In the GARDEN
Surprise blooms and bee-ing careful
Q: I discovered this among my daffodils when I raked leaves. I don’t remember ever seeing it before and didn’t plant it.
A: I think it is an old hyacinth that is trying to make a comeback. Hyacinth bulbs will produce smaller flower heads with fewer individual blooms if they age without proper care and nutrition. It is also possible that it is a seedling-grown bulb that is just coming of age to bloom. Fertilize it and allow the foliage to grow for at least six weeks after bloom. If you think it would be better in another flower bed, you can dig it up after the six weeks and replant in the new location or dry the bulb and plant in the fall. With good nutrition, hopefully the flower head will be larger each year. The color is stunning. ‘Bee’ conscious of how pesticides affect pollinators
Q: Crape myrtle bark scale disease is ruining trees all over Arkansas. A soil drench using Bayer Tree and Shrub Protect and Feed containing Imidacloprid has been recommended, but many beekeepers are avidly against using imidacloprid. I called Bayer, and they assured me the product was safe for bees in the concentrations used and applied as directed. I also mentioned that bees regularly feed on the flowers. What are your thoughts concerning this product? Have there been any studies that support the beekeepers’ concerns?
A: Insecticides containing imidacloprid and other systemics have been raising a lot of concerns and questions in the past 10 years. I went to the authority on bees in Arkansas, Jon Zawislak, who is the apiculture specialist for the University of Arkansas Division of Agriculture.
Here is his response: “Crape myrtles are interesting plants. They don’t produce much (if any) nectar to attract bees, but they do produce two kinds of pollen. One type serves as the plant’s reproductive pollen, which bees transport, and the other is a ‘feed pollen’ that is essentially offered to bees as a reward for visiting, but
cannot fertilize another crape myrtle.
“Your question was about whether a systemic neonic is potentially harmful to pollinators. This is a common question I get, but I’m afraid the answer is not straightforward.
“With any pesticide product, the dose makes the poison, and labeled insecticide application rates for ornamental plants are much higher per plant than the same ingredients in crop systems. Imidacloprid does appear to be one of the most effective tools to combat crape myrtle bark scales, because it stays present and has longer residual action on phloem-feeding pests, as opposed to trunk applications that may not last as long because they work only when they contact the scale insects.
“One study conducted at Auburn University found honey bees and other pollinators to be frequent visitors to crape myrtle. The same study determined that all residue concentrations found in tested pollen were high enough to harm visiting honey bees, regardless of the timing of product application (etd.auburn.edu/
handle/10415/7059).
“Just exactly how harmful these products are to pollinators depends on how much, and how often, bees are exposed to these chemicals. In a large landscape, not every flower is a treated crape myrtle. And honey bee colonies will be foraging on many plant sources simultaneously, which minimizes the risk of toxicity from a few isolated trees.
“As an urban beekeeper myself, this is a risk I have to accept and understand that the potential harm to my bees done by a nearby homeowner treating a few infested trees may be a negligible drop in the bucket when compared to the value the homeowner places on the health of those trees. It’s unlikely to cause significant harm to my honey bees, but the potential risk certainly does exist.
“Bumble bees and native solitary bees are more likely to be exposed to higher risk, as they are more sensitive to neonicotinoids than honey bees. Generally speaking, yes, all insecticide products pose a risk to pollinators. And judicious use of these products is recommended,
at the lowest effective application rates. The consensus of many scientists is that habitat loss is a greater problem for pollinators.
“Plant more flowers! Having more floral resources in the landscape all season will help mitigate the effects of a few treated crape myrtles.”
BACK TO JANET: The product is effective, and if yours is a valuable tree, this is the best method of control. However, don’t take the mindset that if a little bit is good, more is better. Apply at the recommended rates and only as needed. Don’t treat every crape myrtle in your yard, just those that are affected.
Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas’ best known horticulture experts. Her blog is at arkansasonline. com/planitjanet. Write to her at P.O. Box 2221, Little Rock, AR 72203 or email jcarson@arkansasonline.com.