The tulip is a valuable addition to every garden landscape. Its bright splash of color can begin in early spring and continue into June depending on the variety of tulip planted. It is also able to endure exceptionally cold spring weather and in fact blooms better with cool temperatures.
Our climate in Wisconsin is well suited to growing this hardy bulb as it actually needs the cold winter weather to induce the spring bloom. The bulbs should be planted in late September or October. Bulbs that are not planted cannot be held over to plant outside the following year, but instead can be forced to grow inside. The potted flowering tulip plants that are now available have been grown this way. If you decide to try this, remember that a tulip bulb would need a cold period in order to bloom. Never store bulbs in a refrigerator with apples. Apples produce a large amount of ethylene, a natural ripening hormone that is deadly to tulips.
A tulip bulb is a storehouse of carbohydrates. This food source is often used up during the blooming period. After a tulip is done blooming, the seed head at the top of the flower stalk should be snapped off so that energy is not directed to seed production. Do not remove or cut off the tulip leaves until they have turned yellow. This may take from 4 to 6 weeks. During this time the leaves will be feeding the bulb for next year’s flower. The bulbs that will flower the following spring will actually be the daughter bulb of the current mother bulb. Be patient with this process. Sometimes the dying leaves can be hidden by planting annuals or perennials nearby. Bulbs that do not bloom are called “blind”. These bulbs may have been stored incorrectly or had a poor growing environment. Bulbs that are too small to flower often produce only one large strap like leaf.
Tulip bulbs will tolerate most soil types, although a soil rich in organic matter will provide optimum growth and flowering. When planting bulbs in the fall it is important to set the bulb at the correct soil depth. Bulbs are planted with the pointed side up at a depth of 6 to 8 inches from the top of the bulb. It is helpful to add a teaspoon of bone meal at the bottom of the planting hole before setting the tulip in the planting hole. The flattened base of the bulb is called the basal plate and this is where the roots will develop. Bone meal is high in phosphate which will feed the bulb as it sets roots in the soil. Tulip bulbs can also be fed after they bloom by using a 10-10-10 fertilizer which should be worked lightly into the soil surface.
Last year I had over 400 tulips in bloom. It was a spectacular sight. Tulips are undoubtedly one of my favorite flowers. Until next time… happy gardening!
Nina Binkley
UW Extension Master Gardener Volunteer
