Creating Diversity in our Urban Forests

Communities that have lots of trees are more appealing, have cleaner air, lower costs for heating and cooling, higher property value, and more wildlife.  Unfortunately, the health of many urban forests is threatened by a lack of diversity in the varieties of trees that have been planted.

Even after the very sad loss of millions of American Elms which had been over planted,  communities, developers, and private property owners have repeated mistakes of the past by over planting  too many ash and maple trees over the last fifty years.  The result is many urban forests that lack diversity and are vulnerable to another major tree die off.  This time the most immediate threat comes from the Emerald Ash borer.

Emerald Ash borers have devastated large swaths of Michigan and  Indiana,  killing 90% or more of the Ash trees in some communities in as little as five or six years once the insect become widespread.  Emerald Ash borer is now is a few counties of Minnesota.

The solution to the problem of mass die off of urban trees is to plant with far more varieties of trees from a far greater number of species and genera.   At Knecht’s Nurseries we currently sell trees from 43 different genera, but the maple (acer) genus represents about 40% of the trees we sell.

The reason for this imbalance is simple.  People love maple trees.  Our customers see the beauty of maple trees, plant them and soon some of their neighbors are wanting a maple tree.  It’s just human nature.  We all have tendencies to make buying decisions in this fashion, and the result is a lack of diversity in the urban forest is the result.

To over come the imbalance, we will need to adapt a deliberate strategy of planting a much wider variety of trees.  Start by taking a look at the 42 genera of treesJapanese Tree Lilac we currently stock at Knecht’s Nurseries.  I hope this list gets your imagination going!