Gwinnett County has more Tree City USA towns than any county in Georgia, said Dale Higdon, senior forester with the Georgia Forestry Commission.

That's a national designation that indicates a city is working with national and state foresters on protecting and enhancing the health and number of its trees. (See www.arborday.org for more information.)

Lilburn, the latest to receive the National Arbor Day Foundation's designation brings Gwinnett's number up to 6, Higdon said. It joins Berkeley Lake, Duluth, Norcross, Suwanee and Snellville.

Nationally, Arbor Day is celebrated on the last Friday in April, but many Southern states mark the day earlier, to catch the best tree-planting weather.

Gwinnett's first Arbor Day events are on Friday; the last are in April:

DULUTH: The city's Arbor Day Planting and Celebration is 9 a.m. Friday, at Bunten Road Park. This year's honoree is Jeff Wooten, the city's "champion" mechanic who passed away suddenly last year. After a short memorial service, the tree will be planted, and a short reception will follow. Information: 770-814-6981.

NORCROSS: The city's Arbor Day Celebration is at 10 a.m. on Friday at the Cultural Arts and Community Center. Tree planting followed by refreshments.

Information: Jennifer Peterson at 678-421-2027.

SUWANEE: The city's Arbor Day events center on the planting of up to a dozen trees at 3 p.m. Friday near the new pedestrian bridge that links Town Center and the Suwanee Creek Greenway. Seedlings will be given to each volunteer. Contact Wes Rogers, the city's senior environmental planner, at wrogers@suwanee.com or 770-945-8996 to volunteer.

LILBURN: The city will bestow the Lilburn Historical Society's Arbor Day 2008 award on an individual who has contributed to the community, and plant a tree in his or her honor. This year's Arbor Day celebration will be at Lilburn City Park on March 1. Information: 770-921-2210.

SNELLVILLE: The city hosts a combination Beautification Day and Arbor Day celebration on Saturday, April 19, at T. W. Briscoe Park. Breakfast starts at 8:30 a.m., projects stretch from 9 a.m. to 3 p.m., and the Arbor Day Event will be held at noon.

Attendees are welcome to bring their own rakes, shovels, gloves, planting tools and other items. Children 12 and younger must be supervised by an adult. Bring a sack lunch or enjoy refreshments from the concession stand.

BERKELEY LAKE: The city will plant trees on April 19, but has not yet planned an official celebration, other than its citywide tree assessment on April 22-23.