Gardening Articles: Flowers :: Bulbs
by National Gardening Association Editors
All flowers are beautiful in their own way. But no other flowers herald spring like tulips, which captured the imagination of the Dutch some 400 years ago and can still steal the show today.
Tools and Materials
- High-quality tulip bulbs (in mild-winter areas, chill for six to eight weeks)
- Trowel or bulb-planting tool
- Bulb fertilizer
Quality bulbs. Start with quality bulbs, most often from a mail-order supplier but also from a well-stocked garden center. The Netherlands tightly regulates its tulip growers, and as a consequence, all Dutch tulips are of good quality.
If you're shopping at a garden center, shop early in the season and choose only bulbs that are firm and free of defects such as cuts, bruises, or mold. Later in the season, be wary of store-bought bulbs or ones offered at significant discount. We also recommend you buy tulips by variety or species name, not color. "Red tulips" for instance, can mean different kinds of varying performance. Or you may get a mixture of colors.
Mild-winter tulips. If you live where winters rarely or never reach freezing temperatures, tulips likely won't grow all that well. However, you can still grow tulips if you chill them for six to eight weeks before planting (see below). The best choices are Darwin Hybrids or Single Late varieties. The long, strong stems of these tulips are more tolerant of wind and rain, and their midseason blooms appear before hot weather or spring weather.
Species tulips. Or consider some of the species tulips that are better suited to milder climates. These include lady or candy tulip (Tulipa clusiana), with rosy red petals that are white inside; Candia tulip (T. saxatilis), with vivid rose-lilac petals and a yellow base; and yellow Florentine (T. sylvestris). These are smaller and less dramatic than hybrid tulips but are still full of tulip character.
When and where to plant. Plant tulips any time the soil 6 inches deep is 60° F or colder. As a general guide, plant in September or early October in USDA Climate Hardiness Zones 4 and 5; October to early November in zones 6 and 7; November to early December in zones 8 and 9; and late December to early January in zone 10.
Bulbs in warm areas. In zones 8 through 10, refrigerate tulip bulbs for six to eight weeks before planting. Place them in a paper bag away from ripening fruits (the fruits produce ethylene gas, which destroys the flower bud within the bulb).
How to plant. Tulips grow best in full sun in well-prepared soil with fast drainage. Avoid planting where water collects, or in locations that are prone to late frosts.
The rule is to plant tulips pointed end up and 6 inches deep, meaning 4 inches of soil above the top of the bulb. Plant a little deeper, to 8 inches, if soil is light or sandy, or if pests such as voles are a problem. Those 2 extra inches put them just out of reach of voles. Deep planting also keeps the bulbs cooler, an advantage in mild-winter areas.
For an attractive flower display, plant five tulips per square foot, or 250 bulbs per 50 square feet. Space individual bulbs about 5 inches apart. Use a low-nitrogen granular fertilizer specially formulated for bulbs, and follow label directions about the amount to apply
When planting a grouping, take the extra care to plant at exactly the same depth; this ensures that they all will bloom at the same time. With a shovel, excavate soil to create a level planting base. Set bulbs into the bed, fertilize, and then cover with excavated soil.
After planting, firm soil and water thoroughly. Don't water again until leaves appear. In cold-winter areas (zones 3 through 6), apply straw mulch about a month after planting. This gives the bulbs time to begin growth before the soil freezes solidly. The mulch also protects the bulbs if snow cover is light or nonexistent. In mild-winter areas, mulch after planting to help keep soil as cool as possible for as long as possible.