Varying in height from 3 inches to 3 feet, tulips (Tulipa spp.) raise goblet-shaped blooms to the sun in spring. Native to Turkey and the Himalayas, they thrive in areas with dry summers and cold winters in U.S. Department of Agriculture plant hardiness zones 3 through 8. Tulips generally are propagated by dividing offset bulblets as only species types come true from seed (produce flowers that look identical to those on the parent plant). It may take four to seven years, however, for those seedlings to grow large enough to flower.
Understand Tulip Reproduction
The original tulip bulb you planted will shrivel after it blooms. Before doing so, it should produce a daughter bulb -- sometimes called the primary bud -- and two or three bulblets called offsets or secondary buds. The daughter bulb will flower the following spring. The two or three offsets that appear at the base of each daughter bulb generally take longer to bloom. The largest ones should flower two years after they appear, while the smaller ones may take three years.
Divide Tulip Offsets
To divide tulips, mark their location with stones or stakes while they are blooming in spring so you can find them easily later. In autumn, dig up the bulbs and break the bulblets away from the bases of the daughter bulbs. Replant all of the bulbs and bulblets 6 to 8 inches deep and 4 to 6 inches apart for hybrid tulips, and 3 to 5 inches deep and 3 to 4 inches apart for smaller species types.
Prepare Tulip Seeds
Tulips seeds should ripen by mid-summer, generally in July. After the seed pods turn brittle, gather the flat, brown, teardrop-shaped seeds and spread them on paper towels to dry. Store them in paper envelopes until you are ready to plant them.
A few species types of tulips – such as clusiana v. chrysantha (hardy in USDA zones 3 through 9), kaufmanniana (USDA zones 3 through 8) and turkestanica (USDA zones 4 through 8) -- germinate best if given three months of relatively warm temperatures before three months of cold temperatures. To provide such conditions, sow them in late summer or early autumn. For most other varieties, you can wait until late autumn.
Plant Tulip Seeds
Fill the bottom of a pot that is 6 inches deep with 2 inches of gravel to provide the good drainage that tulips require. Add a sandy type of potting soil, such as cactus mix, to within 1/2 inch of the pot’s rim. Spread the tulip seeds over the surface of that mix, about 1 inch apart, and cover them with 1/3 inch of the mix or fine grit.
Dig a hole as deep as the pot, either inside a cold frame or in another protected outdoor location, and bury the pot up to its rim. A pot outside a cold frame should be covered with hardware cloth to protect seeds from rodents. If the mix is kept damp, the seeds will begin to germinate in early spring, resembling blades of grass.
Grow Tulip Seedlings
You can leave the seedlings in their pot for their first 18 months. They will die back in early summer and remain dormant until the following spring, just as adult tulips do.
Keep their mix barely damp during the summer and bury the pot as before during the seedlings' first winter. Transplant the dormant little bulbs into the ground in early fall of the following year, placing them 2 inches deep and 2 inches apart, keeping in mind you will need to give them twice that depth and distance once they mature.