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.

Losing an Oak Tree Friend

I was saddened to see the old Swamp White Oak (Quercus bicolor) tree at the end of the walk to the Chapel has passed. We were hoping the tree would resprout from its hollow shell but it continued its slow decline. Oaks like this can grow for 100 years, live for 100 years, decline for 100 years and die over another 100 years.

Looking out the front doors of the chapel, past the Fay Jones fountain, this classic oak with its unique cavities of age was always a thing of beauty--the type that comes from experience, age and imperfections.


Senior Gardener Janet Heter (depicted) said: "It's like losing an old friend." I recall the writings of America's great conservationist, Aldo Leopold in A Sand County Almanac; especially his phrase another "funeral of our flora" as original native plants are lost. Did this tree experience the buggling of Elk? A stampede of Bison? The rush of wind beneath a massive flock of Passenger Pigeons? (all creatures long gone)

I also recalled Robert Hillier's poem A Pastoral with the orchard man declaring "this empty shell must go;" but we've always defied this showy "veteran's" removal. We will have to remove most of the tree's trunk for visitor safety reasons but we will save as much of the trunk as possible. Look for a new Flowering Dogwood (Cornus florida) planted in the tree's cavity and a young Swamp White Oak planted nearby to continue its kind.


We have 6-foot seedling Swamp White Oaks in our nursery grown from acorns of our wild trees. One or more of these will be transplanted beneath the old oak's trunk.


Swamp White Oaks are the dominant native tree at Powell Gardens; a few trees are older than settlement (at least 150 years old). This image of its leaf shows the unique lighter underside. The botanical name is "bicolor" because the leaves are dark green above and whitish beneath, creating "two colors." The fact that Swamp White Oaks are the king of trees here at Powell Gardens is very unique: it describes our very poorly drained clay soils. In most areas of the Midwest where this tree grows, it is found in floodplains and swamps (here it grows on the hills!). It is also interesting we are less than 10 miles from the western edge of its native range, the tree is absent in the wild west of Lone Jack.


Oaks are the most important wildlife tree throughout their range. Their nutritious acorns are a staple of many birds, deer, bear, etc. Even our young oaks in the nursery are already producing acorns. Swamp White Oak acorns are always on a characteristic stem. They share this trait with their first cousin on the other side of the Earth: the English Oak (Quercus robur). Oaks are considered the tree that enabled us to create our civilized society: to learn more read Oak, The Frame of Civilization. They are the official tree of the United States of America.

Remember to plant and replant oaks wherever you can. From tiny acorns, mighty oaks grow!