Tree Pit Tier List

Tree pits are small patches of earth on sidewalks in urban and suburban areas. Some people find street trees to be a nuisance because they take up sidewalk space, people frequently leave trash and dog droppings in them, and birds sit in the trees and rain droppings onto cars parked beneath them. Although those are valid reasons to not like street trees, the positive benefits heavily outweigh the negative.

Street trees are the only type of public infrastructure that increase in value over time as they get larger. The most important service street trees provide is shade from the sun. That’s why groups that manage street trees are typically called shade tree commissions. There are many other benefits for humans that street trees provide. Street trees also provide much-needed benefits for the ecosystems in urban areas.

Tree pit maintenance has similar regulations as sidewalks do. It’s the property owner’s responsibility to maintain street trees adjacent to their property. Because of this, tree pits come in all shapes and sizes. However, there are good and bad practices when it comes to tree pit design. Trees take decades to mature so it is a huge time commitment to let street trees grow. Street trees are also a large investment. Street trees are usually grown on tree farms until they are about 10 feet tall and then they are sold for around $200 to $400 each. Poor-quality tree pits jeopardize having good shade trees grow in them. If you’re looking for best practices for all things tree pits, refer to the NYC Park & Rec installation guide and maintenance guide. I have compiled a list of all the different types of tree pits I could find in Jersey City and Hoboken, two densely populated urban areas. I ranked the tree pits based on the long-term benefit to the tree growing within them. Let's start with the worst ones:

F tier

Having the pavers tightly wedged directly onto the tree girdles it and leads to an early death. This Callery Pear has already died because of this.

Same problem as the last one except with metal grates

The tree pit is too small for the tree. Because of this the roots have become bound together which will eventually result in the tree strangling itself. For best practice, the minimum size for a tree pit is 5'x10', but the bigger the better.

The same problem with the last one, the tree pit is way too small and will doom this tree as it grows. The tree guard is nice and tall to protect from dogs and is made of good sturdy material to prevent damage from cars.

Raised beds are not good for tree pits because it covers the root flare with soil. The root flare is the part of the tree where the trunk becomes roots and occurs at ground level. When you cover the root flare, making it lose its bark, you leave the tree more susceptible to disease. Another similar problem is putting too much mulch up against the trunk of the tree creating a “mulch volcano”

Not sure what they were trying to accomplish with this tree guard. It’s like putting a tree in an iron maiden.

C tier

Hard, compacted soil is not good for allowing oxygen to reach the root system

This tree pit is 3'x3' which is not the worst I’ve seen, but still too small

These pavers are not completely compacted so the tree may be able to push them out as it grows.

This property owner really didn’t want anyone leaving trash or dog droppings in their tree pit. Although this looks nice, it will hinder the tree on the top once the tree gets bigger. It’s also only 3'x3'.

B tier

The tree pit is pretty a decent size and the property owner is removing bricks as the tree grows

Decent size and has a nice tree guard although it would be really annoying to open your door if you parked in front of it. The best tree guards are tall on the sidewalk side and low on the street side so people can open their car doors.

This tree pit has a shallow barrier that helps keep the mulch from floating away during heavy rains.

A tier

This tree pit has it all. 10'x5' area, nicely mulched, a strong metal tree guard that is only three-sided to not hit car doors.

The best tree pits are the ones that take up the entire length of the sidewalk. This also enables other smaller plants to grow in them as well.

Special Mention

This one is from the Netherlands I believe based on the license plate. I think it’s cool because I’m a skateboarder and this would be really fun to ride. The tree is too young to determine if the design will work for a healthy tree but I have a feeling it will not. They either buried the root flare at the ground level which is not healthy. Or if the tree was planted at the top of the pit, the roots will probably become bound.

This isn’t really the same as the others because it’s more of a road median than a tree pit. However, maybe someday these types of plantings can replace residential sideroads in urban and suburban areas.