combating weeds: an all-season strategy, with mt. cuba’s duncan himmelman

Jenna Harris November 1, 2020 9 No Comments

fighting weeds: an all-season approach, with mt. cuba’s duncan himmelman

‘THERE’S ALWAYS a weed on the market, irrespective of when.” That’s what at the moment’s visitor, training supervisor Duncan Himmelman of Mt. Cuba native plant heart in Delaware, stated the opposite day on the telephone. And which means now, whilst we strategy the quiet season, weeds are lurking, and we have to know when and the best way to goal our efforts to regulate them.

Duncan Himmelman, at present the training supervisor at Mt. Cuba Center, a renown native plant backyard and analysis web site, earned his doctorate in decorative horticulture at Cornell earlier than educating school for 24 years. He’s additionally managed a big non-public property and designed gardens for personal purchasers, so he is aware of from weeds and weeding.

We talked about weed ID, and why it issues to know a weed’s identify and life cycle (that’s chickweed, Stellaria media, a winter annual, above; photograph from Wikimedia). We additionally mentioned removing ways and why skipping the chemical compounds makes the most effective sense, and extra.

Read alongside as you hearken to the November 2, 2020 version of my public-radio flash and podcast utilizing the participant under. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify or Stitcher (and browse my archive of podcasts here).

mt. cuba’s 6 new digital lessons on demand

A COURSE on weeds is one in all a half-dozen on-demand recorded programs Mt. Cuba is at present providing to the general public (extra on that under, within the transcript–or browse them now). Enter to win a ticket (on me!) to the course of your alternative by commenting within the field on the very backside of this web page.


fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelmanall-season weed management, with duncan himmelman



Margaret: Seen any weeds but this morning, Duncan? [Laughter.]

Duncan: Well, no, I’m averting my eyes. No, they’re in all places as you recognize.

Margaret: So we should always say to everyone that what received me alerted to your weed course—effectively, what received me alerted to the truth that you had been into weeds and educating a course on weeds truly, which is one in all the recorded courses at Mt. Cuba that folks should purchase on demand—was that I received a press launch about this entire sequence of digital lessons.

The lessons are an awesome useful resource; you guys have nice in-person occasions when the world permits and so forth as effectively. But I puzzled if you happen to may simply inform us about this providing of digital lessons on demand.

Duncan: Yeah. As you recognize, when COVID struck, we hadn’t carried out any on-line training. And so we needed to shortly pivot to transition our lessons that had been going to be reside and in-person to on-line. And because of that, we report every class and the recordings have been filed and a few of them have been stored for resale, as you talked about, as recordings in our classes-on-demand possibility. And there are six of them: One is on soils. One is on the most effective native crops for containers. There’s one on monarch butterflies, a butterfly backyard, and groundcovers, and weeds.

Margaret: Yes, it was nice since you guys, I imply, I at all times love speaking to anybody on the workers there and I learn so much, so I used to be so excited to see and to have the ability to share.

So as I began at getting all the way down to enterprise, as a result of we received to do some weeding, Duncan. As I stated at first quoting you, “There’s always a weed out there, no matter when.” So what’s a weed? Let’s simply shortly begin there earlier than we get to ways.

Duncan: Yeah. Generally it’s outlined as one thing that’s rising in a spot the place it’s not needed; that technically it’s misplaced. In that sense, it could possibly be something from widespread dandelions, as all of us effectively know, as much as even a tiny shrub that’s planted within the flawed location in your property. Not that folks would think about {that a} weed within the sense that we sometimes do, however yeah, it’s basically a plant that’s rising the place it actually isn’t needed.

Margaret: Right. And the issue with these is that they compete towards the needed crops, proper?

Duncan: Yeah. I imply, all crops are taking on water and vitamins within the soil, and they are often limiting. So weeds are taking those self same water and vitamins for themselves, on the expense of the crops that you simply actually need in your backyard. So yeah, competing for assets is among the ways in which weeds are profitable.

Clearweedm or Pilea pumilaMargaret: So simply to be clear, I imply, Mt. Cuba is that this well-known and fantastic native plant heart—a spot of training, a spot of analysis, and so forth. Not all weeds are aliens, i.e., non-native. There are “native weeds,” quote unquote, and there are generally native crops which are within the flawed place; they’re a tiny too bold.

So it’s not “that’s an alien and that makes it a weed,” proper? I imply, now we have clearweed, Pilea pumila [above], I believe it’s referred to as, jewelweed, and pokeweed. They even have weed of their widespread names, some conventional native crops which have nice wildlife worth, too, however perhaps the gardener sees them as a weed in sure spots.

Duncan: Yeah. The manner our gardeners handle the panorama is to edit out crops which are going to be, as you stated, too rambunctious or too aggressive. So we do have pokeweed on the property and it may be very… it will probably seed in pretty prolifically and it’s a perennial and it’s troublesome to eliminate. But they do depart the odd one right here and there as a result of it’s native and so they do present ecological companies which are fairly vital. So yeah, not all weeds within the sense that you’d outline them are alien.

Margaret: Yeah. I don’t know if you’re a field-guide nerd like I am, however I’m. I’ve an entire cupboard filled with area guides, and a lot of them are about weeds. And I really like understanding the names of my weeds. I really like with the ability to ID my weeds. In the category on weeds, do you encourage folks to get to know them by their correct names?

Duncan: Yes. I imply, I come from an extended line of a few years of educating, and it’s at all times finest to show the scientific identify of the plant as a result of that’s the bonafide identify that follows that plant oh, from nation to nation, from state to state, and so forth. So yeah, I’m at all times very liable to utilizing the scientific identify once I speak about weeds and different crops on the whole. So I’ll generally stumble over the widespread names as a result of I’m not as used to utilizing them.

But we give each of them to our college students and we emphasize the truth that if they’ll truly be taught the scientific identify of those crops then they’ll do their analysis on-line in a simpler method.

Margaret: And I’m going to provide some hyperlinks, a few of which you shared with me and a few that I take advantage of myself, to some online weed ID resources from varied universities across the nation and so forth that folks could discover helpful for studying some fundamental ID, and in addition to some information books and so forth [links at bottom of page].

So that will get me considering, talking of the right identify of chickweed, Stellaria media is how I say it [photo top of page]; I don’t know if that’s proper. But I used to be exterior this week in my backyard and on the edge of 1 big mattress, there have been numerous tiny chickweed crops. Now, what the heck is it doing as winter approaches, seeming to begin to develop? [Laughter.]

Duncan: Yeah, I do know you’re considering of that weed season is over.

Margaret: What’s happening?

Duncan: It’s heading into winter and we don’t have to fret about weeds anymore, however as you recognize, weeds don’t take any day without work. With Stellaria, chickweed, what you’re seeing is tiny rosettes or tiny seedlings arising presently of yr. And the rationale they’re arising is as a result of it’s cool and moist, and these are the perfect sorts of germinating circumstances for what we name winter annuals.

And it type of will get again to your earlier remark about why are they arising presently of yr; we’re heading into winter. So they’ll germinate now. And there’s a lot of these winter annuals that may flash their heads at this second and they’re going to stay inexperienced on this vegetative state all through this a part of the season, go dormant, after which in early, early spring, when winter is simply subsiding, they’ll begin to flower. So these winter annuals, love chickweed, will bloom early within the spring. And I believe folks have seen that, that, wow, right here’s this plant, it’s very early, it’s love April, what’s happening, it’s already flowering? But it’s been sitting there, dormant, within the leafy stage over the winter. So yeah, that’s what’s happening. There’s an entire bunch of these items referred to as winter annuals.

Margaret: Yeah. So it appears to me that it’s going to be rather a lot simpler to reckon with these tiny guys than who they’re going to change into by April or later, sure? So, I imply, this provides us some tactical hints, understanding the life cycle, understanding that it’s a winter annual, proper?

Duncan: Yeah.

Margaret: So is {that a} technique then that I ought to be coping with this now, not ready till it will get worse? I imply, that appears apparent, however in some instances it’s not fairly as apparent.

Duncan: Yeah. Since it’s an annual, many of the annual weeds that folks will encounter ought to be eradicated, eliminated, once they first see them arising as seedlings or barely legal crops. And it’s no completely different proper now with the winter annuals. You see them arising and if you happen to acknowledge them as chickweed, for instance, then you must actually eliminate them now, earlier than they go into the flowering section.

Some of the sorts of weed-control strategies that we at all times encourage right here at Mt. Cuba Center is to go in and simply grub them out, utilizing bodily labor, and get them early on. They’re annuals; if you happen to pull them out of the bottom and expose the roots, they’ll dry up and die. So yeah, your intestine feeling is, “O.K., yeah, I see these little plants. It’s time to get out there and start weeding them out.” So you’ll be able to hoe them out or no matter you want to do.

Oriental bittersweet seedling in a sea of ground ivy or GlechomaMargaret: At the sting of one other mattress, my nemesis is one in all my many nemeses… And it’s probably not a horrible weed nevertheless it’s irritating as a result of it likes to crawl in from the perimeters of the garden, into beds, into decorative beds. And it’s Glechoma hederacea, what do they name it, creeping Charlie or one thing, floor ivy, is that what they name it? That’s one other one which proper now it’s love it has superior once more. It appears to have loved some latest rains and who is aware of what this fall. [Above, ground ivy in the foreground with an Oriental bittersweet seedling and even one of garlic mustard in the middle.]

Duncan: Yeah. Glechoma hederacea is floor ivy. They can name it creeping Charlie. They can name it gill on the bottom or gill over the bottom as effectively. And it’s a perennial, yeah, it’s truly a perennial weed that you must actually attempt to eradicate each time you truly see it, attempt to pull it out and take away it.

It has a reasonably dense root system. And it’s the type of plant that if you happen to can take away it bodily manually, the extra you’ll be able to take away it, the extra profitable you’ll be at stopping it from spreading, as a result of it does unfold over the bottom, therefore its widespread identify, and it’ll persist. So yeah, it has taken a tiny little bit of day without work. It’s gone a tiny bit dormant within the dry a part of the season, and now it’s coming again. So I’d undoubtedly suggest you attempt to eliminate that as a perennial, and attempt to get the foundation system out. That’s the issue with perennials in fact, is that their root programs maintain onto loads of saved meals and preserve these crops going.

Margaret: Yeah. And that is one the place it appears to the touch down in a number of locations, it’s love lengthy tiny runners and so they appear to have rooted in, in a number of locations, virtually vine-like above the bottom.

Duncan: Yeah.

Margaret: It’s nice when the soil is moist, it’s very satisfying for a loopy particular person love me to type of pull it out gently, slowly, so that you simply get alongside the entire lengthy extent of it, so to talk. Yeah. So that’s one other one I’m going to be tackling, although once more, now we have snow forecast late this week, however so what, I’m going to try this; I’m going to do one other go on that one. And you say that’s a perennial, in order that is smart. And then there’s garlic mustard. [Laughter.]

fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelmanDuncan: Oh God. Yeah. Garlic mustard [Alliaria petiolata, above]. Oh sure. Well, the excellent news is you’ll be able to flip it into pesto sooner or later, however you don’t need to have that a lot garlic mustard in your property, do you?

Margaret: No. And isn’t {that a} biennial? We simply talked about a winter annual. We talked about a perennial. Is {that a} biennial? I believe, is it?

Duncan: Yeah, it’s. It’s a biennial. And what you’re most likely seeing now’s what they name rosettes or tiny clumps of the plant that are actually arising. They’ve germinated and so they’re rising and so they’re most likely three to four inches tall and so they’re only a sequence of leaves. And they’ve that attribute type of pungent odor to the foliage if you happen to crush it.

But yeah, you may get on the market and eliminate the plant proper now as a result of it’s going to go, once more, it’s going to go to flower and seed very early within the season, come spring. So the extra you’ll be able to eliminate garlic mustard… It’s a biennial, so at this level while you pull it out, it’ll appear love an annual as a result of the foundation system is simply from this yr. So pulling it out now might be well-advised as a result of A, you’re most likely not going to get all of them. You’re going to 90% of them and also you might be able to catch the remaining few within the spring. But yeah, get them out now as a result of man, they’re up and flowering and seeding fairly early.

Margaret: And this one has loads of weedy tactics. It’s profitable as a result of it’s a prolific self-sower, as a result of it’s allelopathic, I believe; I believe it exudes a chemical within the surrounding soil space that stops different crops from getting acclimated, getting began. It’s a difficult one. So actually to get it out, as quickly as you see it can be crucial, I believe, earlier than it does these issues.

Duncan: Yeah. And not solely that, nevertheless it’s very tolerant of shade and solar. And so that you’re going to see it far and wide. You’ll suppose, oh, effectively it’s shady over there, it received’t invade. But no, it does. It takes the shade. The factor about it’s that, in fact it’s germinating and rising foliage this time of yr, after which within the spring, when there aren’t loads of leaves on the bushes above, they’ll proceed to develop after which shortly go to flower. So, it’s a fairly good weed.

Margaret: It could be very, nevertheless it’s not smartweed, which is the widespread identify of one thing else altogether. [Laughter.]

Duncan: I do know. I do know. All proper. Yes. Smartweed. Although many weeds are good, there’s smartweed. Is that Polygonum, I believe? Anyway.

Margaret: Yeah.

Duncan: Yeah. I do know. And there’s many polygonums as effectively, so good god. [Laughter.]

Margaret: Yes. So we’ve simply talked a tiny bit about understanding not solely … understanding its correct Latin identify, ID’ing it, utilizing a few of the instruments, we’ll give some hyperlinks to, or having the proper e book on your area, a area information for area. ID’ing it, attending to comprehend it by its correct identify, doing a tiny homework. Is it an annual? Is it a winter annual? Is it a biennial? Is it a perennial? That can get you a few of the technique brewing on the best way to take care of it.

So let’s speak about management measures as soon as we all know that. So you had been saying Margaret ought to get on the market and grub out these chickweed seedlings and he or she ought to be pulling, fastidiously pulling, a few of the perennials. And biennials love those we’ve simply talked about, the Glechoma and the garlic mustard. So what are a few of the different ways of weed removing that you simply educate?

Duncan: Yeah. Well usually once we speak about we management, Mt. Cuba Center tends to not depend on loads of chemical measures. And so at school, we suggest that folks actually attempt to exclude weeds from stepping into their yard to start with. And one of many ways in which they’ll do that’s that once they go to the backyard facilities or nurseries, they’ll take a look at the pots and containers that the crops are in, and if any of them have weeds in them, then they shouldn’t select these crops. And they need to be working with nurseries which are pretty diligent about conserving weeds out of their containers.

So we attempt to exclude weeds, however as you recognize, weeds… Dandelion seeds are blowing in, weeds are, simply coming in, on the whole from surrounding properties.

Another technique that we suggest is to maintain your instruments as clear as attainable. I do know it sounds mundane, however love you, I’m on the market, I’m weeding, I’m utilizing my gardening instruments. And then I believe, “Oh, well I’ll just put them down and pick up where I left off tomorrow.” But the extra you retain them clear, the higher you’re going to have the ability to preserve weeds from coming into your … from spreading weeds round per se. Does that make sense?

Margaret: So from seed that’s on it or a tiny bits of plant or seeds within the soil that’s left in it?

fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelmanDuncan: It might be each. If you’re digging up some mugwort [Artemisia vulgaris], for instance, and pulling it out and amassing mugwort [above], then the shovel you utilize could have tiny items of mugwort roots on it and also you’re simply transferring the spade to a different a part of your backyard. And you’re going to make a brand new mattress, and abruptly a yr or two later, you see mugwort cropping up within the new mattress. When you suppose, the place did that come from? So yeah, it may be seeds and it may be tiny items of crops as effectively.

Margaret: Right. Which can also be true while you need to transplant a fascinating plant from one mattress to a different mattress. If that mattress, the primary mattress, has some infestation of one thing you’re operating the chance of… if you happen to don’t wash off that division that you simply’re making of that. It is perhaps a hosta, for goodness sake, which isn’t a weed, however if you happen to don’t wash it off, if there’s an adjoining weed in that mattress, you might be bringing it alongside to the brand new mattress the place you place that division, yeah?

Duncan: Yeah. It’s so fascinating you talked about that, as a result of I’ve carried out precisely that the place I’m digging up a plant and I do know that plant X, the weed is in amongst these roots as a result of the weed tends to unfold round. And I’d actually, I’ll sit there and I’ll discern what’s the weed and what’s the root of the specified plant?

Margaret: [Laughter.]

Duncan: And I’ll tease all of it aside. Even if I lose all of the soil across the plant I’m transplanting—a herbaceous perennial, for instance—I’ll attempt to be as meticulous as attainable at getting all of that tiny weed root out of there. And so it kind of means you must know what the weed root seems love and the foundation of the fascinating plant. So it’s not simply the leaves and the flowers of the weed, you must know one thing about their roots. But yeah, you must be very diligent. Good level.

Margaret: Yeah. So these are some preventive issues. Grubbing out is one removing space. What about can I exhaust a few of these crops, love with repeated a few of the ones which are extra tenacious? If I can’t get them out fully, what are another ways?

Duncan: Yeah. I imply stopping our weeds from going to seed as we talked about earlier, getting the tiny seedlings out proper off the bat. But with perennial weeds, and you’ll consider issues love plantain [below] or dandelions or what else can I consider?

fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelmanMargaret: Thistles. Those rattling thistles. All these thistles.

Duncan: Thistles, yeah, I do know. And thistles have roots from right here to eternity, however we’ll attempt to put that on maintain for the second. With issues love perennial weeds of that nature, then you definately actually simply should get at getting the foliage out as usually as attainable. Remove the foliage as usually as attainable. Mow it down, pull off the leaves, attempt to dig it out and take away it.

The extra you’ll be able to take away the foliage, the weaker the plant will change into, which means that the leaves are the supply or the positioning of photosynthesis. And that’s the supply of the plant’s meals. And with out plant meals, then the roots will not be going to proceed to develop.

So if you happen to take away the leaves, take away the supply of meals for the plant itself, then you’ll in the end weaken it. And you must be very diligent about this, as a result of these leaves are going to return popping again, as you effectively know. But if you happen to actually do preserve at it inside three or so years, you’ll be able to most likely actually, actually preserve that weed down.

Margaret: Right. So no photosynthesis is finally no plant, proper?

Duncan: Yeah. Exactly.

Margaret: So stopping photosynthesis. Yeah.

Duncan: Right, proper, proper. And talking of that as effectively, we do speak about mulching and mulching is-

Margaret: I used to be going to say, do you mulch?

Duncan: We do mulch right here with leaf mulch. And in one in all our gardens, we’re mixing up a few of our home made woody plant-sourced mulch with the leaf mulch. So it’s type of a half-and-half. It’s a really finely shredded woody materials, and the leaves which have been shredded as effectively. So it’s not love a rough mulch love you’d see on the backyard facilities on the market.

So type of is a transition space kind of between a compost, type of factor.

But yeah, we do mulch, and I believe the vital factor about mulching your backyard is to make use of one thing that’s natural clearly, and to layer it as much as 2 to three inches. I bear in mind years in the past there was analysis carried out on what’s the depth of mulch that you must use. And usually they got here up with three inches of depth as a result of that may forestall weed seeds from germinating, and so forth. Some folks say 2 inches. I’m extra inclined to say three inches as a result of then, you’ll be able to depart it there alone. As it decomposes, you must clearly, renew it. So if I layer on round three inches of mulch round my backyard crops, then I don’t should continuously reapply mulch. You know what I imply?fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelman

Margaret: Right, proper. I simply need to shortly simply shout out that I get a tiny nervous, and I shared this with you on the telephone the opposite day, I see the massive bottles of acetic acid, so-called horticultural vinegar, within the shops—within the backyard facilities—and I shudder considering of everyone spraying them with out the proper correct safety. Do you ever use these, the acetic acid, the horticultural vinegar in any respect? And what’s it for, if it’s going to be used?

Duncan: We aren’t utilizing the horticultural vinegar, no.

We have had some extent of success utilizing another merchandise right here on the backyard. Organic chemical compounds principally work in the identical sense as you’d apply to eradicating the highest foliage. So in a perennial scenario, you need to take away the leaves. Even with an annual, if you happen to take away the leaves, you’re going to essentially take away the plant.

So a few of the merchandise that we’re utilizing listed here are principally made out of pelargonic acid blended with fatty acids, or citric acid and clove oil. Another product that we’ve used is one which has lively chelated iron. And they principally act as foliage burns. They burn the foliage. And in that sense, they’re most likely handiest on barely legal crops. So now we have used some right here on the grounds. I can distinctly scent the clove oil once in a while. But these merchandise will not be selective.

And while you stated you cringed earlier with horticultural vinegar, even with these merchandise, you’ve received to be very, very particular in concentrating on the plant you need, as a result of something inexperienced that they’re sprayed on can be broken.

So I believe that the most effective strategy could also be to attempt to do handbook removing. Try to plant your backyard beds as densely as attainable with the crops you need. I imply, weeds are very good.

Margaret: Right; to outcompete weeds, proper.

Duncan: They get into areas which are open and out there. So we do suggest that you simply make your backyard beds pretty dense with the crops that you really want. We use native crops clearly. And we attempt to not use the natural compounds, however as I stated, they’re very efficient on barely legal crops, however they’re not selective.

Margaret: Right. And at all times learn the label and use the safety—eye gear, and so forth., that it says to make use of on the label.

Duncan: Absolutely. Yes, completely. And don’t suppose twice as a lot is best as a result of the-

Margaret: No, no, no, no, no, no, no.

Duncan: Because the businesses which have developed these know that that is the focus you need to use.

Margaret: Well, Duncan, I hope you’ll come again and speak about one in all your different lessons, the native groundcovers, as a result of I do know that may be an enormous hit. And love I stated, I’ll give hyperlinks to all of the weed resources [more links below] and the classes that you’re offering on demand now from Mt. Cuba. And I thanks a lot for making time at the moment.

Duncan: Yeah. Well thanks, Margaret. It’s been a pleasure speaking weeds with you and yeah, groundcovers is one other massive favourite of mine.

Margaret: Good.

Duncan: And so I sit up for listening to from you once more, and need everyone the most effective of their winter weed management.

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fighting weeds an all season approach with mt. cubas duncan himmelman - combating weeds: an all-season strategy, with mt. cuba’s duncan himmelman

I’LL BUY on-demand classes of their alternative for 2 fortunate readers, from amongst Mt. Cuba’s six present choices: summer time weeds, natives for containers, milkweed and monarchs, butterfly gardens, native groundcovers, and one on soil. All you must do to enter is reply this query within the feedback field on the very backside of the web page:

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MY WEEKLY public-radio flash, rated a “top-5 garden podcast” by “The Guardian” newspaper within the UK, started its 11th yr in March 2020. In 2016, the flash received three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station within the nation. Listen regionally within the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the November 2, 2020 flash utilizing the participant close to the highest of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify or Stitcher (and browse my archive of podcasts here).

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