09/29/2026
Look at these fuzzy little hats! 🌰 These acorns came from a sawtooth oak (Quercus acutissima), and those shaggy, curly caps are its signature look.
There are 400 to 500 species of oak worldwide, with about 90 being native to the US. – the sawtooth oak isn’t one of them. It’s native to East Asia (China, Korea, Japan) and was brought here and planted widely as wildlife food because it drops acorns early and in big numbers. Spot it by its narrow, chestnut-like leaves and acorns with bristly “teeth” (where the name comes from).
It’s cute but… now it’s spreading into natural areas in parts of the Mid-Atlantic and Southeast, crowding out native trees. Deer and squirrels happily eat the acorns, but it doesn’t support our native insects the way local oaks do.
Why does that matter? Native oaks are keystone plants. They host more caterpillar species than any other tree in North America, and those caterpillars are what songbirds feed their babies. One native oak is basically a whole ecosystem. 🐛🐦
Best keystone oaks for us here on the Main Line and Southeastern PA:
🌳 White oak (Quercus alba): the gold standard, long lived and wildlife rich
🌳 Northern red oak (Q. rubra): fast growing with gorgeous fall color
🌳 Swamp white oak (Q. bicolor): tough, handles wet or compacted soil, great for yards
🌳 Pin oak (Q. palustris): classic street and yard tree, loves moist spots
🌳 Chestnut oak (Q. montana): perfect for dry, rocky sites
🌳 Willow oak (Q. phellos): narrow leaves, graceful shape, native to our Delaware Valley corner
🌳 Black oak (Q. velutina) and scarlet oak (Q. coccinea): great for drier, sunnier spots
Have space for a big tree? Plant an oak. Your grandkids’ birds will thank you. 💜
Check with your local township – many offer free tree planting in the fall – and request a native oak!
📸 Sawtooth oak acorn cap, leaves and cap, and leaves of a native pin oak 🍂
