Spring 2010 - Combating Aliens

By: Bill Reichenbach, Certified Arborist WI-0188A

Spring Newsletter in Adobe PDF format The news is full of troubling accounts of exotic species making inroads to our environment. Numerous foreign plants, insects, disease organisms and animals threaten our natural environment. Many of these organisms can become invasive, their populations growing quickly without natural controls from their place of origin. Some are perhaps only a nuisance, like the Asian lady beetle invading our homes in fall. However, many have the potential to wreak havoc on our natural environment. The emerald ash borer, zebra mussel, and Asian carp, come to mind. These exotics have the ability to change the face of our landscapes. Their costs will be huge, and not just in the dollars spent trying to contain their spread.

It often seems that, as individual’s, we are helpless to do anything to change the outcome of these invasions. We are left to letting government agencies and private environmental/ conservation groups battle these threats to our environment. However, there are invasive plants in most of our home landscapes that you can do something about. Buckthorn, honeysuckle and garlic mustard have been invasive in southeast Wisconsin for decades. These weedy plants grow in various habitats in our residential landscapes and natural areas. They often take over large areas if left unchecked, outcompeting desirable landscape plants and native vegetation.

Buckthorn and honeysuckle are very adaptable woody weeds that can ruin your landscape’s aesthetic appeal. They are controllable! Larger plants need to be cut down and their stumps treated with an appropriate herbicide to eliminate resprouting. Smaller plants can be pulled or sprayed with herbicides. A key control component is to cover disturbed or open soil with mulch; exposed soil is ripe for weed growth. Also, plan to introduce new plantings which are appropriate for the site in newly cleared areas.

Garlic mustard is equally insidious and can envelop large areas, smothering desirable vegetation. Timing is everything when controlling this plant. The key is to not let the secondyear plants go to seed. Spraying a glyphosate-based herbicide in early spring and/or late fall is the best strategy. Any plants missed should be pulled (see Winter 2009 article).

All three of these plants have seeds that are constantly being dispersed and can lay dormant in the soil for years. Controlling them is an ongoing war, but we can win battles. If you have large infested areas, plan to attack manageable-sized sections, one at a time. Get started and stay at it. It gets easier over time. These plants do not know boundary lines. Communicate with neighbors and friends about the problems these plants cause; work as a neighborhood to control them.

Wachtel’s staff is eager to help you in the fight. We have the staff, tools and knowledge to make a difference on your property. While buckthorn and honeysuckle can be battled any time, garlic mustard is more timing-sensitive – call us early in spring.

© Copyright 2009 – Wachtel Tree Science & Service, Inc.

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