Perhaps some tire of my frequent articles on the Emerald Ash Borer that is bearing down on Central Iowa. My cause is simply to make all aware of what we are facing. Check the species of trees in your yard, or along your street or throughout your community and rural area. If they’re black, white or green ash trees, their years are numbered. Remember, there is no known cure for an infected tree, for once the exotic insect pest has entered the tree through the bark, the cambium will be encroached by the larvae, and girdling and irreversible damage with death to the tree is inevitable.
On Monday I drove to Fairfield and Burlington to observe the onset of eventual devastation of these three species of trees, which tend to make up the majority of shade trees that were planted following the Dutch Elm disaster of forty years ago. In Fairfield, I could pick out the ones where vitality was compromised and advanced color change in the upper canopy foliage was evident. It was fairly easy to discern the healthy ash trees from the infected. In Burlington, it was an advanced story. The city has already been declared “infested,” and in certain parts of the community ash trees had been removed, or were marked for removal, and foliage vitality was such that the insect pest had already done its job on many I observed. No ash tree in the nation is immune from this scourge that probably made its way to America from Asia inside the wood of shipping crates.
If you have ash trees, be proactive in their replacement. Unless a biological or chemical cure miraculously occurs, the trees are most likely doomed. The best that can be done is to enjoy the ash while it remains healthy, but start planning and planting replacements as soon as possible. Why not yet this fall? Or, no later than next spring.
A plethora of shade tree species exist that you can plant now, and have a head start when the Emerald Ash Borer hits your yard. Encourage the city to do the same. I will not suggest who you purchase your trees from, but there are many private nurseries where you can obtain quality specimens in plastic containers or “balled and burlapped.” Key to the survival of new plantings is to dig a hole at least twice the size of the contained root system. Fill the hole with water to the surface, allowing it to entirely seep into the soil. Do that a couple of times to thoroughly saturate the site, and only then remove the tree from the canister, untangle the compacted and cramped root system for aeration, and then spread the roots evenly throughout the hole while having someone back-fill with the granulated soil.
Your nursery person will be a valuable help in species suggestion and planting methods. But, above all else, no more monoculture! Select a variety of shade species, giving diversity to your yard and reducing the chance of another single-specie planting being wiped out by some yet unforeseen insect or pathogen.
Any questions or comments, e-mail me at firstname.lastname@example.org, or call (515) 975-8608.