NYC is counting its trees again (and you can help) 🌳
Free swag you’ll score when you join a training event. Sign up info: https://www.nycgovparks.org/reg/trees-count
Did you know New York City does a tree census every ten years? Yep, like people, but leafier.
The tradition started back in 1995, and thanks to these once-a-decade headcounts, we know there are 883,267 trees across 541 species standing tall in NYC today. The most common? The London planetree—basically the overachiever of our sidewalks—making up almost 10% of the city’s canopy.
All of this data feeds into the New York City Tree Map, where anyone can explore the living infrastructure that shades our sidewalks and cleans our air.
Who counts the trees?
NYC Parks splits trees into three groups:
Street trees – the ones lining sidewalks.
Park trees – hanging out in playgrounds, picnic lawns, and sports fields.
Forest trees – the city’s wilder cousins in woodlands, monitored by rangers.
With each decade, the canopy expands—and so does the challenge of measuring it. Luckily, the tools keep evolving too.
This year, Parks staff are rolling out the cool gadgets: cars with LiDAR scanners (fancy lasers that make 3D maps) will zoom around and survey the street trees. The data will get crunched by machine learning, so those trees are covered. (See previous report on LiDAR usage for scanning the street trees)
But park trees still need humans. That’s where you and I come in—with tape measures, tree ID guides, and a smartphone app.
Meet the tree ID guide
Leaf shapes are grouped into “Teardrop”, “Spade”, “Uneven”… and so on.
The guide is basically a cheat sheet for tree nerds-in-training. The cover shows the 24 most common NYC park species. Inside, trees are grouped by leaf shape, with quick “how to tell me apart” tips. Honestly, it’s fun to flip through even when you’re not volunteering—it makes walks feel like mini scavenger hunts.
How to play tree doctor
Once you sign up, you’ll get access to a Parks map on your phone (built on ArcGIS if you’re into the tech side). You’ll pick a dot (a.k.a. a tree), and record what you see: trunk sturdy or cracked, leaves healthy or chewed, any pests or funky fungi in sight.
Staff showing how to assess health
Thanks to past censuses, the city already has GPS points for nearly every tree. Your job is to check up on their condition. It’s strangely addictive—kind of like Pokémon Go, but instead of catching Pikachu, you’re befriending maples and oaks.
🌱 Wanna help count NYC’s trees?
Join a training session, snag some swag, and give your neighborhood trees a little love. 👉 NYC Parks Training Registration
