If you have an opportunity to stroll around your property and quickly became discouraged because it looks like a jungle out there, take heart. Fall and winter are a great time to control invasive plants and get a jump on managing them for next year.
Before I get too far into invasive management techniques, let’s define our terms. According to the USDA:
An “invasive species” is defined as a species that is…
- Non-native (or alien) to the ecosystem under consideration; and,
- Whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
(BTW, The proper horticultural terms for aggressive native plants are “thugs” or “bullies”)
Advantages to Fall & Winter Control
Some plants are very easy to identify and locate during cold weather months. For instance, honeysuckle shrubs (Lonicera maackii, L. morrowii, and L. tatarica) stand out because they are some of the last shrubs to drop leaves in fall. Their shaggy bark and red, shiny berries are other distinguishing features.
Identify Multiflora rose (Rosa multiflora) by its green stems in winter. Target it for control in seasons when it is easy to spot and leaves have dropped.
Control Invasive Plants When There is Easier Access
Impenetrable thickets become manageable after leaves drop, making it easier to control invasive plants. Some areas are only passible in fall and winter, so take advantage of the season.
Take Advantage of Invasive Plant Attributes
Some invasive plants, such as English Ivy (Hedera helix) remain evergreen while many native groundcover plants are dormant. This may be an opportunity for mechanical removal or an herbicide application to gain control of large infestations.
Cutting deciduous vines like porcelain berry and oriental bittersweet will look unsightly if cut when they have leaves
You may be able to request special pricing for large winter projects if your landscape company is especially slow at this time of year.
Additional Tips to Control Invasive Plants
Know Your Invasive Plants
Just because you buy a plant at a garden center, doesn’t mean it isn’t invasive. Believe it or not, plants such as Japanese barberry (Berberis thunbergii) are both on the PA invasive plant list and readily available for purchase. Japanese barberry has recently been identified by the Pennsylvania Department of Agriculture as a noxious weed, but may still be found on nursery shelves until the fall of 2023.
Other Invasive Landscape Plants
Control Invasive Plants One Species at a Time
On my own property, I often try to control one invasive species at a time. I find it easier to get rid of all Wineberry (Rubus phoenicolasius) for example, rather than every invasive plant on three acres. The additional benefit of this approach is that control becomes easier since it is no longer spreading from within the property lines.
It may take several years to get control of an unwanted species if there is a seed bank present. Invasive plants will re-establish themselves given the opportunity, so once you remove a species, keep it out by continued monitoring and control.
Disturbed soil is an opportunity for invasive plants to become established. Make sure soil is covered with mulch and disturbed areas are monitored.
Timing is Important
If you can disrupt the life cycle of a species, you will be much more effective and reduce the amount of work required to gain control. For instance, bush honeysuckle’s berries ripen in the fall. Removing the plant before this happens keeps these berries from becoming next year’s unwanted shrubs.
Fill Empty Spaces
The easiest way to keep invasive species out is to fill your property with desirable ones. Replace bush honeysuckle, burning bush, and multiflora rose with native viburnums, rhododendrons, and bottlebrush buckeye. Replace Norway maples with Sugar maples or other native trees. This approach takes opportunities away from invasive species, and improves the ecological function of your property.
Although there is almost always something to do in the garden, fall and winter can be a bit slower. So take advantage of the season and use the cooler weather to manage invasive plants on your property. And of course, contact us if you would like help!