After months of debating with nearby residents and Montgomery County officials, Alan I. Kay Cos. have agreed to put plants along the terraces of their hotel-office complex atop the Bethesda Metro station.

The Montgomery County Planning Board ordered the firm to place planter boxes on each level of the step-down terraces of the two buildings by April 1. Last August, the board gave Kay until Dec. 31, but the company's lawyers successfully argued that the winter was not a good time to put in the plants. The developer was granted an extension.

The complex at the intersection of Wisconsin Avenue and Old Georgetown Road includes the Bethesda Hyatt Regency and a 15-story office building. Kay executives told the county that the tenants didn't want the planters and that they created a potential liability risk. At the time, Kay said, Hyatt officials couldn't assure him that its guests wouldn't throw the planters over the side of the terraces.

Rob Bushnell, a site plan enforcement coordinator for the county planning board, said the company wanted to put plastic plants in the boxes to save on maintenance costs and to keep from having to replace dead plants. But the board's staff didn't agree.

"People would realize they weren't real and that wouldn't have worked out," Bushnell said.

The National Capital Planning Commission has denied a request by the owners of the Fourways Restaurant near Dupont Circle to rezone their property to build a seven-story condominium and has sent the case back to the D.C. Zoning Commission.

The planning commission, which must approve or deny zoning cases where there are federal interests involved, has asked the D.C. zoning board to reopen the case to further examine the range of uses of the property, which includes the Fraser Mansion, a federally registered historic landmark.

Last month, the D.C. commission voted 3 to 1 to rezone the property owned by Fourways of Washington Ltd., whose general partner is Walter Sommer. Fourways officials have argued that the rezoning is needed to prevent the company from going bankrupt, but nearby residents have been opposed to the rezoning because they fear the project will lead to further commercial development in the area.

Bancroft Homes, an Owings Mills real estate developer, has laid off 100 employees and postponed construction of a 5,000-home project in Baltimore County, company officials said this week. Most of the laid-off workers were architects and engineers.

Terry Rubenstein, coowner of Bancroft, blamed "cash-flow problems" for the delay in work on the massive Lakeside project near Owings Mill. Construction on the first phase of Lakeside, which would be the county's largest residential development, was to begin this spring. But Rubenstein said ground breaking has been pushed back until late summer or early fall. Rubenstein said the problem arose when a Wall Street firm that had expressed interest in becoming a financial partner pulled out of the deal last year.

Here's the latest in the fight over a 1,511-year-old oak tree outside Charleston, S.C.: The state attorney general's office said this week that the city is within its rights to use eminent domain to acquire the tree.

Mayor Joseph P. Riley Jr. has proposed that the city acquire Angel Oak and the land on John's Island around it for a park. The area is outside Charleston's city limits.

But S.E. (Speedy) Felkel, who has owned the tree since 1963 and charges visitors $1 to see it, said the tree is not for sale. He promised to go to court if the city tries to seize it.

After the attorney general's office's nonbinding ruling, State Sen. Sherry Martschink said she has introduced legislation that would ban such out-of-jurisdiction condemnations for recreational purposes.

IN THE BUSINESS ... Shirlington Gateway, a 12-story, 214,408-square-foot building in Shirlington that stood mostly vacant for more than a year, is now 70 percent leased, its developer, the Weissberg Corp., reports ... The General Services Administration has leased 488,300 square feet of space at the Lincoln Place office complex in Pentagon City to serve as headquarters for the Drug Enforcement Administration and the U.S. Marshals Service. The largest single-lease transaction by GSA in nearly 20 years has an aggregate lease value of more than $100 million ... Homeowners are expected to do more remodeling than ever in 1988, according to Cahners Publishing Co., which monitors the remodeling industry. Cahners predicts that total spending for remodeling this year will rise 9.1 percent over last year's levels to a record of $110.3 billion ... The RELO/Inter-City Relocation Service estimates that six out of every 10 individuals transferring from one location to another during 1987 moved to states in the Southeast and Northeast ... The Henry A. Long Co. has bought the Gates Corp.'s Cheyenne Mountain Inn and Country Club in Colorado Springs and has formed International Conference Resorts of America Limited to own and operate the facility as well as other conference centers nationwide ... The Prince George's County Board of Realtors has donated 2,000 smoke detectors to the county fire department for free distribution to county homeowners ... Ken Murphy & Associates, a Vienna real estate sales firm, recorded more than $250 million in sales in 1987 ... Evergreen Development Associates bought 14.34 acres at Loudoun Tech Center on Rte. 28 to be developed as Cornerstone, a 230,000-square-foot office building complex. The first building will be finished in late 1988 ... Shannon & Luchs Realtors residential sales division set a company record for sales in 1987 with a total dollar volume of $2.3 billion and more than 15,000 homes sold.

PERSONNEL FILE ... Washington Homes Inc. has named Ann T. Kalmus as its 1987 salesperson of the year ... CRI Inc. has appointed Jerry H. Herman executive vice president of CRI Institutional Real Estate Inc. ... Lee Kendrick, the mechanical/electrical engineering subsidiary of Dewberry & Davis, has appointed Allen C. Skiles president and chief executive officer ... Fred B. Hetzel, a Loudoun County real estate broker, has been appointed to the executive committee of The National Association of Realtors ... Combined Properties Inc. has named Gene Patton vice president of finance and Joe B. Conn vice president-counsel ... Sigal Construction Corp. has named Benny J. Pasquariello senior vice president for the company's base building division ... Jo Ann Aguilar of Annapolis has been elected president of the Central Maryland Chapter of the Community Associations Institute ... Suzi Slye, broker-owner of Slye Real Estate of Potomac, has merged her company with Mount Vernon Realty, Noah-Cummings Inc. to form Mount Vernon/Slye Realtors.