Money doesn’t grow on trees, but protecting street trees in an urban environment can save homeowners money, and save the city money, all while offering health benefits to humans. Unfortunately, cities are terrible places for trees to survive, so while a feral tree* can take care of itself in the woods, you might want to consider offering your street trees some care back for all the good they do you.
Some of the benefits of trees are pretty obvious, but others might surprise you. Street trees take in carbon dioxide and offer us oxygen back. They offer us shade in the summer. They also cool the air around them when they emit a fine, invisible mist of water from their leaves through the process of evapotranspiration. All of that shade is not only nice on a hot day, it can lower you cooling bill in the summer. And, on top of all of that, the light colored leaves in the canopy reflect light rays away from pavement, which can hold heat, meaning that trees with larger canopy can also keep the pavement cooler for longer. Trees can also remove particulate pollutants from the air and keep them out of your lungs, and can not only absorb storm water, but hold it on its leaves long enough to reduce the burden on a city’s sewer systems, which can in turn prevent or mitigate combined sewer overflow and protect our waterways too.
If you want to put a value on it, you can! Using the tree value calculator you can actually figure out how much money you’re saving by protecting your tree, which is great if you’re economic minded, or if you’re trying to convince a business or your apartment building super to help your trees grow bigger. remember, like any young, living thing, young trees need more help than their older counterparts, and that help has to come from us.
There’s a lot you can do for your trees, but here’s a list of 10 pretty simple things you can do:
- Water them! That hot cement covering their roots is not only very hot, its limiting how much water the tree can get when it rains. If you can’t get a hose our carry a can out to them, empty your water bottles into them as you pass. Trees need about 15-20 gallons of water a week to survive, but every drop counts.
- Pick up the trash! Litter can harm trees, especially things like broken glass or cigarette butts. Not to mention, your neighborhood will just look better when the tree beds are clean. This also means that when you can, try not to stack your trash bags against the tree. And, while rocks are ok to leave in the soil, large chunks of broken cement can break down when it rains, making the soil too basic (trees tend to like slightly acidic soil), so try to remove large chunks of broken cement.
- De-compact the soil! You know those three pronged hand tools gardeners use? Cultivators? Use one of those to break up the soil! Most of a tree’s roots are actually hair fine and found in the first three inches of soil. Those roots are used to absorb water and nutrients, while the larger ones are for structure. However, if the soil is too hard, and it probably is in the city, the roots can’t grow out and water can’t get into the soil. By breaking it up, you allow the tree to eat.
- Stop walking on the soil! That’s one of the many ways that soil gets compacted in cities. Try to keep to the pavement as much as you can.
- Don’t let your dog pee on the tree! Its really common to believe that that’s what dogs do, or that its a natural fertilizer, but that’s simply not true! First, dog urine is made of acids and salts, which can literally burn a tree’s roots and trunk. Second, dog feces carries pathogens that both humans and other dogs can catch, which is really super gross. Its also made up of different things than, say, cow or horse poo, which is good manure, because cows and horses have very different diets than dogs. Even then, that poo is treated to kill bacteria before its used. Lastly, while a wolf in the wild will pee on a tree, that’s a few wolves in a whole forest over a lot of time, and not 100 dogs on one tree every day, several times a day. Even if you’re not worried about the tree, there’s a smell to the dirt that’s just horrible. Let your dog pee on the cement where it can wash away with the rain, and please always pick up their poo.
- Don’t let people hurt the tree! You can’t account for everyone, but reminding kids not to rip branches or carve things into the tree will help, and so will stopping people from taping things to the tree, or stapling the tree. Opening the bark up invited infection, which can at best rob the tree of valuable resources, and at worst invite infection and kill it. Trees may look monolithic and powerful, but they’re living things too! And yes, even tape wrapped around the tree is bad. That can cause “girdling”, which essentially strangles the tree and can kill it. Also, the tape traps moisture, which can cause rot. Tape signs to lamp posts or telephone poles instead!
- Plant flowers! First, when a tree bed has pretty flowers, people are way less likely to walk on the soil or litter there. Second, the flowers will wilt before the tree and remind you to water it. Third, flowers attract pollinators, which will also benefit the tree!
- Put up a tree guard! Tree guards keep people, dogs, and car doors out of the tree’s space and limit the number of hazards a tree has to face every day. A proper tree guard leaves room for water while creating an exclusion zone for people and dogs, even if its only largely psychological. I can’t speak to regulations everywhere, but you can usually either buy one (for a bunch of money) or get a permit to build one yourself for pretty cheap. You might want to get businesses in an area or apartment buildings to chip in for this, or apply for grants from local city council members, because it counts as neighborhood beautification and will do great things for your property values too.
- Apply mulch! Mulch helps stabilize the soil’s temperature and water levels, and keeps trash and pee off of the soil. Just remember to keep the mulch between one and three inches deep, and in a ring at least three inches away from the trunk of the tree, to prevent moisture from building up on the trunk of the tree and rotting it out. I don’t care how good that volcano of mulch is supposed to look, it’ll kill a tree. Also note that if you have to choose between mulch and compost, properly applied mulch is best, but if you can do both, that’s amazing.
- Get other people involved! Make signs, talk to your neighbors, get school kids involved. If you can do one of these things, its a huge help, but if you can get other people to do some of these, you stand a real chance of helping a young tree survive into adulthood.
Remember: the best time to plant a tree is 20 years ago, but the second best time is now. By protecting trees in cities (and heck, the suburbs too!), you help not only yourself, but your neighbors for generations to come.
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*That’s a technical term I swear.
I just want to add that there’s this pervasive myth that trees roots go straight down and are as deep as the tree is tall. Developers like this myth because it allows them to pave almost right up to the trunk, but then the trees die. As stated earlier in this post, their roots are mostly in the first couple inches on the top of soil. And these roots will want to spread even further out than their own canopies! They’re missing out on a ton of water and watering at the trunk may not be enough at a point.
Make sure you also advocate for tree-friendly paving practices in your city, such as permeable pavement or the use of special growing media underground and under the road and sidewalks for the trees.
A Guide to Street Tree Care
Published
Water Witches 