Roses bloom on and off throughout the season (from midspring to fall), making them among the most desirable garden plants. Most modern hybrid teas, floribundas, grandifloras, miniatures, and modern shrubs are called ever-blooming, repeat blooming, or free-flowering (remontant), while many old garden roses flower either once a year or once in the spring and again in the fall.
You can expect your roses to bloom for the first time about six to eight weeks after growth starts in the spring. The flower needs that long to form and mature. The first bloom in the spring, when all your roses are in full bloom, is always the most spectacular, making that time of year — whenever it may be in your area — a favorite time for everyone who loves roses. Modern roses continue to produce flowers throughout the season, and the process for repeat flower development takes the same six weeks or so. But the plants almost always have flowers at different stages of growth, making for a continuous display.
Roses that bloom once a season are called once-flowering. These are usually old garden roses or antique roses — those discovered or hybridized before 1867. Some antique roses, namely the hybrid musks, hybrid perpetuals, noisettes, Chinas, teas, and about 60 percent of the rugosas, are ever-blooming. But all the others — like albas, centifolias, damasks, and gallicas — bloom only once. However, the display they put on when they do bloom is worth the wait. As if they’re saving up all their energy for a whole year and then throwing it all away in an explosion of bloom, old garden roses that bloom only once can produce as many as 50 times more total flowers than ever-blooming roses.
These great roses bloom only once a year in spring:
‘Empress Josephine’: This old garden rose has rich pink, semi-double flowers, loosely shaped with large, wavy petals and well-branched growth.
‘Harison’s Yellow’, Rosa harisonii: This flower has cupped, soft yellow blooms with golden stamens.
‘Ispahan’: This damask rose has bright pink flowers, which are loosely double and very fragrant. Though it blooms only once, its bloom season is long.
‘Kšnigin von DŠnemark’: This alba rose grows vigorously and produces very full, medium-sized, fragrant blooms of pale pink flowers with a darker center.
‘Mme. Hardy’: A damask rose whose flowers are pure white, occasionally tinged pale pink, with a green center. The plant grows vigorously, producing very fragrant, cupped, large blooms.
‘Mme. Plantier’: The flowers of this hybrid alba rose are creamy white changing to pure white, with very fully double, flat blooms in clusters. The plant is fragrant, vigorous, and bushy.