Recycling bins across the Twin Cities will soon overflow with discarded packaging, wrapping paper and other detritus of the holiday season. But not all of it belongs there, causing extra work this year for the people who sort through our waste.

Batteries and holiday lights wreak havoc at local sorting centers, while some toy packaging and disposable cups must take a long and expensive trip to the landfill or incinerator. Even some gift wrap isn't recyclable. Getting that stuff out of recycling bins is a higher priority this year, local recycling companies say, since China no longer wants much of America's recycling.

That has flooded U.S. markets with extra plastic, paper and other recyclables. That means sorting centers have to do a better job separating recyclable materials from everything else so they can sell a higher-quality product. It's true even in Minnesota, which exported less waste than coastal states.

"Our chant is, 'We need to get back to basics,' " said Julie Ketchum, a local spokeswoman for Houston-based Waste Management. "It is about collecting and processing materials that have end-markets and that have value."

The goal is to reduce "wishcycling," the practice of tossing questionable items in the blue bin in hopes they can be recycled, which has grown more common with the spread of single-sort recycling.

"Industrywide, we're seeing a shift in education from 'recycle more' 'to 'recycle better' — or 'recycle right,' " said Lynn Hoffman, co-president of Eureka Recycling, which now has an app helping customers determine what to put in the bin. Many haulers and counties now post similar information online, since some areas accept items that others do not.

So once the presents are opened and the parties are over, how should we dispose of our holiday waste? What belongs in the trash? And where do all our Christmas trees go? The Star Tribune asked local recycling pros to weigh in.

Holiday lights

Holiday lights cause major headaches at sorting centers. Along with hoses and extension cords, they wrap around cylindrical screens at the start of the sorting process and must be frequently removed.

"We see a lot of Christmas lights being thrown in the recycling and those are bad," said Bill Keegan, president of Dem-Con Companies in Shakopee.

The lights can still be recycled, however. The Recycling Association of Minnesota maintains a list of drop-off locations on its website.

Extracting value from them is more difficult than extension cords, which contain more copper and no bulbs. Typically they have been shipped to China, where some factories use shredders, water and gravity to separate materials for new products. But new Chinese policies have essentially barred the discarded lights from entering the country, said Adam Minter, a Minnesota native who's an authority on global recycling markets.

Gift wrap

Wrapping paper may be recyclable if it is just paper. Generally paper with a foil-like shine or peppered with glitter is destined for the trash. The same goes for any with ribbons and bows.

"Some of it can be recycled, but the stuff that can is still a very low-value product," said Keegan, with Dem-Con. "But a lot of it cannot."

Advice about what to do with basic wrapping paper varies, however. Anoka, Ramsey and Dakota counties say to throw it away. Minneapolis says to recycle it.

"It's very difficult to know 100 percent whether it's all paper or not," said Paul Kroening, Hennepin County's recycling program manager.

Plastic packaging

If you needed a knife or a pair of scissors to break open plastic packaging, chances are it isn't recyclable. The rigid packages are typically called "blister packs."

"To be safe, if an electronic or a toy comes in plastic, that plastic is not recyclable," said Kate Davenport, co-president of Eureka.

Eureka, which processes recycling for Minneapolis and St. Paul, generally wants to see No. 1, No. 2 and No. 5 plastics.

Packing peanuts and Styrofoam are made from polystyrene — No. 6 plastic — which generally is not recyclable in Minnesota. Plastic film, such as bags covering a new computer, is recyclable if taken to retail drop-off locations. A list of plastic bag drop-off locations is available here.

Batteries

A big concern lately for sorting centers is fires caused by lithium batteries improperly tossed in the recycling bin. Keegan said the recycling industry nationally is losing about one facility a month to such fires, including one in Blaine this summer, often from rechargeable batteries inside electronics.

"Those are now in everything from greeting cards that sing to you to tiny little drones … they're ubiquitous," said Hoffman with Eureka. "And they're extremely dangerous."

Batteries should not be recycled in the curbside bin. A full list of drop-off locations is available at call2recycle.org/locator.

Boxes

Boxes are becoming a more common staple of the holidays as people shop more online. The good news is they are very recyclable through curbside bins.

Recyclers advise removing tape and any additional material inside and then flattening them. Otherwise, sorting machines sometimes mistake small cardboard boxes for plastic containers — which must be separated later.

Plates, cups

Most paper cups are not recyclable, since they are typically lined with plastic. Many red plastic Solo cups made from No. 6 plastic are also not recyclable in Minnesota.

Paper plates are also generally not recyclable, but certified compostable plates are accepted by organics collection programs.

Trees

Thousands of trees are disposed of after the holidays, and most of them are either composted or burned to generate heat and power. Some areas pick them up, while others have drop-off locations.

Many trees are ground up and used as fuel for the burner next to the Science Museum in downtown St. Paul, generating power and heating downtown office buildings. Trees collected by Minneapolis are sent to the garbage burner beside Target Field, which also generates energy.

The Shakopee Mdewakanton Sioux Community's organics recycling site in Shakopee grinds and composts the trees it receives from haulers. Specialized Environmental Technologies composts them in Rosemount and sends some to the St. Paul burner.

Correction: This article has been updated to reflect a 2019 change in Ramsey County's guidance for disposing of gift wrap.