In designing and planting this garden, I selected 3-6 varieties from each of the 20 different dahlia forms, in order to teach people about the diversity of type in the dahlia family. My proposal to plant this garden on the Pybus property was considered and accepted by the Pybus team, and I went to work. First, I selected a spot, with the advice and guidance of those familiar with the master landscaping plan. The northeast corner of the market property, adjacent to the back parking lot, was chosen as the ideal spot - having good sun exposure, great drainage, good visibility for Market visitors, and nothing else planned for that area. I hired people to till the spot, and then I brought in topsoil/compost mix, as well as additional compost and soil building materials. I organized the layout of the space, and eventually planted about 118 tubers/plants in mid-April.
I watched as my garden grew, and I had a little bit of concern about the most northern part of the bed getting enough water. This was dealt with by increasing the automatic watering times, and by frequent hand watering that I did 3-4 times a week. I was thrilled and excited to watch my plants come up, and I have tended this little space with much anticipation. However, a few weeks into the growing season, I thought I started noticing some irregular foliage growth, a growth pattern that looked eerily familiar to me, and which I tried not to believe was happening. At some point during this time, I vaguely rememberd that I had seen one of those little flags that the lawn care companies put on your property when they treat your yard, but it wasn't exactly in the spot where I had the garden. So I kind of forgot about it. Denial worked for a while, until I finally couldn't ignore the nubby buds, the curled and leathery leaves, the distorted flowers that appeared on Kathy's Choice and Badger Twinkle - I finally had to admit that most of the plants in the garden were suffering from "herbicide carryover." Dahlias are particularly vulnerable to this condition. My first experience with it had been during the 2012 growing season, when I and my friend Mike used some manure from a local farmer to help enrich our soil. We didn't know that it contained remainders and residues of herbicides that had likely been used to kill grasses along the country highway where it originated. Our dahlias struggled mightily to grow out of it, but the result was a much reduced yield and lower quality blooms and plants for about half the season. Eventually, it seemed to be leached out of the soil by heavy watering and time, but it is not the kind of thing dahlia gardeners want to have to deal with.
I visited with several local garden/farm supply people yesterday, trying to brainstorm a solution for the problem, and they had a few ideas. After talking with them, I think I will try a combination of drenching/draining the soil and adding some compost tea that may help neutralize the soil through the growth of healthy microbes. The conditions don't seem as severe as they did in 2012, but there is no doubt that the early flower and foliage on my dahlias is anything but normal. The good news is that I only have this problem at Pybus, probably due to treatment of the area by herbicides, prior to the decision to plant the garden. I don't anticipate that it will happen again, if I continue to grow in that spot. Fortunately, it is early enough in the season that the chances of getting back to normal are pretty good - wish me luck!
Leathery, thickened and curly foliage is characteristic of herbicide carryover.
Nubby deformed buds are also common symptoms.