Tulips are a refreshing reminder to customers that winter is almost over. Customers’ desire for color at the end of winter creates a profitable crop for cut flower growers using minimally heated greenhouses and high tunnels. Tulip bulbs can be forced to bloom out of season (from December through May) for early spring sales at Valentine’s Day, Easter, and Mother’s Day. Tulip bulbs can also be grown outdoors in raised beds, allowing them to flower naturally for spring sales.
The major groups of tulip flower types are simple petal, parrot, fringed, double flowering, multi-flowering, and lily flowering. Fringed and parrot tulips are considered distinct flower types. The fringed types have a regular tulip bloom with a fringed edge. Parrot tulips, however, have a deeper cut in the bloom edge and are more ruffled overall. Double flowering tulips have a cluster of multiple petals forming the flower head. Multi-flowering tulips have more than one flower per stem. Lily flowering tulips have more pointed petals and usually bloom later than any other type of tulip.
Bulbs are measured by circumference (cm) in a horizontal plane at the middle height of the bulb. The ideal bulb size for tulips is top size 12/+ cm, although some growers use a smaller 11/12 cm size. However, for optimum flower production the 12/+ cm top size is highly recommended because smaller bulbs result in a poorer quality crop with smaller flowers and shorter stems. Bulb orders should be placed with suppliers after Mother’s Day and preferably no later than the Fourth of July weekend. Most suppliers provide the tulips in trays of 500 per variety for a 12/+ size and 750 per variety on the 11/12 size bulbs.
Tulips are one of the most iconic flowers, synonymous with the arrival of spring. Their brightly colored blooms seem to appear overnight, coating fields and gardens in vivid hues. But the process that produces these bulbs and transforms them into flowers is complex, taking over a year from initial planting to harvest.
The Tulip Bulb Lifecycle
Tulip bulbs go through distinct phases during their production cycle
Planting
- Tulip bulbs are planted in fall, usually late September through October. The Netherlands is the major producer of tulip bulbs.
- Bulbs are planted 4-6 inches deep in fields using specialized agricultural equipment. This protects them from winter frost.
- Fields are fertilized and nutrient-rich compost is worked into the soil. This provides food for bulbs to grow.
- After planting, fields are covered with straw or mulch to further insulate bulbs from cold weather.
Chilling Period
- Bulbs require a chill period of cool temperatures around 40°F for 12-14 weeks. This chill period initiates root and shoot growth.
- During this dormancy period, the underground bulb develops its flower parts in preparation for the rapid above-ground growth to come.
Growth Phase
- As soil temperatures increase in early spring, dramatic growth begins above ground.
- Shoots emerge from bulbs as early as March. They appear as curled reddish-green sprouts poking up through soil.
- Foliage elongates rapidly, growing several inches per day. Tall varieties may require staking.
- Flower buds form on stems and elongate into the familiar colorful tulip blooms in April and May.
Bulb Development
- While foliage is growing above ground, bulbs are developing underground. They pull nutrients from the soil, fertilizer, and leaves to nourish the daughter bulbs.
- Tulip flowers are often removed just as they reach peak bloom. This prevents the plant from forming seeds and signals the plant to focus energy on bulb growth instead.
- Removing flowers causes the mother bulb to split into 2-5 new daughter bulbs, multiplying the crop for the next season.
Harvest
- Mature bulbs are harvested in summer once foliage completely dies back, typically 6-8 weeks after flowering finishes.
- Bulbs are lifted from soil and cleaned. They are sorted by size, with largest re-planted and smaller bulbs sold.
- Harvested bulbs are cured for 4-6 weeks in a dry, airy space then stored in a cool spot around 50°F until the fall planting cycle resumes.
Critical Steps for Quality Tulip Bulb Production
Producing robust, high-quality tulip bulbs suitable for transplanting and flowering requires careful attention throughout the process.
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Soil preparation – Fields must be enriched with nutrient-rich compost and fertilizers to feed bulbs. Soil pH is also optimized.
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Pest/disease control – During storage, bulbs are monitored for any disease or damage. Diseased bulbs are discarded to prevent spread.
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Field rotation – Bulb fields are rotated yearly and soil is tested to prevent nutrient depletion and disease buildup.
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Harvesting -Specialized equipment cleanly lifts bulbs from soil without damage. Strict protocols grade and sort bulbs.
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Storage – After curing and before replanting, bulbs are kept dormant in a cool, dry environment to prevent premature sprouting.
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Flower removal – Cutting flowers at their peak signals the bulb to focus energy on multiplying, increasing future yield.
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Chilling period – Bulbs require sufficient cool dormancy to initiate the hormones, cell growth, and energy stores needed for abundant flowering.
Through centuries of honing cultivation techniques, Dutch experts have mastered the art and science of producing vibrant, viable tulip bulbs. While tulip flowers provide a brief but spectacular spring display, what goes on underground to generate those vivid blooms is a complex year-round process.
Table Tulips for Field Production – Grouped by Flower Period
| VARIETY | COLOR | NATURAL FLOWERING SEASON |
|---|---|---|
| Pink Impression | Pink | early |
| Red Impression | Red | early |
| Van Eijk | Pink | early |
| Othello | Purple |
early |
| Bastogne | Red | early/mid |
| Bastogne parrot | Red parrot | early/mid |
| Oxford | Red | early/mid |
| Oxford Elite | Orange/yellow | early/mid |
| Apricot Parrot | Apricot parrot | mid |
| Ben van Zanten | Red | mid |
| Blushing Beauty | Yellow, red blush | mid |
| Don Quichotte | Pink | mid |
| Golden Oxford | Yellow | mid |
| Gwen | White | mid |
| Jan van Nes | Yellow | mid |
| Laura Fyii | Red/yellow | mid |
| Leen van der Mark | Red/white | mid |
| Lucky Parrot | Red/white parrot | mid |
| Negrita Favourite | Purple | mid |
| Barcelona | Pink | mid/late |
| Strong Gold | Yellow | mid/late |
| Synaeda Blue | Lavender/white | mid/late |
| Avignon | Orange | late |
| Big Smile | Yellow | late |
| Flaming Parrot | Yellow/red | late |
| Grand Style | Red | late |
| Ile de France | Red | late |
| Lady Margot | Yellow | late |
| Maureen | White | late |
| Menton | Salmon/pink | late |
| Mrs. JT Scheepers | Yellow | late |
| Purple Lady | Purple | mid |
| Renown | Pink | late |
| Texas Flame | Yellow/red | late |
| Texas Gold | Yelloq | late |
| Queen of Night | Black | late |
| Clearwater | Pure white | very late |
Table Tulips for Greenhouse Production – Grouped by Flower Type
| COLOR | JANUARY | FEBRUARY | MARCH | APRIL | |
|---|---|---|---|---|---|
| Double Early Tulips | |||||
| Abba | red | x | x | x | x |
| Holland Ballet | white | x | x | x | x |
| Largo | red | x | x | x | x |
| Margarita | lavender | x | x | x | x |
| Monte Carlo | yellow | x | x | x | x |
| Mondial | white | x | x | x | x |
| Double late tulips | |||||
| Abigail | dbl Attila | x | x | x | |
| Angelique | soft pink | x | x | x | |
| Don Camillo | dble Don Quichotte | x | x | ||
| Mount tacoma | white | x | x | x | |
| Upstar | pink | x | x | x | |
| Fringed tulips | |||||
| Arma | red | x | x | ||
| Curly Sue | purple | x | x | x | |
| Louvre | pink | x | x | x | x |
| Madison Garden | deep pink | x | x | x | |
| Parrot tulips | |||||
| Apricot Parrot | apricot | x | x | x | |
| Erna Lindgreen | red | x | x | ||
| Flaming Parrot | red/yellow | x | x | ||
| Prof. Rontgen | orange | x | x | x | |
| Rococo | red | x | x | ||
| Salmon Parrot | salmon | x | x | x | |
| Texas Flame | yellow/ red flame | x | x | ||
| Texas Gold | yellow | x | x | ||
| Webers Parrot | pink/white base | x | x | x | |
| Multi-flowering | |||||
| Cloud Nine | pink | x | x | x | |
| H.D. Genscher | creme | x | x | ||
| Silhouette Bouquet | red | x | x | x | |
| Regular cut tulips | |||||
| Ad Rem | orange/yellow edge | x | x | x | |
| Attilas Record | lavender | x | x | x | |
| Barcelona | pink | x | x | x | |
| Baronesse | pink | x | x | ||
| Bastogne | red | x | x | x | |
| Ben van Zanten | red | x | x | x | |
| Bright Pink Lady | soft pink | x | x | ||
| Cafe Noir | dark purple | x | x | ||
| Suitable Forcing Periods | |||||
| Carola | pink | x | x | x | |
| Cassini | red | x | x | ||
| Charmeur | red/white | x | x | ||
| Cheers | creme | x | x | x | x |
| Cherida | creme yellow | x | x | x | x |
| Clearwater | white | x | x | x | |
| Deshima | red | x | x | x | |
| Don Quichotte | pink | x | x | x | |
| Dynasty | pink/white base | x | x | x | x |
| Dreaming Maid | lavender/white | x | x | ||
| Early Glory | pink | x | x | x | |
| Friso | red | x | x | x | x |
| Gabriella | soft pink | x | x | x | x |
| Gander | pink | x | x | ||
| Ganders Overture | creme/pink flame | x | x | ||
| Ganders Rhapsody | pink/white base | x | x | ||
| Golden Brigitta | yellow | x | x | ||
| Happy Generation | white/red flame | x | x | ||
| Holland Beauty | pink | x | x | x | |
| Ile de France | red | x | x | x | x |
| Jack Pot | dark purple/white | x | x | x | |
| Jan Reus | burgundy red | x | x | ||
| Jan van Nes | yellow | x | x | x | x |
| Kais. maria Theresia | soft pink | x | x | ||
| Kees Nelis | red/yellow | x | x | x | |
| La Nouba | white | x | x | x | x |
| Leen vd Mark | red/white | x | x | x | |
| Leo Visser | red/white | x | x | x | |
| Lucky Strike | red/white | x | x | x | x |
| Negrita | purple | x | x | x | |
| Negritas Favourite | purple | x | x | x | |
| Niigata | pink | x | x | x | |
| Orange Cassini | orange | x | x | ||
| Othello | purple | x | x | ||
| Peerless Pink | pink | x | x | x | |
| Pink Impression | pink | x | x | ||
| Prima Vista | red | x | x | ||
| Primavera | pinkish-red | x | x | ||
| Purple Flag | purple | x | x | x | |
| Purple Prince | purple | x | x | x | |
| Red Gander | red | x | x | ||
| Red Impression | red | x | x | ||
| Rosalie | pink | x | x | x | |
| Royal Virgin | white | x | x | x | |
| Sevilla | red | x | x | x | |
| Shirley | white/purple edge | x | x | ||
| Silver Dollar | white | x | x | x | |
| Stargazer | red/white | x | x | ||
| Strong Gold | yellow | x | x | x | |
| Swinging World | pink | x | x | x | |
| Synaeda Blue | lavender/white | x | x | x | |
| Synaeda Show | white | x | x | x | |
| The Mounties | watermelon red | x | x | x | |
| Washington | yellow/red flame | x | x | x | x |
| White Dream | white | x | x | x | |
| White Flight | white | x | x | ||
| Worlds Favourite | orane | x | x | x | |
| Yokohama | yellow | x | x | x | x |
Precooling Requirements
It is highly recommended that you follow the information provided in the Holland Bulb Forcer’s Guide–5th Edition (see References section for more information). There are two main types of bulbs, precooled and non-precooled.
The Holland Bulb Forcer’s Guide defines precooling as “the dry storage of spring flowering bulbs at temperatures between 35-48 °F after floral initiation and development is completed, but prior to planting.” Precooled bulbs need to be planted fairly quickly upon receipt. If precooled tulip bulbs must be stored for a short period, keep them at the temperature specified by the supplier (usually 40-45 °F). The second type, non-precooled bulbs, are stored at non-chilling temperatures (typically 63 °F) until cooling begins by the final forcer. Non-precooled tulip bulbs can be potted and stored in a dark, cool (33-40 °F) barn or shed for 12-14 weeks. Monitor the stacked crates often to prevent the shoots from growing into the crate above.
Greenhouse—Hydroponic in Crates
Reusable water trays are placed in tulip bulb shipping crates. The trays float in a liner that is inserted in the bulb crates. Two kinds of water trays are commonly used—the egg crate type and the prong type. The prong-type water trays are able to accommodate bulbs of various sizes, whereas the egg crate type comes in two different sizes to hold a particular size bulb.
Precooled bulbs are required for greenhouse forcing. Precooled bulbs are planted into the hydroponic trays and typically placed back into a cooler at about 40 °F for 1-3 weeks depending on cultivar and time of year. This temperature allows for some rooting to take place before the bulbs are placed in the greenhouse for forcing. The tulips can then be grown in a cool (40 °F night) or warm (55 °F night) greenhouse. The warmer the greenhouse, the faster the bulbs will bloom.
Level benches are needed so that the water level is the same for the entire crop. Water is added to the trays so that the level of the water just touches the bottom of the bulbs to initiate root growth. Some bulb suppliers recommend removing the paper skin from the base of the bulb to allow faster root growth, being careful not to damage the root area.
The water in the trays should be changed several times during the growing cycle, either by overflowing the crates when watering or completely changing the water. Be aware that dumping excess water on the greenhouse floor increases the humidity in the greenhouse, thereby increasing the chance of Botrytis problems.
Plastic tray and insert for tulip production
Early growth of tulips in crates
Tulips in bud stage
Greenhouse—Soilless Substrate in Crates
The shorter tulip bulb crates are more suitable for growing tulips than the taller lily bulb crates. Place a sheet of newspaper in the bottom of the crate to prevent the substrate from falling out the bottom. Fill the crate with about three inches of moistened substrate. Tulips produce roots at the base of the bulb, so the amount of substrate under the bulb is more important than the depth the bulb is planted. Arrange the bulbs on the substrate in ten rows of six bulbs, or sixty bulbs per crate. The number per crate can vary by bulb size, with as many as 100-105 11/12 cm bulbs being used in some cases. Cover the bulbs with 2 – 3 inches of substrate and then water well. Tips of the bulbs should still be visible after watering the substrate.
If the bulbs previously received their entire precooling period, then forcing may begin by moving the crates into a cool (40 °F night) or warm (55 °F night) greenhouse, or holding in a cool area several weeks to grow roots. If coolers are available, bulbs are planted then cooled at 40 °F (or below to reduce shoot growth) for a total duration of 12-16+ weeks depending on the cultivar and time of year. After cooling, forcing may begin. Protect the bulbs from freezing. Keep the substrate moist at all times, while being careful to keep the foliage as dry as possible when watering.
Greenhouse—Raised Beds
An indoor, raised bed can be constructed using pressure treated wood to create six-inch high sides. When constructing raised beds in a high tunnel or greenhouse, consider the space between the beds for maneuvering equipment.
Raised beds are useful for tulip production because they help to improve drainage and prevent disease problems caused by root rots. Do not replant in beds that have had tulips in the past unless you are able to steam sterilize the substrate at 160–180 °F for 30 minutes. During the heat of the summer when a greenhouse is not in use, plastic covers can be used to solarize (using the sun to heat the soil) the beds for 4-6 weeks.
Growing tulips in raised beds is very similar to greenhouse production of tulips in crates of soilless substrate. Programmed bulbs are used and planted in steam-sterilized soil. Keep the beds well watered and the greenhouse nighttime temperatures between 40 and 55 °F. The warmer the house is kept, the shorter the crop time, but the higher the heating cost.
Field Production
It is easier to plant tulips by digging a trench than it is to plant the individual bulbs. To form a trench, cultivate the planting area 12 inches deep and then shovel the soil to one side of the bed. In field production, tulip bulbs can be planted up to eight inches deep. The deeper the bulb is, the longer the stem will be when pulled at harvesting. If a deeper trench is needed, cultivate the area again and remove more soil. Place the bulbs in the bottom of the trench 6-8 inches deep, leaving about as much space between each bulb as the size of the bulb itself. Cover with soil, being careful not to overturn the bulbs in the process. The loosened soil can be used to create a raised bed over the tulip bulbs. Water the bed well. A preemergent herbicide can also be applied at this time to prevent winter and early spring weed germination.
Low tunnels can be constructed over field grown tulips in early February to force the bulbs into flower in late March, three to four weeks before other field tulips. Low tunnels will also help to protect early crops from deer. Later crops can be protected by placing posts along the sides of the bed and using row cover vertically along each side of the row. Rope zigzagged down the row will support the row cover above the tulips. If the row cover rubs the flowers, the buds will be damaged. For information on how to construct a low tunnel, contact the University of Maryland Extension.
Fertilization
Proper fertilization for tulips used as cut flowers is important. Tulips are not considered high feeders, and the bulbs themselves store many nutrients for the plants’ initial growth. Excessive fertilization can lead to reduced plant height, which may affect marketability. The use of slow or controlled release fertilizers is not recommended as the plant will be harvested before most of the nutrients are released. For field production, use 1.5 pounds of nitrogen per 1,000 square feet at planting, making sure not to allow the fertilizer to come in contact with the bulbs. After bulb emergence in the spring, the application of one pound of actual nitrogen per 1,000 square feet (1.6 oz per 100 sq ft) of row is recommended. The substrate should have a pH of 6.2 to 6.8 for the greatest nutrient avail- ability and plant growth. Adjust phosphorus and potassium to the optimum range based on results from soil tests.
In greenhouse and high tunnel production fertilization should begin after shoot emergence. When the shoots are 2 to 2.5 inches tall use a fertilizer with a 2:1 ratio of calcium nitrate to potassium nitrate after amending the substrate for phosphorus and potassium. Weekly application of this ratio can be used, or a fertilizer injector can be utilized to sup- ply 200 to 250 ppm of N on a constant basis using a well-balanced fertilizer (either 2:1:1 or 3:1:1 nitrogen to phosphorus to potassium ratio) that includes a small amount of phosphorus and potassium. With a soluble salt meter, use the 1:2 dilution method to monitor the electrical conductivity. Acceptable readings should be between 1 and 1.5 mS/cm (mmhos/cm).
Harvesting and Postharvest Handling
Tulips are harvested when petals show color, but are not completely colored or open. When harvesting, tulips can be cut or pulled. Crate-grown tulip stems are cut at harvest time. Tulips grown in the field are pulled at harvesting to increase the stem length. If the soil is soft, the bulb usually comes up when the stem is pulled. When pulling tulips, grasp the stem at the soil line and pull straight up. The stem should snap off at the bulb, producing a longer stem. The used tulip bulbs should be discarded after harvest. This pulling method removes the used bulbs from the bed, making bed preparation for the next cut flower species easier. Rotating tulips to another field the following year will help to reduce disease occurrence.
The stems of pulled tulips should be cleaned after picking. Simply swish a handful of stems in a large bucket of water to clean the soil off the stems before placing them in a bucket of water with preservative. If the tulips experience wilting after harvest, any bent stems must be wrapped or somehow supported in the bucket while rehydrating. Otherwise, they will remain bent even after being properly hydrated. Tulips can be stored in a cooler in water or dry at 35 °F for up to one week. If stored dry, they must be supported when rehydrating. Tulips continue to grow after cutting, up to six inches after placing them in a vase.
How 2 Billion Tulip Bulbs Are Produced and Harvested – Tulips Cultivation Technique in Green House
FAQ
How do tulips reproduce bulbs?
Tulips will need a full year’s growth in order to start multiplying and spreading. This means that the initial process will begin after their first bloom in spring. When this process begins baby bulbs will sprout from the main tulip root. This usually creates 2 to 5 more bulbs each cycle.
Do tulip bulbs multiply on their own?
Tulip bulbs multiply slowly by producing small offshoots that take up to three years to bloom.
Do tulip seeds turn into bulbs?
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1. Seed Germination:Tulips can reproduce from seed. Once scattered, the seeds germinate and sprout into small plants.
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2. Bulb Development:The seedlings then begin to form bulbs, which are underground storage organs that contain the plant’s reserves of nutrients.
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3. Growth and Flowering:The bulb gradually grows larger over the next few years. Eventually, it will be large enough to produce a flower, which can take several years from when the seed was sown.
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4. Bulb Propagation:Once a tulip plant is established, it can also produce new bulbs, called offsets, at the base of the main bulb. These offsets can be separated and grown to produce more tulips.
Is it okay to leave tulip bulbs in the ground all year?
While you do not need to dig and divide your tulips every year, they should be dug up at least every 3-4 years if planted in the ground. If you are not digging them up yearly, make sure they are not in an area of the yard where they will be watered all summer. Too much water over the summer will rot/kill your bulbs.
Where do tulip bulbs come from?
The Netherlands is the world’s main producer of commercial tulip plants, producing as many as 3 billion bulbs annually, the majority for export. “Unlike many flower species, tulips do not produce nectar to entice insect pollination. Instead, tulips rely on wind and land animals to move their pollen between reproductive organs.
When do tulip bulbs grow?
July – Sept. Multiplying Up to five small bulbs can be expected to grow out of the mother bulb. They form their roots slowly, and develop their blooms and leaves within the bulb, for next year’s plant. Tulips.com is your source for the biggest and best flower bulbs for fall planting. And fresh cut flowers for any occasion.
How are tulips propagated?
Tulips can be propagated through bulb offsets, seeds or micropropagation. Offsets and tissue culture methods are means of asexual propagation for producing genetic clones of the parent plant, which maintains cultivar genetic integrity. Seeds are most often used to propagate species and subspecies or to create new hybrids.
How long does it take tulips to flower?
Tulips grown from seeds often need five to eight years before plants are of flowering size. To prevent cross-pollination, increase the growth rate of bulbs and increase the vigour and size of offsets, the flower and stems of a field of commercial tulips are usually topped using large tractor-mounted mowing heads.
Do tulips have leaves?
Tulips are perennial herbaceous bulbiferous geophytes that bloom in spring and die back after flowering to an underground storage bulb. A bulb can be as much as 5 cm (2 inches) in diameter or as small as 1 cm (0.4 in). Tulip stems have few leaves. Larger species tend to have multiple leaves.
Where can I buy tulips?
Tulips.com is your source for the biggest and best flower bulbs for fall planting. And fresh cut flowers for any occasion. Always overnight delivery. Direct from our family farm.