Jeremy Siegel: This is GBH's Morning Edition. Taking care of a garden is a lot of work, and it gets even harder when you have something actively working against you. I'm talking about invasive species: Plants and insects that can destroy your work outdoors. So how can we keep unwanted invasions at bay? And is there any situation where a new species overtaking your garden could actually be welcome news? Here to answer those questions and more is GBH meteorologist and gardening expert Dave Epstein with his weekly deep dive into the science behind the weather and the garden. Dave, good to see you.
Dave Epstein: Good to be here.
Siegel: So what exactly do we mean when we use the phrase invasive species?
Epstein: Yeah. So invasive species are something that's been introduced to an area. It becomes established. In other words, it just grows on its own pretty easily. And it can cause pretty serious ecological or even economic harm if it's something that maybe attacks one of our crops, like something that would come in and, I'm making this up, attack the apple crop in Massachusetts, right? So that would be a problem.
Siegel: So as time goes by, we hear about different kinds of invasive plants and insects attacking different plants. Is there anything this year that you're specifically keeping an eye on?
Epstein: I mean, there's so many different invasive things that are out there. You know, Mass Audubon, for example, has good stuff on their website that has a list of them. Native Plant Trust, which is out in Framingham, also has some really great resources. But, you know, some of the more, I guess, aggressive ones: Oriental bittersweet. That stuff comes up. That's what you see kind of on the side of the road, wrapping around trees, especially in the fall, because in the fall it gets those berries. And it was actually introduced because florists loved the berries and putting it in arrangements. And now it's spread everywhere. The birds eat it and they spread it, after pooping out everywhere. Multiflora Rose is a real problem. We even have kudzu in Massachusetts in a few spots. Barberry is a problem. Buckthorn is something that I've got in the backyard that I'm constantly pulling out. That can be a problem. Garlic mustard is flowering right now. You might see that along the side of the road. It's got little teeny white flowers. It's actually edible, so you can eat it. But that's another one. Phragmites in the wetlands. The common Phragmites is a problem. So there's a lot of things out.
Siegel: There that is a long list, and I imagine each of them have their own properties that make dealing with them difficult. Do you have any across the board or specific strategies for getting rid of invasive species ruining your garden?
Epstein: Yeah, I mean, ripping stuff out by hand and kind of walking around your garden to see if you have any of these things coming in and getting rid of them before they really take over is one method that I like. So, just yesterday, actually, I was in a little area of the garden and I noticed some very tiny garlic mustard seeds seedlings coming up. So I was ripping those out because I don't want it to become established. Once it flowers, those flowers produce tons of seeds. So that's one way. Also, if you notice something like, you know, one of the vines coming up, to try to get that out by the root, really not letting it become established with the Oriental bittersweet, for example. If something's really established, you can, you know, dig it out. It takes a long time. You can also use herbicides, depending on the particular invasive species. But again, you don't want to be spraying herbicide all over the place. So I tend to recommend cutting it back to the ground, painting on a little bit of herbicide on some of these things, which will hopefully keep it at bay. You can also look online. There's all sorts of other methods. You can smother it. Heat the soil up, etc. etc.
Siegel: This whole conversation has centered on these species being a bad thing and how we can get rid of them, but are there any invasive plants or insects that are welcomed or even helpful in any way at all?
Epstein: Yeah, so we want to use a different term for those things. Let's call them aggressive, right? So aggressive would be a term I would use for things that are native that have invasive-like tendencies, but they're native. So an example would be hayscented fern. So you want something to take over in a shady area of the garden, you put in hayscented fern, it becomes established. That stuff's going to spread everywhere. It's going to smother out everything. But it's a native plant. Mayapple would be another one. I've got some patches of mayapple in the backyard here that are in the woods, that there's nothing else that's growing there because they're so aggressive. But it's a native plant. So you want to try — and again, that's where I go back to Native Plant Trust, or the Audubon Society or some of these other, some of the other nurseries. You know, you have folks who are experts to say, hey, I want something native that's aggressive, that's going to just take over a certain area. But you have to know, just like with something that is invasive, it can become a problem, even a native plant, if you have a garden that you need managed.
Siegel: That is meteorologist Dave Epstein with his weekly deep dive into the science behind the weather and the garden. Thanks so much, Dave.
Epstein: You're welcome.
Siegel: This is GBH News.
Meteorologist Dave Epstein is our go-to person for pressing weather questions on everything from winter blizzards to summer droughts. He’s also a horticulturist, meaning he’s an expert in anything that grows leaves and flowers. GBH's Morning Edition asked our audience for weather and gardening questions, and Epstein graciously answered them on the air.
Have a gardening or weather question for meteorologist Dave Epstein? Tweet him @GrowingWisdom, email us at thewakeup@wgbh.org, or text 617-300-2008.
Taking care of a garden is a lot of work, and it gets even harder when you have something actively working against you, like invasive species: Plants and insects that can destroy your work outdoors.
So how can we keep unwanted invasions at bay? And is there any situation where a new species overtaking your garden could actually be welcome news? GBH meteorologist and gardening expert Dave Epstein broke it down for us.
What are invasive species?
The U.S. Department of Agriculture’s National Invasive Species Information Center defines them as a non-native species — animal, plant or microbe — “whose introduction causes or is likely to cause economic or environmental harm or harm to human health.”
“In other words, it just grows on its own pretty easily. And it can cause pretty serious ecological or even economic harm if it's something that maybe attacks one of our crops,” Epstein said.
What are some common invasive species in the Boston area?
Here’s a non-exhaustive list:
Oriental bittersweet, a vine that grows on trees and can eventually uproot them because of its weight. “It was actually introduced because florists loved the berries and putting it in arrangements. And now it's spread everywhere,” Epstein said.
Multiflora Rose, a shrub that can grow thickly and crowd out native plants.
Kudzu, a vining, large-leafed legume more common in the South that has also been found in Massachusetts.
Buckthorn, a small tree that can crowd out native plants.
Garlic mustard, common on roadsides, grows with tiny white flowers. “It's actually edible,” Epstein said.
Phragmites, also known as common reeds, are prevalent in wetlands.
What are resources I can use to determine if a plant is invasive?
Epstein recommended referencing the Mass. Audubon list of common invasive plants in Massachusetts and Framingham’s Native Plant Trust.
So what can I do about it?
There’s not one definitive way to get rid of invasive plants, Epstein said, especially for people who want to do it without using herbicides that can also harm native plants.
“Ripping stuff out by hand and kind of walking around your garden to see if you have any of these things coming in and getting rid of them before they really take over is one method that I like,” Epstein said. “Just yesterday, actually, I was in a little area of the garden and I noticed some very tiny garlic mustard seeds seedlings coming up. So I was ripping those out because I don't want it to become established.”
Try to get plants out by the root, Epstein said.
“If something's really established, you can dig it out. It takes a long time,” he said. “You can also use herbicides, depending on the particular invasive species. But again, you don't want to be spraying herbicide all over the place.”
For people who do opt for herbicides, Epstein said he recommends using them carefully.
“I tend to recommend cutting it back to the ground, painting on a little bit of herbicide on some of these things, which will hopefully keep it at bay,” he said. “You can also look online. There's all sorts of other methods. You can smother it. Heat the soil up, etc.”