The American Horticultural Society’s River Farm has received a $1 million gift from board member Marcia Zech and her husband as part of a capital campaign to preserve the historic Potomac River property that once belonged to George Washington.

The announcement was made during a news conference Monday at AHS’s River Farm headquarters as a new executive director takes charge following more than a year of internal strife over an ill-fated plan to sell the 27.6-acre property.

Keith Tomlinson, former manager at Meadowlark Botanical Gardens in Vienna, Va., replaced interim executive director J. Robert Brackman, who suddenly resigned last month along with five board members who wanted to sell the property.