05/29/2026
TENT CATERPILLARS IN ALBERTA!
DON’T PANIC, WE’VE GOT THIS!
We had to do a little research ourselves… because wow, the sheer number of these little black wigglers and how fast they can strip a tree is shocking when you first see it.
If your trees (or even your house!) are looking a bit webbed over this spring, trust us, you’re not alone. Alberta is in the middle of a tent caterpillar boom, and while it looks dramatic, it’s actually a normal part of nature’s rhythm.
Why it’s happening:
Tent caterpillars follow a natural population cycle every 8–10 years, and this spring just happens to be one of those peak years.
How long it will last:
The good news: this phase is short‑lived.
They’re usually done feeding by late June, then they cocoon and disappear. Most trees push out fresh new leaves afterward and recover beautifully, even if they look rough right now.
What you can do (simple + effective):
• Remove the tents early in the morning when the caterpillars are inside.
• Blast them with a strong spray of water to knock them off branches.
• Mix Dawn dish soap + water in a spray bottle and apply directly to clusters, it’s surprisingly effective and avoids harsh chemicals.
• Let the birds help, robins, chickadees, and blackbirds think this is an all‑you‑can‑eat buffet.
• Skip the heavy pesticides if you can, nature usually balances this out on its own.
We used the Dawn dish soap mix in a big pump sprayer today, and it worked really well for us here at the ranch.
You can also sprinkle diatomaceous earth along pathways from trees to buildings (they crawl from tree to tree), just keep in mind it can affect other small insects too.
If you see them on buildings:
Totally harmless. They won’t damage siding, paint, or structures, they’re just wandering around looking for a place to cocoon. Yet we don't recommend squishing them against light colored siding and stuco as they can stain your house!
The positive side:
As messy as they seem, tent caterpillars are an important food source for birds and wildlife. The trees? They’re tougher than they look. Most bounce back with fresh green growth once the caterpillars move on.
So if your yard looks a little wild like ours right now, don’t stress, it’s just Alberta doing its spring thing.
The webs will be gone soon, and the summer greens will return.
Hang in there, prettier branches are on the way and we hope this post gives you some peace of mind!