I'm curious about the effectiveness of biodegradable tree protection guards. I've seen the light green ones everywhere, placed by eager groups planting tree saplings, but they seem to stick around for 4+ years. Is there any evidence that these guards genuinely degrade over time? Also, is there a standard definition of what 'biodegradable' means? ? On top of that, I've noticed they seem to only protect against certain animals; for instance, deer can easily debark hazel trees up to about 1-1.5 meters high.
3 Answers
From what I've experienced, biodegradable guards tend to crack into small to medium pieces, making them a pain to remove later. They can actually end up being more expensive than the plants themselves when you factor in the cost of support canes! Honestly, I suggest just planting more trees to account for any losses and skipping the guards altogether.
They biodegrade only under certain conditions, which I learned the hard way. My mother-in-law used them about four years back, and honestly, neither her biodegradable ones nor the non-biodegradable ones worked well. They both become brittle and fall apart eventually. In my case, I reused some past their prime, which probably contributed to the issue. Also, while they offered protection from deer in the first couple of years, I had to stack them higher after that, which isn't ideal for the trees. Plus, watch out for ants—they love nesting inside the spiral guards and stressing out the trees!
This is something that’s being actively researched. You can check out resources for alternatives to conventional plastic tree shelters. The standard biodegradable ones often linger for years. There are cardboard options that hold up just as you’d expect cardboard to in wind and rain, but ideally, they’d be collected after the trees are established—but that rarely happens! It's a bit disheartening to see them left behind as litter.