Bring your family and a picnic dinner to one of the best concerts of the summer. The Northern Virginia Youth Symphony will perform a free evening concert from 7 to 8 p.m. July 29 at the Newton W. Edwards Amphitheatre in Mason District Park.

The Youth Symphony is composed of four ensembles with more than 200 musicians representing 80 schools in Northern Virginia. The Youth Symphony Orchestra is a full orchestra for high school instrumentalists. Its music director and conductor is maestro Luis Haza.

The Newton W. Edwards Amphitheatre is located in Mason District Park at 6621 Columbia Pike, Annandale. To get there, take Beltway Exit 6 (Little River Turnpike, Rte. 236) east two miles to the left at Columbia Pike to the park entrance on the right.

The program will be canceled if it rains. For more information, call Mason District Park at 941-1730.

Learn how to control midsummer plant diseases during a free workshop sponsored by the Fairfax County Park Authority and the County Extension Office from 7 to 8:30 p.m. July 28 at the Green Spring Horticulture Center, 4603 Green Spring Rd., Annandale.

Tina McIntyre, a Fairfax County extension agent, will present a lecture on hampering the growth of midsummer diseases. She also will discuss how to start late-summer crops. A question-and-answer period will follow.

Telephone reservations are required. For reservations and information, call the Horticulture Center at 642-5173.

The American Lung Association of Northern Virginia will conduct a Stop Smoking Clinic from 7 to 9 p.m. on Aug. 11, 13, 17 and 19 at Hammond Junior High School Auditorium, 4646 Seminary Rd., Alexandria.

The clinic will be staffed by a health educator and several ex-smoker volunteers. It uses a positive behavior-change approach which teaches participants how to quit smoking. A $20 fee is required.

To preregister call 591-4131.

Take an early morning stroll to birdwatch on the wetland boardwalk trail of Huntley Meadows Park from 7 to 9 a.m. Aug. 1. Herons, grebes, egrets, ducks and many other water birds can be seen during early mornings in the park.

Huntley Meadows Park, a Fairfax County Park Authority facility, is located at Harrison Lane and Lockheed Boulevard in Hybla Valley. To get there, take Beltway Exit 1 (Richmond Highway, Rte. 1) south for 3.5 miles; after a right turn at Lockheed Boulevard, it's three blocks to the park entrance on the left at Harrison Lane.

For further information, call the park at 768-2525.