Happy New Year fellow chestnut farmers!
It's pretty wild to think that just 1 year ago, we were watching our trees push their first leaves in their permanent home. As I write this it is the last few days of February and we're starting to see the first signs of dormancy breaking. A very exciting time of the year.
This update covers the main winter projects we've been working on since our Fall 2025 Year 1 Lessons Learned post. If you haven't read that, it's probably best to start there as much of what we cover below is building upon what we learned in 2025.
Irrigation Infrastructure
One of the main projects this off season has been overhauling our irrigation system. Last year, we struggled to give the trees enough water due to a well being offline, filters clogging, and only having 1 emitter per tree. Thankfully, we got the well working before peak season last year. The other issues we addressed this winter in a couple of ways.
The first is a total rebuild of the irrigation manifold and filter system. This included adding a manual main valve as a backup in case the electric one fails (like it did last year), replacing the 4x 2" filters (one for each zone) with one 3" filter for all zones, and building an in-ground box to house the whole thing. We'll add a living roof as shade soon. Below is an image of the improved setup as well as a video of all 4x zones running with consistent PSI.
The second, was adding another emitter per tree. Each tree now has a 1 GPH emitter two feet to either side of its trunk. This doubles the amount of water the system delivers per hour and increases the wetting pattern around the trees - encouraging further root growth. It also moves the wet spot away from the base of the tree, which we think contributed to all the vole damage we had last year. The voles were digging for water as much as they were for roots.
Replants & Pollinator Cultivars
129 trees died last year. We needed to replace all of these, as well as add in a few more. The breakdown of the winter planting is:
129 TC Colossal Replants, 35 TC Colossals in a new row, and 146 TC Okeis in 5x rows as pollinators. The Okeis are very small (images below). It's nerve racking putting them in the ground so small, but they had pretty good roots started and we're in a very mild winter climate, so fingers crossed they'll take right off.
That second tree has two tiny leaders. We'll remove the weaker one as soon as the primary starts growing in the spring.
Suckering and Tree Tube Adjustments
Every tree needed its suckers removed. This meant taking off each tree tube removing the weeds and suckers and then putting the tube back on. Below is what the trees looked like when we first took the Plantra Tree tubes off.
One of the things we learned last year was that we don't have deer issues and so don't need tall tubes. Instead of putting the tubes back on as they were, we shortened all the tubes that were taller than 3 feet down to ~3 feet. This will continue to protect the base of the trees from weed eating and mowing, but will let the trees branch starting at 3-4 feet off the ground.
Pruning
Speaking of branching, winter is the time to set (or reset) the tree's structure through pruning.
We spent a bunch of time last year walking the field, researching online, and talking to other growers about how best to prune our trees. What we settled on was a pretty aggressive heading cut on most trees. The next two images show a tree that has been suckered, its tube shortened, and then pruned.
It is painful to cut 5+ feet off of a tree. Frankly, we spent a fair bit of time researching chestnut pruning just to convince ourselves that there were better options than this deep heading cut. However, we decided to do this as the primary cut for several reasons.
- European x Japanese Hybrid chestnut trees are very tall, and we planted them on 20x20 foot spacing. The modified central leader structure seems to be the best option to maximize light coverage on each tree's canopy while at this relatively close spacing. It will continue to be a solid structure for the trees even decades down the road when we remove every other tree.
- The wind hits our farm almost every day from the same direction, the SW. Most of the trees were therefore leaning or curved by the wind. We made the head cut just above a healthy bud that is growing into the wind. This will increase the odds that the leader that emerges from that bud will grow vertically.
- We want a somewhat-consistent height of each tree's first scaffold - around 4 feet off the ground. That will give us enough clearance to mow/spray/sweep underneath the trees, but not so high that we can't prune for 1-2 more years as we set the trees' shape. If we didn't do a head cut on the really tall trees, they would push their first set of branches between 7 and 10 feet off the ground. Branches that high would be difficult prune next winter and shade out the buds lower on the tree.
In addition to the main heading cut, we removed branches that had an acute insertion angle in to the central leader as well as those that we're damaged or below 4 feet off the ground.
The image below is a close up of how we pruned branches that were at the right height for the first scaffold (between 4 and 7 feet off the ground), but were growing too vertically. The flat cut and leaving a lateral facing bud or two should increase the chance that those lateral buds will push this spring and turn into solid fruiting branches next year.
There are two rows that are the exception to the above-mentioned pruning method. The first is the row that had 2-foot tall blue tree protectors instead of Plantra Tubes. This row is planted at 10-foot in row spacing and, as you can see below, without any pruning the trees chose an "Open V" shape. Instead of trying to get these trees into a central leader shape, we only removed low and crossing branches. We're calling this row the "U-Pick Row" as it will likely be a low-to-the-ground hedge in a year or two. That'll be tough to operate machinery under.
This row will also be an interesting test to see if less pruning results in fewer years until a first crop. My gut is that less pruning does increase speed to chestnut production and this row will provide evidence one way or the other.
The other row that we pruned differently is the row adjacent to the blue U-Pick Row. It is one of the 4x rows that are on 10-foot in row spacings with 3-foot Plantra Tree tubes.
On this row, we pruned every other tree into an Open V shape, with the balance the same as the rest of the farm - modified central leader. This is to test pruning a high-density row into a permanent tree (the modified central leader one) and a temporary tree (the Open V one) to maximize nut production in the first few years without negatively impacting the long-term structure of the permanent tree.
In other words, prune the permanent trees like you want them to be permanently, and keep the double density ones in their shadow. The short ones will likely never be as productive as the tall ones, but that's OK becuase their role is to increase production for the first 5-10 years until they're fully shaded out.
Owl Box
One of the biggest problems last year was rodents killing our trees. We had a few hawk posts up and frequently saw raptors resting on them, but this year we're upping our game by both terminating the cover crop earlier than last year (scroll back up and you'll see that we weed-eated the berms in February) and attracting barn owls.
Our neighbor is skilled at a whole number of trades (e.g. he built his own house!) and offered to build an owl box instead of us buying one. I thought I was a great idea and a few weeks later he sent me a picture of the box below.
I had no idea what a beautiful box he was going to make! It looks amazing and he even when as far as reaching out to non-profits focused on barn owl habitat to refine the design of the box before he built it.
We're grateful for his help and know that some family of owls is going to be spoiled. We don't mind, as long as they eat a few thousand rodents this year.