COLUMBIA, Mo. — Now is the time to prepare for some of the earliest arrivals of spring: flowers borne by Dutch bulbs.
These flowers include the likes of narcissus (daffodil), tulip, hyacinth and crocus.
“We usually plant them in October or early November because the bulbs need about 12 weeks of soil temperatures below 38 degrees to bloom,” said David Trinklein, MU Extension state horticulturist.
These flowers thrive in cool weather, and many Dutch bulbs begin blooming in March. Crocuses can bloom as early as February.
“We appreciate them because they do give us a sense that spring isn’t too far behind,” Trinklein said.
The bulbs need to be planted in the fall to produce a root system and develop the immature flower bud in the bulb.
“These plants need to go through a chilling period in order to elongate what we call the flower primordium, a flower bud in very rudimentary form,” he said. “A bulb plant will draw on its reserves for the flower the following spring. Unless the weather is conducive for the plant to put a lot of energy reserves back into the bulb after it flowers, flowering will decrease each and every year.”
When the soil begins to warm, the bulb will send up foliage, followed by the mature flower bud.
Despite their name, Dutch bulbs are not native to the Netherlands. They were introduced to western Europe from the Ottoman Empire in the 1500s, possibly a Flemish diplomat. Tulips were especially prized in the Netherlands, leading to a market bubble known as “Tulip Mania” in the 1630s, when speculators drove the price of tulips bulbs to astronomical levels before prices crashed.
About 93 percent of all bulbs in the world come from the Netherlands, which produces more than nine billion bulbs annually, according to the University of Vermont.
New plants don’t come from seed, but rather from the propagation of bulblets.
“Bulblets – which form at the base of the bulb on what is called the bulb plate – are harvested. However, bulblets are a mere fraction of the size of the mother bulb that gave rise to them,” Trinklein said. “Therefore, it takes several years of growth even under ideal conditions to grow a mature bulb.”
Dutch bulb success in Missouri depends on correct fall planting.
Generally, bulbs should be planted at a depth of about 2-3 times their height, with the pointy end facing skyward. For new bulbs, Trinklein recommends a slow-release organic fertilizer like bone meal, which contains phosphorous needed to establish roots. It is relatively inexpensive and available at most lawn and garden stores. If you use a bulb planter that bores out a core of soil, simply put in a tablespoon of bone meal and some soil before you drop in the bulb.
“The larger the bulb initially, the more expensive it will be in stores, but the better will be the size and vigor of the flower the following spring,” he said.
Of the major Dutch bulbs, daffodils naturalize most easily in Missouri, while others sometimes have difficulty with the hot weather.
For those who don’t want wait until March for tulips or daffodils, bulbs can be potted in a soilless potting mix, Trinklein said. Pots then can be sunk into the ground for the 12 weeks of required chilling. After that they can be brought inside the house.
“After bringing a properly chilled pot indoors, blooming will happen in quick order. It isn’t unusual to get a tulip to bloom within 10 days of bringing it inside.”
But whatever you do, don’t forget to plant bulbs soon.
“I often get questions from people asking if they can still plant narcissus bulbs in the spring that didn’t get planted last fall,” Trinklein said. “My answer is yes, but they won’t flower until the following year.”
Find more information about Dutch bulbs:
-“Spring Flowering Bulbs: Daffodils” (MU Extension Guide G6610), http://extension.missouri.edu/p/G6610.
-“Minor Bulbs for Early Spring Color” (Missouri Environment & Garden, Vol. 16, No. 10), http://ppp.missouri.edu/newsletters/meg/archives/v16n10/a2.pdf.