Tulips belong to a general group of plants that grow bulbs, corms and tubers beneath the soil. These structures are food storage containers and allow the plant to grow quickly, producing flowers and seeds in a very short period of time. Some bulb plants, like tulips, add food stores to the bulb before flowering, others add energy reserves after the flower has produced seed. Both strategies replace the food stores to use during the next season.
Seeds produced from tulips are planted or fall to the ground. Eventually, if conditions are right, the seeds will germinate and new tulip plants begin to grow. Tulips and other bulb plants grow slowly at first. Underground, between the rootlets and the stem, a bulb is forming.
The plant takes in water and minerals through the rootlets and transfers them to the leaves. Photosynthesis converts carbon dioxide, water and minerals into food, which is transferred back underground to the newly forming bulb.
Small bulb plants like muscari can grow large enough to produce more flowers in a single year from seed. Other, larger bulb plants like tulips and daffodils might take up to 3 years before they bloom. In either case, the plant won't make flowers until the bulb is mature.
Tulip bulbs produce offsets from mature bulbs. Offsets are small, young bulbs that are essentially clones of the mother plant. This is another way the plant insures survival. By producing offsets, future generations of plants are ensured, even if conditions are never right for germinating seeds. In this way, the plant can produce offspring in years unsuitable for seed germination.
Tiny bulbs form around the rootlets at the base of the bulb. These grow larger for a year or two until they break off or are taken off. Planted separately from the mother bulb, the offsets grow into mature bulbs and produce flowers in one to two years.
Some tulips belonging to the species variety produce bulblets at the ends of long stolons. These bulblets will eventually grow into mature bulbs. Bulblets may be separated from the stolons and planted out to grow into mature bulbs which flower in two years.
Whether from seed, offsets or bulblets, the formation of the bulb beneath the surface of the soil is how the plant ensures survival for future generations. By storing food and going dormant over the hot summer and cold winter months, tulips make sure they flower at the optimal time for their seeds to form, ripen and possible germinate into new plants that grow bulbs.