Beginning on Nov. 29, Sixth Engine turns its patio into a Christmas tree lot to raise money for charity. (Fritz Hahn/The Washington Post) Sixth Engine turns its patio into a Christmas tree lot to raise money for charity. (Fritz Hahn/The Washington Post)

Christmas tree lots pop up everywhere this time of year: church parking lots, gas stations and, on Massachusetts Avenue NW, a restaurant's front patio.

From today through Christmas, Sixth Engine's spacious outdoor dining area is filled with rows of Douglas and Fraser firs, measuring anywhere from four to eleven feet tall, as well as wreaths and garlands. Three hundred trees were trucked down from the Crystal Spring Tree Farm in Lehighton, Pa., which also supplied the White House's tree.

The trees are priced from $40 to $140, depending whether you want one sized for a studio apartment or a penthouse with elevated ceilings. But here's the thing that will make your heart grow three sizes: The owners of Sixth Engine run their tree lot as a non-profit, working with the D.C. Firefighters Burn Foundation. Last year, Sixth Engine raised $5,000 for charity, according to co-owner Jeremy Carman, and is hoping to top that in 2013.

Tim Walsh, one of the partners in Sixth Engine, spent his teenage winters working at Christmas tree lots while growing up in Bethesda: "It's in my blood," he says. So when Sixth Engine's team was trying to figure out ways to utilize their patio during the winter, a tree lot seemed like a natural idea.

On Dec. 7, from 11 a.m. to 2 p.m., the lot will welcome Santa Claus (on a Harley) and a vintage fire engine driven by D.C. firefighters for kids to see. On Dec. 11, Carman is organizing a Neighborhood Holiday Party in Sixth Engine's dining room. There's no charge to stop in after 7 p.m. for free hors d'oeuvres and punch (hot toddies and warm drinks will be for sale). Purchase a D.C. Fire Department ornament for your tree and not only do the proceeds go to the Burn Unit at Washington Hospital Center, but you'll be entered into a raffle for dinner at Graffiato, magnums of Champagne and other prizes.

The Mount Vernon Triangle Christmas Tree Lot is located at Sixth Engine, 438 Massachusetts Ave. NW. It's open from 4-10 p.m. on weekdays and 10 a.m.-10 p.m. on Saturday and Sunday. Free hot beverages are included with all purchases, and free same-day delivery is available – just remember to tip your driver.