of 130 pots of dirt. If I throw them away, they will end up in the compost that goes out to other people's gardens. Because all of these were grouped at the lowest point in my yard, I've decided to put a couple raised beds there and fill them with this dirt and use it for bearded irises. I will put down weed barrier and use an herbicide to kill all adjacent weeds and create a 48" barrier around the whole bed. Irises are allegedly not susceptible to crown gall and I happen to like them. Fortunately, only thing near enough to be harmed is one grape vine, so if that develops gall I will remove it. So long as I keep weeds away, in a few years the crown gall should be gone with no viable host.

So yeah, that's the story of how I ruined my dahlias by trying to protect my garden and buying dirt from the wrong place. 

I'm not sure yet what I'm doing with the remaining 80-ish dahlias. I'm sure many more will show signs of crown gall during waking. However, the bad dirt wasn't used for all pots. At some point I ran out of that dirt, unfortunately, I didn't keep track of what pots got what dirt. From now on, that will be another thing I track. I may discard most of the remaining only keeping a few really nice ones. Most of what I bought last year were bargain tubers- most varieties are readily available. Unfortunately, my best ones are already lost to gall- so there may end up being only a small handful that get retained. 

This year I will be purchasing branded, bagged soil. It's unfortunate, I'd rather buy local, but local has proven unreliable. The load I bought before this one was herbicide contaminated and the load I bought after this one of 'top soil' is just screened clay. I think I will spend time sourcing pine fines and similar lumber byproducts to hopefully make my own compost pile so that I just make my own soil.