Blue Stain Pine: Beetle Kill Is Not Bad Wood

Blue pine, blue stain, beetle kill and denim pine are all names for the same wood. A beetle gets into the tree and carries a fungus in with it, and the fungus stains the wood. The color runs mostly blue, but it also shows up in oranges, pinks, purples, reds and a yellow that looks like the tree really needed to drink more water.

Is blue stain pine strong?

The most common thing people get wrong about blue pine is assuming the stain makes it weak. It does not. A study cited by the Colorado Wood Utilization and Marketing Program found no significant difference in stiffness or breaking strength between stained and clean pine, and only about 5% less impact resistance, which is of no practical significance in construction. The USDA Wood Handbook agrees that stain only slightly affects strength, and the stain fungi do not cause rot. It is just color, and we think it is really cool.

One practical note: stained wood can soak up more glue, paint or finish, so test your finish on a scrap first.

What to expect from us

Right now most of our pine logs have a chance of some blue in them, so if you order pine, expect to see some. If you want it, tell us and we will lean into it. If you do not, tell us that too. We usually have blue pine in the yard.

Why we cut it

The mountain pine beetle is killing our pine. The Colorado State Forest Service’s 2025 report shows it expanding again, with ongoing activity in southwest Colorado and Gunnison County lodgepole. We are losing those trees either way. They can rot in the woods, or they can become your siding, and we would much rather they become your siding.