Hybrid tea roses (Rosa x hybrida) are the product of a cross between hybrid perpetual roses and old-fashioned tea roses. They are set apart by their large, high buds and tall, straight stems. The hybrid tea rose's long, pointed buds open by slowly unfurling. Hybrid tea roses generally produce only one blossom at the end of each stem, rather than clusters of flowers, and they have an open habit. Virtually all hybrid tea roses are repeat bloomers throughout the growing season and offer some degree of fragrance. Hybrid tea roses grow quickly and reach their mature size of 3 to 8 feet tall within only three to four years, depending on the variety and the growing conditions. You can plant them year-round, ideally in fall or in early spring when they are still dormant.