Unfortunately, most afflictions that tulips suffer can’t be cured once they happen, so prevention is the key to healthy, abundant blooms. To reduce the likelihood stunted growth or disease in the future, it is necessary to diagnose current problems and take corrective action.
Insufficient Cooling
Insufficient winter cooling, warm spring temperatures, or some combination thereof can cause tulips to develop short stems and small flowers or no flowers at all. In severe cases, even the growth of leaves is inhibited.
Stunted growth and failure to bloom are common problems in places where winters tend to be mild. This problem can be prevented in the future by:
- Planting next season’s bulbs in a location where they will receive direct sunlight in the early morning only
- Choosing Darwin hybrids, Lily Flowered Tulips, and other long-stemmed, single-flowered varieties that are more tolerant of milder climates
- Waiting until mid-December to plant bulbs in warmer Climate Hardiness Zones 9 and 10 (see the Climate Hardiness Zone Maps for North America or Europe to find your zone).
- Purchasing pre-cooled tulip bulbs or storing bulbs in a paper bag in the refrigerator for about 15 weeks before planting
If storing tulips at home, be sure to keep them away from ripening fruits, which produce ethylene gas that can destroy flower buds inside the bulbs.
Removing Foliage Too Early
Tulip foliage should not be removed until it has turned yellow. Early removal can cause stunted growth or failure to bloom in the following season.
Nutrient Deficiency
Nutrient-deficient soil can prevent tulips from blooming or even inhibit their growth altogether. Add a slow-release fertilizer when planting, on appearance of first leaves in spring, and once a month after flowers bloom until foliage dies back to prevent this problem.
Old or Undersized Bulbs
Tulips will usually only flower from the same bulbs for 2-4 years, and fewer in places where winters are mild. Original bulbs tend to disintegrate after one planting season, throwing off smaller daughter bulbs that are often too little to produce many flowers.
Tulips grown year after year from the same bulbs rarely bloom as impressively as they do for their first year. For large, prolific blooms, use large, fresh bulbs each season.
Rodent Damage
Unfortunately, there are many animals that find tulips tasty, ranging from deer to gophers. Animals may eat portions of the bulbs or even entire plants. Evidence of rodent damage includes half-eaten plants or bulbs, tunnels in the ground, small mounds of earth around the tulip bed, or tiny holes in the dirt.
To protect tulips from rodents, line the tulip bed with wire mesh or plant tulips within wire mesh baskets. Adding a bit of sharp gravel to the planting holes with the bulbs can also help to discourage burrowing rodents.
Bulb Rot
Bulb rot, caused by a fungus, results in wilted, sickly foliage. Rotted bulbs, if dug up, will be either firm and chalky with gray, white, or pink mold or soft and mushy in texture.
To prevent bulb rot, buy bulbs only from reputable mail-order companies, or, if purchasing bulbs from a nursery, avoid those that have mold or abrasions. Also, be careful to avoid nicking bulbs when planting as this will leave them vulnerable to infection.
When planting bulbs, ensure that soil is well drained and that water does not collect in the area, as fungi love moisture. Remove and destroy any plants that have become infected and don’t plant bulbs that appear discoloured, spongy, or moldy. Bulbs that are in good condition at the time of purchase may rot later on if stored in damp areas. In addition, don’t replant tulips in soil where there has been a fungal infestation for at least three years.
Botrytis Blight
This fungal disease, also known as Tulip Fire or Tulip Blight, causes discolouration of foliage and bulbs, ranging from light to dark spots (which eventually expand to create large gray blotches), and in some cases, fuzzy brown or gray mold. Leaves may rot right off their bases and infected bulbs can develop circular, dark, sunken lesions. This infection is most likely to occur when weather is cool and moist, and tulip bulbs with damage such as cuts in their skin are more susceptible to infection.
To eliminate Botrytis Blight, destroy all diseased plants and bulbs. Spray a fungicide that contains mancozeb every 5-7 days beginning when plants reach about 4 inches in height and ending when tulips have bloomed. Remove blooms as soon as they begin to fade, and cut foliage down to the ground when it yellows. Locate the tulip bed in a different place each year in case the soil has become infected.
Viruses
Viral infections that afflict tulips can cause flowers to become spotted, streaked, or mottled, and growth to be stunted. Leaves may also develop white or light green streaks. Plants usually don’t die, but they are severely weakened. Aphids may spread viral infections by feeding on diseased plants and carrying viruses to healthy plants.
Parrot tulips can develop streaky patterns that may be mistaken for viral infection. However, these streaks are genetic rather than viral in origin and don’t represent a danger to other plants in the vicinity.
To eliminate viral infections, destroy all infected bulbs and plants, along with those that have been near them. Gardeners who don’t want to apply toxic pesticides can control aphids naturally using ladybugs, which are voracious predators of aphids. Ladybugs can be purchased at many garden stores or ordered online.
Further Reading
For more on gardening, see:
- How to Grow Tulips from Bulbs
- How to Force Tulips to Bloom Indoors During Winter
- Natural Garden Pest Control
Reference:
- Schrock, Denny, Ortho Books (Eds.). (2004). Home Gardener's Problem Solver. Des Moines, IA: Meredith Books.
Jennifer Copley - Jennifer Copley, BFA, BEd, has a diverse base of expertise that includes research, writing, education, pet care, and various other ...
Comments