Herb gardening has become increasingly popular recently.Freshly prepared herbs from the garden offer more natural flavor than those from the store. And as grocery prices continue to go up, increased interest in growing herbs can be expected.

Soon there will be a new herb garden at the National Arboretum, "a teaching garden, an historic garden, a garden of the finest in design and planting," a gift to the nation by the Herb Society of America. The total cost is estimated at $250,000.

It had been hoped the garden would be partially installed this year, but it did not work out. The money was not forthcoming as quickly as anticipated.

It will contain a formal "knot" garden with plants arranged in intricate patterns resembling various knots. Also planned are specialty herb gardens, for medicinals, flavorings, essential oils, dyes and teas, as well as herbs used by Indians and early settlers. A historic rose and fragrance garden, bounded by evergreen hedges for background, will be featured.

The Herb Society of America includes about 1,200 members organized into 15 units, and including about 500 members-at-large. All the units and the members-at-large, as a group, have contributed to the garden, raising money with benefits and other enterprises. Individual members have also contributed, and about $60,000 has been raised to date.

A National Herb Garden has been a continuing project of the Herb Society since 1965. A Bicentennial dedication ceremony was held in June 1976, and $17,760 was given for the garden.

"The new garden will serve the public well, in educating and helping people understand the long history of herbs in the United States," says Arboretum Director Dr. John Creech.