Dried out Christmas trees have been accumulating on D.C. sidewalks in recent weeks, as city crews have fallen behind collecting them. The District Department of Public Works changed how it collects trees this holiday season, and now says it underestimated the demand for tree pickup.

In past years, DPW told residents to leave trees where trash and recycling are collected—whether in the alley or on the curb. Trees put out in a timely fashion would be taken to be chipped and composted, creating a rich soil amendment residents could pick up in the spring for landscaping use.

But this time around, residents were told that in order to have their trees composted, there was an additional step they had to follow: call 311 to set a date for pickup. Chris Geldart, director of DPW, says the reason for the change was to increase the rate of composting and help route city trucks efficiently.

But for many residents, those tree pickup appointments came and went, while the trees remained. The problem, according to Geldart, was that many more people called 311 than expected.

“We didn’t think it was going to take off as much as it did, so in the first couple of days, we almost tripled the amount of crews that were out there to pick up trees,” says Geldart.

There are now 19 crews collecting 1,600 trees a day, according to Geldart. He says the crews are now “back on track” with collection, missing fewer than 2 percent of tree pickup appointments.

If your tree is still sitting out at the curb after your pickup date, Geldart asks for patience: “Leave the tree there,” he says. “We’re getting out there.”

Trees will be picked up for composting through January 31. After that, trees will be collected with trash and sent to the landfill or incinerator.

This story originally appeared on WAMU.