If you've been following the last few updates, you'll know that we've been feeling better about our orchard operations this year compared to last.
- We got all the replants planted in the winter.
- We terminated the cover crop earlier than in 2025 to make nutrients available for the trees and reduce vole habitat.
- We added an additional drip emitter per tree and providing more consistent irrigation.
- Our tissue samples in May were generally in line with the benchmarks for healthy trees.
All good improvements year over year.... that is, until we started taking the wraps off for a second round of suckering in late-July. Below are a few images of what we found on more than 500 trees.
Voles, which were pushed into the tree row when we terminated the cover crop, took refuge from the hawks and owls inside tree wraps and severely girdled more than half our trees. This quickly killed dozens of our replants and has put many of our 2-year-old trees on the course towards death.
How many exactly will die? We don't know, as most of the large trees' canopies are still alive.
Their roots are still feeding the leaves water, but the roots are not getting any sugars back from the leaves (sugar is transmitted from the leaves down to the roots via the cambium). Our expectation is that many of the trees with strong-looking canopies now, will die next year when their roots starve.
The videos below show two extremes of what we're seeing. The first is a tree that was fully girdled 12" off the ground and has died. The second is a tree that was fully girdled and it's canopy is thriving. It's hard to believe this second tree will suffer the fate of the first, but that is the most likely case.
There is (some) hope. Many of the trees with the most severe vole damage have pushed suckers, which can feed sugars to the roots to keep them alive while the girdling heals. Others, like the one in the first video above, have failed canopies, are also pushing suckers. Since our trees are self-rooted, suckers are the same cultivar as the failed canopy. We're leaving the suckers alone in both cases to support the roots and/or become the new tree.
Another group of the damaged trees have not yet pushed suckers, but are healing their cambium much faster than "the book" says is possible. Most folks we've talked to and internet researching we've done about the girdling suggests that cambium can only repair at a rate <0.5" per growing season. We're seeing >100 of the girdled trees with at least 1" of cambium healing in the last 6 weeks.
Below are a couple examples of this rapid healing.
Will this rapid healing be enough to save all the trees? No. Will it save some, I sure hope so. It has been heartbreaking to see the amount of damage these trees have sustained, and watch ~12 foot tall trees collapse in a matter of weeks. We'll take any sign of hope we can get.
Late Summer Tissue Samples
We took a second set of tissue samples in August and compared them to both the May samples and the chestnut benchmarks. Below is the summary of the samples and the comparison.
Not terrible, but we have some work to do, especially on N, P, and K.
The big caveat is that these August samples are from trees that have been severely stresses by rodents eating their bark and roots since June. It's likely that the nutrients the trees need are in the soil. They're just too damaged to access them. Our plan is to apply the trees all the water they need to give the best chance of healing as possible and then take...
Soil Samples!
We took soil samples the first week of September, using a blend of soil from a number of spots on our farm and varying depths. The goal was to get a representative "average" sample of the soil approximately 12 inches below the surface. Best practice would be multiple samples at multiple depths, but on a 13-acre orchard we felt okay with an average of the depth where the roots are mainly feeding.
Below are the results of the samples compared to the published targets for chestnuts and soil samples from the native soils within a mile of our orchard (taken at the same time).
I'm glad to see the pH is still in a good spot and soil P and K are OK. This soil tests confirms what we'd expected - the August tissue samples looked deficient because the connection between the roots and the leaves had been broken by rodents. Not because the soil was deficient.
Our focus on building soil health through compost, biochar, cover crops, and mulch still seems like the right plan. That will get the organic matter up and add lots of NPK + some calcium. Maybe we'll add some copper if it remains low in the tissue samples next year.
A Bright Spot
The vole damage this year has been very discouraging. It's been hard to find good news in the orchard when so many trees are so damaged. One small bright spot is that several of the Okei chestnut trees we planted this past winter as <6" tall liners have grown 5 feet or more and are flowering. The photo below is of one such tree in August.
August flowers aren't going to get us a crop, but it's good to see that these trees grow vigorously on our farm and are maturing with the potential to cross pollinate with the Colossal next spring.