While it is true that you will read a little bit about an actual tree that grows in Brooklyn, don’t worry—this book isn't all about the tree and how it grows. Phew, right? That would be a total snoozer.
But if it’s not all about this literal tree, then what is up with the title? Well, the tree and Francie have quite a bit in common. The specific type of tree in the backyard is a very strong tree that can grow in even the worst conditions. It doesn’t really need much to thrive, and there have even been cases where this tree has grown up through concrete. It’s that tough.
Francie, our protagonist, loves this tree. Its leaves surround the fire escape, and Francie sits there and pretends like she is living in the tree. Francie is growing up in poverty, so poor that there are plenty of times when she doesn't get enough to eat. This is real deal poverty, and yet Francie thrives anyway… just like the tree. Mama even comes right out and compares her to the tree when Francie is a baby and people keep telling her that Francie is too weak to survive.
At the very end of the novel, we see the tree again. It was cut down a while ago because people thought it was a nuisance, and when Francie looks out the window she notices that another tree is growing right out of the stump. This darn tree refuses to be beaten—much like tenacious Francie. These two just never give up, and the title helps establish their similarities.
The new little tree sprouting from the trunk of the old one is now growing for Flossie and anyone else who lives in the neighborhood. The tree that grows in Brooklyn is there to inspire folks to bust through the challenges that come their way, to stand tall in the face of poverty and figure out a way to thrive too.