TikTok is telling you to ‘leave the leaves,’ so we asked a Utah horticulturist about it
The yard work adverse among us probably doesn’t have to be told twice. But what about the perfect lawn obsessives?
“There's a lot of psychology, a lot of really deep, almost even genetic, connection to that landscape around us,” said Sheriden Hansen, a Utah State University horticulture professor. “We want to see green, grassy areas because that grass is a safe space. We can see far out from our home and make sure that it's safe.”
Mastery of your domain is deep-seated in American neighborhoods “because if you had a landscape, that meant that you had wealth and status. It sets up what people think about us when they walk into our homes.”
If you can fight the urge to break out the leaf blower though, leaving the leaves is a great way to improve the soil and help beneficial insects. Thanks to the circle of life, of course.
“As they break down, they increase the health of our soil by adding this thing called organic matter,” Hansen said. “It's like the magic bullet.”
Organic matter improves drainage and airflow in the soil. And that’s extra important for Utah, she explained, because the state’s dirt is low on organic matter due to the state’s arid environment.
It is not, however, as simple as the plant lady on TikTok might make it seem. There’s always a catch.
Don’t “just leave a huge layer of leaf litter,” Hansen said, it’ll eventually kill the turf. Instead, she suggested leaving a light layer and mowing over it to mulch the leaves in place.
“They will break down much faster over the winter, and you can have the benefit of that organic matter breaking down and moving into the soil where your turf is,” she said. “Building that healthy environment for turf to grow in.”
You can also move leaves to other parts of the yard, including flower beds. That way, insects like bumblebees can make their wintertime nests. Without native bees, pollination decreases.
“We are going to divert those leaves to these spaces where the earthworms can get to them, where some of the predatory beneficial insects can hide out and hang out,” Hansen said. “So that we have them available to us next spring.”
This interview has been edited for length and clarity.
Ciara Hulet: What’s the impact of sending leaves to the landfill, which is where people usually get rid of them?
Sheriden Hansen: It increases carbon waste. If we can break down that carbon and move it into the ground, that's part of that carbon sequestration. We don't want to be releasing carbon in a way that is not the best for the environment. If we will move leaves into areas of our yard where they can break down naturally with the microorganisms, that will help with the emissions.
And [not sending leaves to landfill] helps with the overall amount of waste that we send away from our homes. If we can keep that on site, that waste is useful waste, it's not really waste.
CH: Is there a difference in how leaves break down in our yards versus a landfill?
SH: If you're sending leaves to the landfill, you're putting them in a plastic bag. That is going to be buried deep into the soil. It's not going to have microbial activity. The plastic around the leaves is going to have to break down from that bag as well.
Put it in the yard where you have the microbial activity, there's the airflow, there’s sunlight because we're not burying it deep in the ground. It's not surrounded by plastic. It's going to break down naturally and move through the soil.
If you don't want [the leaves] in your yard, you can definitely take it to a landfill that takes green waste, and they can turn that into compost. I know that there are a few landfills around that will do that.
CH: So is there a situation where it's better to bag up leaves?
SH: I have a lot of neighbors that have scrub oak, and they drop a lot of leaves late in the season. They can gum up that storm drain system. We want to definitely get those leaves out of those areas. You can simply move those to your beds. If you have a compost bin and you don't want to add it to your beds, add it to your compost bin; that's another great place to put it. If you have to bag up sections of it, that's fine.
The other time we would want to bag up some of these leaves is if we have a tree that is dropping leaves that have been diseased over the course of the summer.
CH: What about dealing with neighbors or HOAs who might be upset that we’re not raking and bagging like everybody else?
SH: Tell your neighbors to relax and educate them with a smile. We don't want to fight with our neighbors or our HOAs. We just want them to know why. This is where cleaning up certain areas of your yard, like doing a mow over your turf and moving those leaves to areas where they can stay so it doesn't look so unsightly will definitely help to ease that tension a little bit.