Writing on the MSU Extension web site this week, ACS member Dr. Bert Cregg of the Department of Horticulture & Department of Forestry at Michigan State University is positing that the central region is likely to see heavy cone production this year as a result of last year’s drought. While most conifer enthusiasts, attracted by the bright colors of the cones in some species, are sure to rejoice, the average homeowner is likely to resent having to wash their cars more often and hose off their walkways to get rid of all the pollen.
Interestingly, Cregg points out that Spruces, firs and Douglas firs have a two-year cone production cycle. As an evolutional adaptation to reduce self-pollination, female cones are usually produced in the upper one-third of the tree crown, whereas pollen cones are mostly found in the middle one-third. Reproductive buds are formed in the summer of the first year and then flush in the second year. So, the outbreak of pollen cones we’re seeing this year is related to environmental signals the trees received last summer.