A rose by any other name would have at least 652 companions at the New York Botanical Garden’s Peggy Rockefeller Rose Garden, where more than 3,780 plants are in their peak of bloom and sweet-smelling fragrance. Of all NYBG’s horticultural displays planned by important landscape designers, the Rose Garden is perhaps the most fascinating. The garden is calling the celebration of its two decades “Resplendent Roses: Flower, Fragrance, and Form.” But the Rose Garden’s history goes back much further: It was first designed in 1915 by the distinguished New York landscape gardener Beatrix Farrand. She included an elaborate iron trellis enclosure for climbing roses that would “protect the many valuable plants from possible pilfering,” as she wrote in her presentation.

At the time, the NYBG was unable to raise the estimated cost of $10,000. Instead, a scaled-down version without the enclosure was planted in 1918, and then dismantled in 1969 and forgotten. Forgotten, that is, until 1985, when the chairman of the garden’s horticultural committee, Elizabeth A. Straus, happened by chance on two of Farrand’s sketches for the Rose Garden. Realizing the opportunity missed, she went into action. With a gift from David Rockefeller of $1 million, the garden was constructed along Mrs. Farrand’s original plan, and named in honor of Mr. Rockefeller’s wife, Peggy, who had long overseen the Abby Aldrich Rockefeller Garden in Seal Harbor, Maine, designed by Farrand in the 1920s for Mr. Rockefeller’s mother.

In designing the Rockefeller Rose Garden, Farrand, who was also Edith Wharton’s niece, was no doubt influenced by her visit in 1896 to the rose garden in Elizabeth Park in Hartford, Conn., the first municipal rose garden in America, which features a central summer house and radial paths. Try as she might to give her garden a regular design, she adhered to her belief that “the plan must be made to fit the ground rather than an attempt made to ignore the natural conditions.” This led to the truncated triangle with three entrances that lies within the contour of a valley at the southeastern end of the garden along the Bronx River Parkway. Its radial paths of crushed stone dust meet at a seven-sided arbor. This domed lattice structure sits within a circular trellis, now adorned with a white climber rose tinged with pink called ‘Awakening.’

When the city’s Art Commission approved the final design, it insisted on retaining Farrand’s beds perpendicular to the paths that made it a library of roses rather than simply a series of decorative borders. The trellis fence enclosure, designed by the architect Robert E. Meadows and based on Farrand’s sketches, was fashioned in rustproof galvanized steel instead of iron.

Last year, following the arrival of Peter E. Kukielski as NYBG’s curator of the rose collections, the garden was completely restored, with at least 400 underachievers removed, and more than 1,700 plants added. Many of them were imported from England, France, Germany, Italy, and Canada, as well as Texas and Iowa, to bring to the garden the most up-to-date varieties of roses. This month, the new plantings have come into their own, and the 1.04-acre garden flourishes as never before with varieties that will bloom all summer into fall.

A walk in the garden — preferably in the fresh morning hours — is enhanced by realizing the individual history each rose brings to this resplendent and fragrant array across 83 beds. Mr. Kukielski continues Farrand’s tradition of highlighting the shrub-like heritage or antique roses across the back border. From ancient times, in both the East and West, roses have been symbolic to important rituals and daily habits. Simply reading the label for the Rosa gallica officinalis recalls the discovery of its medicinal qualities that gave it the name Apothecary’s Rose when it became established in the little town of Provins in the Champagne region of France.

As Mr. Kukielski said: “In 1867, the first rose was hybridized, a hybrid tea rose called ‘Rose of France’ that introduced the modern era.” Hardier varieties are bred now, he says, to be more fragrant, even thornless and disease-resistant. Beyond emphasizing the garden’s encyclopedic purpose, Mr. Kukielski has mastered the art of planting one family of flower around the perimeter so that they show off tremendous variety of color, form, and foliage as in any other mixed flower border. And in the central beds, great swaths or solid blocks of floribundas in one color, like reds blending into apricots, make for a dramatic palette.

David Rockefeller returned to the garden for a visit last week on this anniversary. Although his wife died in 1996, the deep red Peggy Rockefeller roses are blooming.

Until November (Bronx River Parkway and Fordham Road, the Bronx, 718-817-8700, nybg.org). For more information about rose-related events at the garden, please see the Calendar page.