NORWALK, Conn. — The Connecticut Tree Festival will return to Norwalk’s Cranbury Park on Saturday, May 21, for its 10th year as a free family event. Attendance is anticipated to be over 2,000 — from an initial turnout of 250 in 2007.

The event is free to the public, including admission, parking, chances on a variety of door prizes, expert advice on tree-planting and a picnic-style lunch. Over 40 exhibitors will form a midway of educational booths. Two bucket rides, a rope-climb carrying youngsters to the park’s treetops, and face-painting are among the most popular activities.

Why trees? They offer both both esoteric and practical benefits. “Trees are a way of showing we believe in tomorrow,” notes a festival news release. They also anchor urban environments, “knit(ting) together the social fabric of neighborhoods, beautifying the landscape with their foliage and stateliness.”

Trees also increase property values and cut costs. They filter impurities from the air, provide shade and improve storm water management, helping to prevent erosion and flooding. Studies show treed lots increase residential property values up to 17 percent, and trees can cut homeowners’ energy costs by $150 and $250 a year.

They can also add to public revenue, attracting businesses and visitors. In addition to being obvious sources of things like building materials and fruit for humans and wildlife, trees can also yield music instruments, or be used as memorials and windbreaks.

The festival will run from 11 a.m. to 3 p.m., rain or shine, thanks to the work of a committee of Norwalk and Wilton volunteers, headed by Paul Sotnik, Norwalk’s senior civil engineer.