One of the main trials we're conducting in our orchard is all about tree tubes. What sizes are best for our climate and pests? Do colors matter? What about stakes? etc. Here, we share all that we've learned so far and what that means for future plantings.
As usual, we're going to focus on all the things we did wrong or problems we're having. It's easy to get folks to talk about what's going well... It's also not super helpful to learn from. We're all about sharing what we're screwing up so others don't make the same mistake. Let's dive into some problems!
1. Voles
Of the ~900 tissue culture chestnuts we planted in January, we'd only lost 2 as of the middle of May. Those 2 died due to heat stress and plug irrigation emitters. Since then, we've lost ~25 more due to voles eating the trees roots.
The type, size, & color of tube doesn't seem to be impacting which trees they go after as much as the amount of weed cover that is available for them to get close to the trees. The rockier spots of the farm seem to have the worst vole pressure and I think that is becuase the voles like to burrow under the boulders and our radish cover crop was largest there. We've only seen a few trees where a rodent climbed up the tree in the tube and ate the bark/leaves.
The vast majority of the dead trees look like the pictures below, with their roots eaten off a few inches below the ground. It is VERY frustrating to see a healthy tree that has grown 4-6 feet in just a couple months get killed by rodents!
2. Wind
Most days, the orchard receives constant winds from the Southwest. It's not uncommon for them to reach 20 MPH or faster multiple days in a row. We knew it was a windy spot, so we selected flexible stakes: #3 rebar and Plantra's trunk builder stakes. These stakes seem to be doing an OK job getting the trees to thicken up their trunks while they were pushing up through the tube.
The image below shows a tree with a 5-foot tube removed taken on June 2nd. A couple things to callout in the picture:
a. The tree is flexible, but is still able to hold itself up without the tube
b. The tree has grown more than 4 feet in the 8 weeks since breaking dormancy the first week of May. It was planted bare root in January 2025 and my finger in the image shows the start of this year's growth.
c. There is some branching on the part of the tree that is inside the tube, especially near the top.
So, that all seems like it is working. The problems began to arise as the trees added a few more feet of growth in June and July and extended past the top of the tubes.
As the some of the trees grew beyond the tubes, they.... Grew at a severe angle...
Or, their tops broke off.
Not good.
Those that had the tops broken off, quickly sprouted a bunch of new branches and began pushing a new leader (see the picture below). So, we're now going through the orchard and pruning, or at least pinching off the leader tip, of trees that are leaning too far out the top (second and third images below).
This problem of wind leaning at the top of the tube is worse on trees in the taller tubes. Those in the 2-foot, 3-foot, and even 4-foot tubes are better able to resist the constant wind pressure when they push out of their tube (see pictures below of trees in 3-foot tubes). These trees are also several feet shorter than those grown in the 5- and 6-foot tubes, but we're not trying to grow tall trees, we're trying to grow productive ones.
One other trick we're trying to help overcome the wind-lean, is removing the top 2 feet of tube on some of our trees in 6-foot Plantra tubes and then doing a couple of heading cuts to encourage branching at 6-7 feet. Below is what these trees look like with the top 2 feet of tube removed before and after the pruning cuts.
It's hard to remove so much healthy growth in the middle of summer, but we're concerned that if we don't take action now, the trees will require an even more drastic intervention later on.
3. Suckers
The majority of our trees have a substantial number of suckers. I don't have specific evidence for this, but my sense is that the suckers really started pushing when the top of the trees pushed out of the tubes and felt the stress of the wind.
Some of the suckers are finding holes in the tubes to push through, like in the picture below. Most are bound up in the tube.
I'm not sure what we're going to do about the suckers. The trees are far too big to remove the tubes over the top this winter, but I need to remove the suckers. I suspect I'll have to cut each of the tubes off, remove the suckers, then replace the tube.
Tube conclusions halfway through the first year...
I'll share more about what we learn about the tubes, how the heading cuts work (or don't), etc. later on. Based on what we've seen so far, if I had to choose a single tube for a new planting, I would like go with a 3-foot tall removable tube that doesn't allow light penetration.
Why that style of tube? We have basically 0 deer pressure so I don't need to protect the trees against browsing. The trees can easily grow 5 or more feet in a year in our climate, so I don't feel the need for a large greenhouse effect to accelerate growth. I'd like the first lateral branches to start around 3 feet of the ground to facilitate machinery getting close to the trees. And, we're seeing way more suckering that we expected, so a tube that blocks the light should help reduce sucker growth.
By the way, a huge shoutout goes to Steve at Plantra. He has been a major source of advice for how to use the tubes, adjust them based on the issues we're encountering, brainstorm pruning methods, has visited our orchard multiple times this year, and received countless pictures/text/etc. from me seeking his input. Thank you Steve!
If you made it this far, you're a real chestnut masochist. So, here's some glamour shots of good looking trees for your enjoyment.
