There are over 3,000 registered varieties of tulips. Tulips are classified into groups based generally on flower form and plant size.
The tulip classifications have evolved over the years, but there are 13 official divisions commonly recognized. Some horticultural groups recognize up to 15 or 16 groups. Most gardeners select their bulbs based on familiarity with a particular class or hybrid, and just as often simply by when they bloom. But if you are planning bulb gardens, it is helpful to know the characteristics of the divisions to help you in not only bloom succession planning, but height, flower shape, and the vast varieties of petal shape, texture and color.
- Single early tulips - single flowers are cup shaped and no more than 3” across when fully opened, primarily short stemmed with early to mid season flowering. Plant height can range from 6” to 18” tall.
- Double early tulips - fully double flowers are bowl shaped and up to 3” across when fully opened, primarily short stemmed and early flowering. Plant height is 12-15” tall.
- Triumph tulips - single cup shaped flowers are about 2 1/2” wide, medium length stems and flower mid to late season. Plant height ranges from 12-24” tall. Original hybrid was a cross between cultivars of the Single early tulips and the Single late tulips.
- Single late tulips - single flowered in a cup or goblet shape up to 3” across, primarily long stemmed and late flowering. Plant height ranges from 16-30” tall. Some plants can produce multiple blooms on a single stem. This category includes the original Darwin cultivars, which were used to hybridize the Darwin hybrids.
- Darwin hybrid tulips - single flowers have an ovoid shape and are 3” across, long stemmed and flowers mid to late season. Plant height ranges from 16-30” tall, the tallest tulips available. Originated from the hybridization of Darwin cultivars from the Single late category and Tulipa fosteriana. Darwin hybrids are the longest lived tulip variety. The Darwin hybrids are NOT the same as the original Single late Darwin tulips.
- Lily-flowered tulips - single flowered, varied stem lengths, and flowers mid or late season. Flower petals are pointed and curled back.
- Parrot tulips - single flowered varieties have varied stem lengths, and flowers primarily late. Flower petals are fringed, curled and twisted. A Double late, Peony flowered tulip is double flowered, long stemmed and flowers late season.
- Rembrandt tulips - Rembrandts’ coloring is unusual, being striped or marked usually with deep colors on a red, white or yellow background. The marking is caused by a viral infection. These long stemmed tulips are not available commercially, but you can find them in historical gardens.
- Fringed (Crispa) tulips - single flowered, varied stem lengths, flowers mid or late season, and flower petals are fringed.
- Kaufmanniana (botanical) tulips - very early flowering. The bloom opens completely and has a multicolored base. Overall height up to 8 inches. Foliage is sometimes mottled.
- Fosteriana (botanical or Emporer) tulips - early flowering with medium to long stems. The flower is generally large and elongated. Foliage is sometimes mottled or striped in green or gray-green.
- Greigii (botanical) tulips - early flowering with variable shaped blooms, after the Kaufmannianas. Foliage is generally mottled or striped with leaves that are spread out and bent toward the ground.
Additional groups recognized by many gardeners:
- Double late tulips
- Species (Botanical)
- Multiflowering tulips -