The sixth-annual needlework exhibition in Oatlands will open with a 7 a.m. to 9 p.m. champagne reception tomorrow and run until Sept. 15. Antique samplers of heirloom and museum quality will be featured. Admission is $6. For reservations call 777-3174.

The Martha Washington Smocking Guild, which has been commissioned to make decorations for the White House Christmas tree this year, will demonstrate its skills Saturday.

Exhibition hours are 10 a.m. to 5 p.m. Monday through Saturday and 1 to 5 p.m. Sunday. Admission, which includes a house and garden tour, is $4 for adults and $3 for children 7 to 18 years old and senior citizens.

Guided tours of the Oatlands gardens will resume this month, according to horticulturist Alfredo Siani. The first tour is slated for tomorrow at 11 a.m.; additional tours will be Sept. 13, 20 and 27, also at 11 a.m. Garden tour admission is $3.50; $6 will include a tour of the house, a Greek revival mansion.

The garden, designed by owner George Carter in the 1800s, has been restored and was dedicated by Gov. Charles Robb in May as "Virginia's premiere historic garden."

Oatlands executive director Nicole Sours invites artists and crafts people to apply to participate in the Oatlands' Christmas consignment show and sale, running Nov. 9 through Dec. 15. The annual event is a re-creation of a country family's Victorian Christmas celebration. For an application, call 777-3174 or write Oatlands Inc., Rte. 2, Box 352, Leesburg, Va. 22075. There is a $5 application fee.