JOAN CARTAN-HANSEN, HOST: Composting is the process of recycling organic materials so they can improve the soil.

It's a great way to reduce the amount of trash going into landfills and you may end up with something yummy to eat.

(Music) CARTAN-HANSEN: Humans get their nutrients by eating food, but plants get their nutrients from the soil, that helps them grow.

And that's where composting comes in.

LISA KNAPP, CITY OF BOISE COMPOSTING PROGRAM: So composting is really just taking a natural process that occurs in nature, which is the breakdown of all organic material.

So, if you think about when you're in a forest, you'll have trees and plants that fall over and you have that thick layer of humus that sits on the forest floor and it smells really good.

And that process that happens naturally, that's from bacteria and different microbiology breaking things down.

But that takes a long time.

That takes years for that to happen.

So, in composting, we are taking that same process and we're engineering it to make it happen much, much faster.

CARTAN-HANSEN: The compost people use for their gardens can come from a variety of products.

KNAPP: Anything that is organic, which means that something that was once alive.

So, if it was a fruit or vegetable, a tree, a plant, anything like that can be turned into compost.

Any fruits and vegetables that are in your kitchen, your apple core, your banana peels.

Just remember to take off those little stickers that are on the fruit.

So in addition to your grass and the things that come out of your yard almost anything that grows there, we can also take in wood.

So, things like a popsicle stick after you finish a popsicle can go in your compost bin.

Your chopsticks, if you were to go get sushi and bring that home, if you have those wood chopsticks, those can be composted.

CARTAN-HANSEN: Everything goes into a composter, a container designed to hold the waste while microorganisms do their thing.

It can be something small in a home garden or some composting is done at major facilities run by cities.

KNAPP: What happens first, our stuff comes in, it comes in on a garbage truck, just like you would see at a house.

And it gets put into the tipping area.

And at the tipping area, a person goes through it and they screen out what we call contamination, which would be anything like a plastic or things that were put in the wrong bin at someone's house.

So, we take that out and then the material is picked up and put through a tub grinder.

And that grinds up any kind of big thing, so woody debris.

So those branches or stumps or things that may come in, it'll break those down into really small spaces and what that does is it creates an environment for bacteria to grow.

CARTAN-HANSEN: The process takes time, water, and heat.

KNAPP: So, the goal is to get to 131 degrees Fahrenheit, which kills off pathogens or to get to 145 degrees, which kills off weeds.

Typically, in this kind of a big industrial facility, we reach temperatures easily of 155 to 160 degrees.

So we get way above that.

CARTAN-HANSEN: Over time, the organic waste is converted into a rich dark soil-like material called compost.

It has lots of nutrients and gets mixed into soil to provide food for plants.

KNAPP: So, all of us at our homes, we generate garbage, we generate waste.

And that waste has to go somewhere, so a lot of our waste will go to what's called the landfill, which is the place where the garbage truck takes most of our trash.

When we recycle or we compost or organic material.

We're keeping material out of the landfill, we're saving space.

CARTAN-HANSEN: And there is another good reason to compost food and lawn waste.

KNAPP: Like I said, all this organic material, when it goes to the landfill, it breaks down.

And over time it creates what's called methane, which will come out of our landfills for years and years when it's in there.

And that's a very, very toxic greenhouse gas that contributes to climate change.

CARTAN-HANSEN: And how can you compost?

To get started, pick a dry site that gets partial shade or use a specially designed composter box.

Add lawn clippings and kitchen scraps.

Don't add meat or bones, dairy products, oil or grease, baked goods, coffee pods or tea bags.

You can certainly add grass clippings, but avoid any diseased plants or material treated with pesticides.

And just like at the big city compost locations, gardeners need to turn the compost regularly and add water to keep it moist.

Monthly rotations help the compost develop.

Certain bugs, worms, and maggots in the composting bin can be a good sign.

It's nature's way of adding air to the compost as bugs move around the bin.

How long does it take to turn waste into compost?

It depends on lots of factors like temperature or the size of the compost bin and what's in it.

But in a few months, you'll have a rich, organic material to add to the soil in your garden.

So, something that was once an unwanted, spoiled orange or watermelon rind, Can now help grow fresh fruits and vegetables for us to eat.

KNAPP: Recycling your organic waste is really just a way that you can in your own life, help to take care of our environment and our planet.

This is really important moving forward as there's more and more people on Earth and we will generate more and more waste.

And we've got to come up with good ways to handle this stuff so that we're not filling up our landfills.

CARTAN-HANSEN: If you want to learn more about garbage, check out the Science Trek website.

You'll find it at Science Trek dot org.

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By the Idaho National Laboratory, mentoring talent and finding solutions for energy and security challenges, by the Friends of Idaho Public Television and the Corporation for Public Broadcasting.