Friday, July 6, 2012

What's Up With the Oaks?

Isn't this heat wave getting old?  That's a pretty poor question for what is at stake for the region as we now are classified as SEVERE drought.  EXTREME drought is the next category that Western Kansas and Southeastern Missouri are now experiencing.  It's painful to watch the important agricultural crops wither all around.  We are able to water most of the horticultural crops at Powell Gardens and our gardens are holding up well thanks to a hard working and committed horticulture staff.  Kudos to them!

I am surprised by how one group of native trees is handling the situation.  Oak trees are not withering but putting on NEW growth!

I first noticed the new growth on the two Bur Oaks (Quercus macrocarpa) on either side of the Horticulture Cabin where my office is.  See the bright new growth  in the above photo.  Bur Oak is pretty much the king of oak trees in Greater Kansas City growing to nearly 100 feet tall and wide but with very strong branches that laughed off the ice load of 2002's catastrophic ice storm.  It also produces large, almost golf ball sized acorns.

Then I noticed that virtually all the oaks in the Parking Lot Arboretum on the other side of the garden were doing the same thing.  See the bright yellow-green new foliage adorning this Chinkapin Oak (Quercus muhlenbergii).  Chinkapin oak I consider to be the quintessential oak of Kansas City as it once graced the regions bluffs including where downtown now stands.  Lewis & Clark described it there and you can see it in the magnificent mural of their described scene at the Anita Gorman Discovery Center.

Powell Gardens Parking Lot Arboretum contains 96 oak trees comprising 16 of Missouri and Kansas's 21 species of native oaks and virtually all of them are not just enduring the heat and drought but putting on new growth.    I noticed that the River Birches (Betula nigra) were shedding leaves to conserve water.

Does this mean anything?  Was it caused by conditions earlier in the season or do they know something we do not?  I would love to be an optimist and that they fortell a change in the weather pattern that would bring a monsoon flow and returning rains to the region.  Time will tell.  I can say that oaks are one tough tree once they are established so no wonder that they were the dominant tree in the region when the settlers first came here.

My friend Leah Berg said this reminds her of a talk by America's tree expert, Guy Sternberg on a recent talk for Gardener's Connect / Garden Center Association.  Guy explained a need to plant more heat resistant trees as our climate warms.  He recommended oaks for such and I sincerely concur.