Is IBDU a good choice for winterizing turf? — Via the internet.

It depends on what you mean by “winterizing,” a term thrown around a lot, usually without any accompanying definition of exactly what that means. IBDU, and most other slow-release fertilizers, work well for early to mid-fall fertilization. Turf at this time is still actively growing and still has enough growing time left in the season to utilize most of the nitrogen that will be releasing from the slow-release product over the following month or two.

Late-fall fertilization contrasts from fertilizations earlier in the fall because turf at this time is no longer undergoing active shoot growth. It is, however, still photosynthesizing. Fertilization at this time aids photosynthesis and production of carbohydrates, and these are stored rather than put to use in new growth. This increases winter hardiness as well as earlier spring greenup and vigor the following year.

For late-fall fertilization, a quick-release form of nitrogen is best. The remaining days and weeks when photosynthesis is possible may be few (especially in colder regions) so the extended release pattern of slow-release products may be of little use (until the following spring). That's why urea is a common late-fall fertilizer (plus, it's inexpensive).

Some don't like it hot

Why not plant bulbs in the summer? They say this can make the bulbs rot in the ground, but why is that, when they seem to oversummer just fine after they get established? — Via the internet.

The reason is that well-rooted (i.e. established) bulbs are more resistant to diseases. Warm, moist soil may be more conducive to certain diseases, but a well-established plant can usually resist them well enough.

David Caras, associate director of the Netherland Flower Bulb Information Center, explains that “Early planting is not recommended because newly planted bulbs need time to develop strong root systems, which is best done when conditions are optimal. The cooler soil of mid-Autumn allows the bulbs to root and establish themselves during a period less conducive to fungus and other problems that thrive in warmer soil conditions.”

Although established naturalized or perennialized bulbs usually oversummer with little difficulty, Caras offers a precaution. “For most naturalized bulbs, two other things to watch for over summer are overwatering and too much fertilizer. That's why overplanting naturalized beds with annuals that are then watered and fed throughout the season can sometimes cause naturalized bulbs to perform poorly.”

Praying for rain?

I read recently that some trees turn their leaves up before it rains. Any truth to this? How would this work? — Via the internet.

I have run across several references to this phenomenon. It is an old belief and one that still is reported anecdotally. Poplars and maples are commonly associated with this, supposedly showing their silvery undersides in advance of impending rain.

However, I can find no research-based literature on the subject. Several university arborists I asked were familiar with the notion, but none knew of any research that supported or explained it. Thus, I cannot answer your question with any concrete information. If any of our readers has more information about this, we would like to hear from you.

Eric Liskey has a bachelor's degree in ornamental horticulture and a master's degree in botany. He has been licensed for pesticide advising and applications in California and Missouri, and has more than 10 years combined professional experience in landscape installation and maintenance, nursery retailing, pest management and botany.

If you have a question about landscape or turf management, write to “Researching Maintenance,” Grounds Maintenance, P.O. Box 12901, Overland Park, KS 66282-2901, or send you question by e-mail to

Questions are selected on the basis of current general interest. Unfortunately, we are unable to guarantee a response to individual letters.

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