Buckeye seedlings turned brown and died, why?
I collected several dozen buckeyes last fall, and stored them in a bag of soil in an unheated garage over the winter. Come spring, they were happily sending out nice long roots.
I decided to use them for an experiment. At my job, we have heavy cardboard tubes left over at the end of the day, approximately 5" in diameter, 1/2" thick walls and 16" long. I sunk these into the ground 4-5", filled with compost, and planted the seeds into these to see how they would perform as free tree pots for tap-rooting trees.
The tubes look like the link below.
At first, the seedlings grew very well. Starting in mid-June, however, the leave edges started to turn brown and die. Eventually all the leaves turned brown/yellow and the plants died.
Upon "dissection", the seedlings' roots looked large and healthy, and the soil was a little on the dry side. We've been having a record year here in Minnesota for rain, so I never bothered to water them.
So, either a blight of some sort attacked all of them, a chemical in the tubes killed them, or the cardboard wicked away enough moisture to kill them. I'm not upset, as I have nowhere I wish to plant a buckeye anyway, but I DO want a plausible answer before I start trying to grow species I really do care about.
Anyone want to help me play CSI: Buckeye with me here and chime in?
Here is a link that might be useful: