Caring for Your Sugar Woods Part 3: Removing Invasive Species

August 9, 2019

When setting out to remove invasive species, bring loppers, a hand saw, burlap, twine, a handcart, and a good-natured assistant!

Little boy next to wheel barrowIt was a little while ago when, inspired by a talk by one of Vermont’s county foresters, we started this series of blog posts about how ordinary landowners can care for their sugar woods in a changing climate.

Since then, we have covered mapping invasive species and cultivating an ideal suite of tree species. That leaves removing invasive species and protecting riparian buffers and other critter habitat. We’ll cover the former today, and the latter very soon.

You may recall that among the peskiest invasive species in sugar country are buckthornhoneysuckle, and barberry, all three of which we found in our own woods over the summer. According to the Nature Conservancy, the best time to remove at least two of the three is fall, so we stayed our hand until now.

Thankfully, this delay gave us time to connect with Emily Seifert, a naturalist who spent several years as a Stewardship Manager for the Nature Conservancy, managing nature preserves by, among other things, monitoring and removing invasive species from the land. Emily knows a lot about the woody plants that have invaded the forests of sugar country, how to identify them, and how to safely remove them, so one cool morning, we set out on the homestead with our invasive map to have a look.

We are proud to report that Emily confirmed that we had correctly identified our invasives in all instances! Huzzah! We have not lead you astray! While you are likely to find, like we did, that honeysuckle and barberry are easy to identify, buckthorn is harder, and we are more than a little impressed with ourselves that we got it right. As we’ve discussed, mature plants will have fairly recognizable blue berries in late summer and early fall, but at other times of the year, and for immature plants, you have to really concentrate on leaf shape, color, and position. Emily recognized even our immature buckthorn immediately as such, of course, but passed along these hints for beginners: the underside of buckthorn bark is  bright orange and even the immature plants may sport a thorn or two.

From left to right: the bright-orange insides of buckthorn bark, a buckthorn thorn where two twigs meet on a mature tree (to the left of the lower index finger), and the brown, hollow insides of an invasive honeysuckle stem.

Emily also taught us how to check to make sure that the honeysuckle on our property was invasive, as opposed to the native variety out there. It was. How did Emily know? The inside of the stem of an invasive honeysuckle is hollow and brown.

Having passed identification with flying colors, it was now time for removal and disposal. Emily agreed that it was best to remove invasive plants from the ground in their entirety – roots and all – as long as the infestation covers a modest surface area. (Root removal of infestations that cover a large surface area can leave bare ground ripe for other invasives to take root. Such removal on steep slopes can lead to soil erosion.) Emily said that for mature plants, however, cutting and covering with black plastic or a double layer of burlap was a respectable, next-best method. When pulling, Emily noted, it is important to get the entire root system as these plants propagate from the roots. Complete covering of all above-ground parts of the plant is necessary for the same reason, she said. Other notes? Pat yourself on the back for punctuality! Early detection and removal is key to controlling invasives!

We ended up using both methods. While we were able to pull up all of our honeysuckle, most of our barberry, and our immature buckthorns by the root, the roots of one barberry bush and our mature buckthorn tree weren’t budging. So we lopped or sawed them off as close to the ground as possible, and covered with a double layer of burlap, tied on with twine or staked down with sticks. Our intent is to pull our map out and monitor those areas each spring and fall to ensure that our removal was complete and our covers stay in place.

From left to right: a “Charlie Brown” white pine has been replanted where an invasive shrub honeysuckle was pulled out by the roots, and a mature buckthorn is cut down and covered to discourage re-sprouting.

Emily reassured us that bagging our invasives and bringing them to the dump was not necessary, as we had feared it would be, and was, in fact, a last-resort method. And, while it doesn’t seem to be in any of the literature on safe disposal of invasives, she agreed that destroying these woody weeds in a bonfire – our plan – was probably fine. Emily did caution us against taking the invasives off-site – in Vermont it is actually illegal to do so unless you really know what you are doing – and noted that composting invasives can result in more infestations if not done according to certain best practices.

​So – taking care not to spread berries around as we went – another one of Emily’s tips – we loaded our invasives into a garden cart, wheeled them to the fire circle, and had ourselves a campfire. Our efforts resulted not only in potentially healthier sugar woods, but also a sugar woods that is easier to navigate – honeysuckle and barberry can get so thick they make the woods hard to traverse – and less prone to tick infestation. According to Emily, studies show that dense barberry infestations give cover to carriers of ticks and thus can result in higher tick populations. Not only that, but, in the long run, our sugar maples now have a better chance of reproducing now that they aren’t competing with a thick carpet of invasives.

​So, with a little more hope, and a little more connection to the land than we had before, we look forward to learning more soon and passing it right along to you in our fourth and final installment on caring for your sugar woods: protecting riparian buffers and other critter habitat.


Invasive honeysuckle, barberry and buckthorn, getting ready to go up in flames at the family fire circle.
Invasive honeysuckle, barberry and buckthorn, getting ready to go up in flames at the family fire circle.