When Vinton L. Pickens and her late husband Robert moved to Loudoun County in 1936, they built a "modernistic house with a Norman influence" and four towering chimneys, that would have been just as appropriate for the French countryside as it is for its 281-acre site along the Potomac River.

But now Janelia Farm, the rolling pastures and manicured formal gardens filled with hundreds of spring flowers in full bloom and the mansion have been caught in the middle of the rush by commercial developers to buy land along Leesburg Pike (Rte. 7), from Sterling Park to Leesburg.

Pickens, 87, has agreed to sell her home and land to two developers, the Mark Vogel Cos. of Washington and the Stuart Bernstein Cos., for an amount that will be made public when the deal is settled in a few weeks.

Janelia Farm, north of Ashburn, is wedged between Xerox Corp.'s proposed 2,300-acre Potomac Park mixed-use development and the 576-acre homesite of the late Marcus Bles, the man who once owned the land where the Tysons Corner Shopping Center is situated.

The Bles property is to include a new engineering campus for George Washington University and a commercial research and development office park to be built by The Charles E. Smith Cos. and New York developer Michael Swerdlow.

Pickens' contract with Vogel and Bernstein is full of stipulations. It grants her life tenancy in the home, and the developers have promised to maintain the 50-year-old mansion and grounds in perpetuity as the centerpiece of the campus-style, low-rise commercial development Vogel says he wants to build on the site.

"To disturb the plantings and grounds would be wrong," Vogel said.

Towering evergreens dominating one side of the house were "family Christmas trees" during the years she and her husband Robert, a newspaper reporter and author, raised their family, Pickens recalled.

In the early 1930s, Pickens and her husband were in Europe. "Everything was bad everywhere," she said. "He said we should go back [to America] and buy some land because it was the only thing 'that is going to be worth anything.'

"We came back and decided to buy in Virginia rather than in Maryland," she said. Construction of the white-painted brick house, which has eight fireplaces, started in 1935. The Pickenses moved in a year later.

Pickens said she plans to monitor Vogel and Bernstein as they start to develop Janelia Farm, which is named for her daughters, Jane and Cornelia.

"We moved here from a beautiful neighborhood in Washington. There was considerable resentment of us because we spoiled the best blackberry patch in the area," the genteel but occasionally feisty Pickens explained.

"I moved from the city to the country, and now the country has deserted me," she said. "But there is no reason why an urban or suburban area cannot be beautiful. Eastern Loudoun can be beautiful if we put our minds to it."

She should know. In the early 1940s she was a major force behind the creation of the Loudoun County Planning Commission, a proposal that many of her fellow residents saw no need for. She became the commission's first chairwoman and has long been active in Loudoun County land-use issues.

"We will not be competing with Xerox" for tenants, Vogel said. "We will be looking for the specialty tenant who will appreciate being near this house, the gardens and having access to the 67 acres along the Potomac River that will be left undisturbed."

The developers' desire to maintain the house and grounds was a major factor in Pickens' decision to sell to the Vogel-Bernstein joint venture. She had been besieged by brokers and developers in the rush to buy the remaining land along the Leesburg Pike corridor.

Leesburg broker Tom Jewell, of the real estate company King and Cornwall, introduced Vogel and Pickens "over a cup of tea" nearly a year ago, Vogel said, as he and Pickens pointed to the views from the house of Sugarloaf Mountain and the spots where the cattle that usually roam the pastures were hiding from visitors.

"They always disappear when it rains or somebody wants to see them," Pickens said.

Vogel said he wants to make sure the property is not adversely affected by any future road interchange or improvements to Leesburg Pike near the farm. He said he is working with another developer, Evans Co. of McLean, which owns vast tracts on the south side of Leesburg Pike, to see if an agreement can be reached to make certain that any road improvements would be built on the Evans' site.