What should we do with the leaves in our yard?(Jeremy Thomas / Unsplash)This week on Science Behind the Forecast, what should you do with those leaves all over your lawn? LPM’s Bill Burton talks about it with meteorologist Tawana Andrew.This transcript was edited for clarity and length.This was originally broadcast in October of 2020.Tawana Andrew: Is fall your favorite season? I have to ask.Bill Burton: Fall is neck and neck with spring.TA: I'm with you there. The reason we call it fall is because leaves are falling, right?BB: It's a great season. I can't argue, and I'm enjoying it already.TA: The leaves are the thing that we're talking about. I've seen a few arguments on Facebook about this particular topic, so I figured I might as well jump into the fray and help out, so you're not arguing with your neighbor over this particular thing.BB: What do we need to know about the fall of leaves?TA: I know everyone's like, should I rake or should I not rake? Whether to make your neighbor happy or you don't want to do the work. Experts recommend mulching, not so much raking your leaves. You can use just a regular lawnmower with this, and make sure the discharge chute on the lawnmower is closed when you do this, because that can help to chop up the leaves pretty finely. That helps them decompose and return valuable nutrients back into the soil. By doing this, you're helping yourself later once you get into the spring because when you mulch the leaves, it basically acts as fertilizer. That helps your grass grow even better the following year, and mulching has been shown to help to suppress weeds. One study found that leaf mulch could reduce the amount of dandelions in a yard by up to 84% for the next season. That is less of you on your hands and knees in your yard trying to pull up some weeds.BB: 84% is a good number.TA: It's a pretty good number. We need to work on getting that a little bit higher, though.Here's the thing: you can't do the mulching when your yard is basically a blanket of leaves. It is recommended that you take that lawnmower and just go over your yard when the leaves are covering about 10 to 20% of the lawn. You should still be able to see the grass through the layer of leaves when you're doing this. Once you basically end up with that blanket of leaves, it's recommended that you remove about 25 to 50% of leaves by either raking or blowing, and then you mulch the rest.Too many leaves on your lawn actually can be very harmful. It can inhibit grass growth in the spring season, promote snow mold diseases, and even enhance damage from animals like mice during the spring.Also, I know a lot of people like to just blow the leaves out of their yard into the street because it's easier, but keep in mind that when these leaves break down in our sewer systems and other waterways, they can actually cause algae blooms. That is very dangerous for plants and animals that live nearby, and maybe even those kids that like to walk into those creeks. It's not a good idea to have that. It's very unsafe. So now that you know you know what's the safer and the easier alternative to deal with your leaves, maybe the Facebook arguments can calm down a little bit. ...read more read less