Winter is the Perfect Time to Manage Invasives

Are you counting the days until you can get outside and work in your yard? Well, wait no longer. Winter is the perfect time to identify and manage many invasive plants. 

National Invasive Species Awareness Week is February 23–27. The Newtown Knotweed Initiative and the Conservation Commission will have informational tables set up in the Community Center and the municipal building February 17–March 6 with handouts and live specimens for identification.

Invasive plants are easier to locate in winter because surrounding foliage has died back, making them more accessible. Ticks are less active in cold temperatures and cold weather makes wearing long sleeves and pants welcoming as compared to 95 degrees one might experience in August.

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Prioritizing your invasive work helps one focus for allotted resources. Look for vines choking native trees. Invasive vines like Oriental Bittersweet are easily tackled in the colder months. This time of year, bittersweet may still have a few red and orange berries and its bright orange roots are a dead giveaway. English Ivy, an evergreen, is very noticeable now. Aerial rootlets along the vine hold fast to bark. Removing at least a one-foot section of this vine is necessary to ensure that rootlets cannot re-attach to the trunk.

A good technique for managing vines is to remove a section with a cut about 12 inches off the ground and as far up as you can safely reach. Resist the urge to pull remaining vines out of the tree for your safety and to prevent tree damage. As long as temperatures are above 45 degrees and the ground is not frozen, you can paint the remaining stump with an herbicide. Painting must be done within minutes or the cut will seal over and prevent absorption of the herbicide. Re-cutting the stump later to apply herbicide is another option. 

If the ground is not frozen, invasive shrubs can be dug out. Shrubs like Japanese Barberry can be cut back now so there is less to do in spring and summer.  Accessing invasive shrubs now is so much easier than in the growing season. Barberry is a very thorny shrub with red elongated berries. Cut stems reveal bright yellow color. Multiflora Rose has downward curved thorns like a cat's claws and may still contain a rose hip or two. Burning Bush is easily identified by winged stems and red berries and this shrub can grow to 15 feet. This time of year, shrubs can be cut to 6 inches above the ground and the stumps immediately painted with herbicide as long as temps are above 45 degrees.

Basal bark painting is another option for invasive shrubs. The herbicide is mixed with an oil carrier to penetrate the bark. The trunk is painted at ground level to 12-24 inches. This method uses less herbicide compared to foliar spraying which uses much more herbicide and is very harmful to beneficial insects.

Invasive trees can be addressed this time of year as well. Invasive Tree of Heaven can be treated with herbicide using basal bark or hack and squirt methods. Once again, temperatures need to be above 45 degrees and the ground unfrozen. If you are unsure about the identification of a tree, you can always tag it with colored tape until definitive identification can be done in spring. Plant identification apps like LeafSnap or Seek by iNaturalist can be helpful. Tagging a treated tree will remind you to circle back in the spring to see if a second treatment is needed. 

Disposal
Never dispose of invasive plants with berries in compost or yard waste. Branches with berries should be bagged and disposed of in the trash. Or, you can also designate an area for a “die-and-dry” pile. Simply construct a sturdy base with your thickest branches, layering more branches on top. Be careful not to allow the root balls to touch the soil. Your invasive pile(s) should be monitored for any regrowth. Placing invasives on a tarp is another option.

Take before-and-after pictures. Doing so will help motivate you and allow you to measure your progress. Even if you don’t have a lot of extra time, tackling one tree or shrub on a weekend day or committing just a few minutes each week will lead to tangible progress. So, grab your coat and get outside to turn the tide against invasive plants in your yard.

The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org