Special thanks to Eve Blanchard for providing her time and expertise in responding to your questions below.
Q: I built a solarium on to my house and it shades the area my yellow Darwin tulips are planted in. Only 1 or 2 of the 6 of them have emerged, although all my other tulips are up (those not planted in shade). These tulips have bloomed marvelously for the past 2 springs and emerged in February the past 2 years. Is it possible they will still come up and bloom, or should I plan to dig the bulbs and move them to a full-sun area for next year, or are they doomed if they don't come up? I think they bloomed in early May the past 2 years. The area does get some late afternoon sun, but not too much. If I should dig them up, when would be the best time to do so? I hate to lose them. They are my favorite.
It's possible that something other than the amount of sunlight (and
thus soil warmth) has affected your bulbs. For instance, moles or
other creatures may have eaten them, or they may be diseased. A lack
of sunlight may have kept your soil cool enough that the bulbs are
delayed, but this sounds like an awfully long delay. If the soil was
both cool and wet, the bulbs may have rotted. Once they've emerged,
tulips can do fine in partial shade, particularly if they receive
afternoon sun, but they will not thrive in full shade.
A: Great question about positioning a mirror to reflect sunlight onto the soil where your tulips are planted! Why not experiment with that? Researchers have had some success conducting that sort of experiment with forage grasses. If your plot receives no sunlight at all, it might be difficult to reflect sun onto it. Do let us know the results of your experiment!
George Mason Elementary School
Q: Some of our tulips have extremely short stems this year. At least the few that have already bloomed. However, some that only have the beginnings of buds have much longer stems. I know they are all the same species, so why is this true?
Now that's a puzzle! Temperatures during certain times in a tulip's
development will affect stem length. Tulip bulbs need a certain amount
of time in cold temperatures in order to release certain growth hormones.
(This happens naturally during the winter.) These hormones will cause
the emerging flower stems to lengthen. But if bulbs are planted too
late in the fall, or experience a warm spell in winter, they may not
have enough chilling time. In that case, the resulting plants may
have short stems. On the other hand, a long period of cold weather
before bulbs emerge in the spring can have the opposite effect: A
"stressed" stem might actually grow longer. This could also
happen if temperatures get very warm as the tulip plant grows. Stems
that lengthen due to the stresss of too little or too much heat may
not be as sturdy as stems on healthier plants. Another factor -- poor
root development caused by heavy soil or lack of rain -- could result
in short stems.
Terra Centre Elementary
Q: Our class was wondering how do tulips get their colors? How do people tell what color the bulbs are when they package them?
A: Just like you and your classmates have different hair colors, tulips growing in the wild have different petal colors. Perhaps they attract different types of pollinators. People who breed tulips for gardens also use different methods to propagate (create new) tulips with a variety of colors. Here's one method: When a breeder moves pollen from a tulip flower of one color to a tulip flower of another color, the second flower is fertilized. The seeds it produces are then planted. It will take 5 or 10 years for the tulips grown from those seeds to produce flowers. The flowers will be a new color or colors. If it's a "good" color, growers can create lots of new bulbs to sell by saving and growing the offsets (small new bulbs) that the tulips will produce each year. This is called "asexual" reproduction. It produces new plants that are exactly like the parent plants. Sometimes after a few years, the offsets from one tulip parent will naturally change color. They might even produce multi-colored offspring!
People who grow tulips commercially carefully label the plants and bulbs by type (cultivar) and color. That way, people who package them know which ones to pick out and pack!Q: Our tulips are blooming right now. We noticed that the tips of the leaves have a red color to them. Is this because our tulips are red? Would white tulips have white around the edges of their leaves?
A: Great question and observation! If you are talking about the main tulip leaves, the red color is not likely related to the flower color. Tulip leaves actually have a red pigment in their tissues all along. But it is masked by the green chlorophyll that plants need to make food during photosynthesis. If a tulip plant is under any kind of stress, such as cold temperatures when it emerges, the chlorophyll may begin to disappear from parts of the leaves. That allows the red to show through. (The same kind of thing happens to trees in the autumn when their food-making begins to shut down for the season.)
If you are instead talking about the modified leaves that surround and protect the flower buds (called sepals), I have a different answer! As the bud stretches its tip and becomes larger, the green sepals do take on the color of the tulip flower. When it's fully open, it's hard to tell that the sepals were once green!
A: Just as some students in your class are taller than others, wild tulips also vary. Plant breeders can also produce tulips with different length stems.
are some other factors that can influence tulip height once they've
Mill Run Elementary School
Q: Why are the tops of the tulip leaves and the center sprout shriveled and brown instead of a healthy green?
A: It sounds like your early-emerging buds may have got frozen. Tulips can withstand snow and even cold temperatures. But if the flower buds have poked up, and the temperature drops to around 20 degrees F, the buds and leaves could be damaged. If that happens, blooms would not likely appear. This sometimes happens when a warm spell (which causes bulbs to emerge) is followed by a cold snap. Does that describe what happened in your garden? If not, it's possible that they may be diseased.
A: It's not likely that the spray damaged your tulips. Most commercial deer and rabbit sprays are meant to be used on plants. Because you didn't describe how your students are damaged, I can't evaluate what might have happened to them.
From: The Long Eaton School - Derbyshire, Nottingham, UK
Q: "Our tulips have bloomed, they look lovely, but can anyone tell me why the tulips that we have planted over the past 3 years bloomed a lot earlier?"
Well, a number of factors could be at work. For instance, you might
have different temperatures, sunlight, soil type, or other conditions
that vary where each group of tulips is planted. Did you notice that
the late-emerging tulips were in one section of your garden? If they
were in the shade, they would have received less sunlight than the
others. So it would have taken longer for the soil to thaw out, dry
out, and warm up. If one group of tulips were in heavy, wet soil,
they might also be slow to bloom.
Expert, Eve Blanchard