Roger: 0:02

Talking Trees with Lily and Jad. Welcome to Talking Trees. In this episode, we'll delve into an essential guide focused on managing viscum album European mistletoe in non-forest environments. We will outline methods for dendrological surveys and three primary strategies for mistletoe management. Additionally, we'll highlight case studies and reference materials included in this comprehensive guide. Stay tuned as we explore best practices for managing this parasitic plant in urban and rural landscapes.

Jad: 0:40

Hey, everyone, welcome back.

Lilly: 0:42

It's great to be here.

Jad: 0:43

Today we're diving deep into something I know you guys deal with all the time.

Lilly: 0:47

Mistletoe.

Jad: 0:48

Yeah, mistletoe management, yep, and we've got some interesting sources to work with A Czech methodological guide.

Lilly: 0:56

Oh, wow.

Jad: 0:57

Some safety data sheets on a specific chemical treatment.

Lilly: 1:00

Okay.

Jad: 1:00

So hopefully by the end of this deep dive you'll have some practical strategies for tackling mistletoe and protecting those trees you work so hard to care for.

Lilly: 1:08

Yeah, I mean. Mistletoe always seems so festive this time of year.

Jad: 1:11

Right.

Lilly: 1:12

But you know, when you're out in the field as an arborist, it can be a real headache.

Jad: 1:16

It's not just like a holiday decoration, it's a serious issue.

Lilly: 1:19

Yeah, and it's more than just a cosmetic problem. We're talking about a parasite that's siphoning off vital resources from the tree.

Jad: 1:26

Especially water.

Lilly: 1:27

Especially water.

Jad: 1:28

Like it's not just sharing, it's actually out-competing the tree it is. I was reading that mistletoe actually has a higher transpiration rate than most trees, so it sucks up water much faster.

Lilly: 1:38

It does. Yeah, it has a higher transpiration dynamic. Oh okay, so it's taking the water.

Jad: 1:43

So that water stress then makes the tree vulnerable to all sorts of other problems, right?

Lilly: 1:48

On so many levels, yeah, from stunted growth to increased susceptibility to other pests and diseases.

Jad: 1:56

So, before we even think about how to treat it like, how do we assess a mistletoe situation?

Lilly: 2:01

Well, the check guide. They really emphasize thorough dendrological surveys, especially, you know, during the dormant season.

Jad: 2:09

Right.

Lilly: 2:09

When you can see everything clearly.

Jad: 2:11

You don't have all that foliage in the way.

Lilly: 2:13

Yeah. But, it's not just about spotting the mistletoe. It's about assessing how bad the infestation is.

Jad: 2:18

So how do we go beyond just seeing it to like really understanding if it's a problem or not?

Lilly: 2:23

So they have this really interesting classification system in the check guide. Okay, they call it the ROFAD system.

Jad: 2:31

ROFAD.

Lilly: 2:32

Yeah, All right Stands for rare, occasional, frequent, abundant and dominant.

Jad: 2:37

Okay.

Lilly: 2:38

And so that gives you like a standardized way to assess the extent of the spread.

Jad: 2:42

Oh, that's useful. Yeah, so that tells me, like, how much mistletoe is there. But what about the tree?

Lilly: 2:47

Yeah.

Jad: 2:48

Like a healthy, vigorous tree, might be able to handle a little more than one. That's already stressed.

Lilly: 2:53

Absolutely, and that's where this guide gets really insightful.

Jad: 2:56

Okay.

Lilly: 2:56

They combine that ROFAD classification with the vitality of the tree itself.

Jad: 3:02

So you're looking at both things together.

Lilly: 3:03

Yes, and they provide this matrix that helps determine the best course of action, based on the severity of the infestation and the health of the tree.

Jad: 3:13

That's smart, so you're not overreacting to a little bit on a healthy tree Right or, conversely, underestimating the threat on one that's already struggling Exactly Okay. So we've done our assessment.

Lilly: 3:25

We know what we're dealing with, what are our options for actually tackling the mistletoe? Well, pruning, that's the most traditional method and it can be very effective if it's done right.

Jad: 3:35

So what do you mean? Done right.

Lilly: 3:36

It's not just about removing the visible clumps.

Jad: 3:40

Right.

Lilly: 3:41

You've got to prune back to that branch collar. You have to remove those embedded haustoria, those root-like structures that the mistletoe uses to penetrate the tree's branches.

Jad: 3:51

Right, you've got to get rid of the source, not just the symptoms. But pruning though it takes time, especially if you're dealing with a large tree or really bad infestation. Are there any other options that might be more efficient?

Lilly: 4:06

There are, and one that's gotten a lot of attention in recent years is chemical treatment.

Jad: 4:10

Okay.

Lilly: 4:11

Using a girth regulator called Ethafon.

Jad: 4:13

Ethafon I've heard of that. Isn't that the one that sort of tricks the mistletoe into self-destructing? Yeah, is that how it works, but that's the one Okay.

Lilly: 4:19

Specifically a product called Cerone 480SL.

Roger: 4:24

All right.

Lilly: 4:24

And it induces ethylene production within the mistletoe, which can cause defoliation and, in some cases, complete disintegration.

Jad: 4:31

Oh, wow.

Lilly: 4:32

And the best part is it doesn't harm the host tree's foliage.

Jad: 4:35

That's a big plus, especially if you're trying to help the tree recover.

Roger: 4:39

It is.

Jad: 4:40

But whenever we're talking about chemicals, you know, there's always that concern about safety and environmental impact.

Lilly: 4:45

Sure.

Jad: 4:46

What can you tell us about that with Ethafon?

Lilly: 4:48

Well, Ethafon breaks down relatively quickly in the environment.

Jad: 4:51

Okay.

Lilly: 4:52

And studies have shown it to be relatively safe for wildlife when applied correctly, that's good. Of course, as with any chemical, precise application is crucial.

Jad: 5:00

So what kind of practical advice does the Check Guide give for maximizing effectiveness and minimizing that environmental impact?

Lilly: 5:08

Well, they recommend adding a surfactant to the Ethafon solution which helps it stick to those mistletoe leaves and improves uptake. Also, timing is key. Application during dormancy, ideally just before bud break, tends to be the most effective.

Jad: 5:24

So catch it before it starts drawing resources from the tree in the spring. Exactly Okay, but this isn't something just anyone can do, right?

Lilly: 5:32

Absolutely not. You need to be properly licensed and certified to apply Ethafon for mistletoe control Right and there are specific regulations in that check guide.

Jad: 5:42

So pruning and this chemical treatment, those are our main weapons in the fight against mistletoe.

Lilly: 5:47

They are.

Jad: 5:48

But are there any situations where you know those options just aren't enough? Yeah, unfortunately, yeah, you know those options just aren't enough.

Lilly: 5:56

Yeah, unfortunately, yeah, sometimes, despite our best efforts, we have to face that difficult decision of tree removal.

Jad: 6:02

That's got to be a tough call, especially for arborists.

Lilly: 6:05

Yeah.

Jad: 6:05

You guys are dedicated to preserving trees, so when? Is it the only option?

Lilly: 6:10

When the infestation is just so severe and the tree is so compromised that it's beyond recovery.

Jad: 6:15

Okay.

Lilly: 6:16

Or if leaving it standing poses a real risk of spreading the mistletoe to healthy trees nearby.

Jad: 6:21

So it's like removing one infected plant from a garden to save the rest.

Lilly: 6:24

Exactly.

Jad: 6:25

Tough decision, but sometimes you have to do it.

Lilly: 6:27

Right.

Jad: 6:28

For the greater good of the urban forest or the landscape.

Lilly: 6:30

Right.

Jad: 6:31

And I imagine there are legal considerations too right.

Lilly: 6:33

Oh, absolutely. Yeah, you often need permits from local authorities to remove a tree, even for mistletoe management.

Jad: 6:40

Makes sense.

Lilly: 6:40

And in many cases you might be required to plant new trees to replace the ones removed.

Jad: 6:45

So you're not just taking away trees, but contributing to the long-term health of the community's trees.

Lilly: 6:50

Yeah, it's about responsible urban forestry.

Jad: 6:53

So we've covered a lot Assessing the severity, understanding the key factors for treatment and exploring those main options Pruning, chemical treatment with ethafon and, as a last resort, tree removal.

Lilly: 7:09

We have.

Jad: 7:09

And we've talked about the importance of safety, proper licensing and being environmentally responsible throughout the process.

Lilly: 7:16

Very important and you know we've talked about tackling those existing mistletoe infestations. But what about the long game?

Jad: 7:23

Right.

Lilly: 7:23

Preventing it from becoming a problem in the first place.

Jad: 7:26

Yeah, an ounce of prevention is worth a pound of cure.

Lilly: 7:28

Exactly.

Jad: 7:29

So where do we start? What are some of the most effective things we can do to prevent mistletoe from taking hold?

Lilly: 7:35

Well, one of the most fundamental things is just promoting good tree health.

Jad: 7:39

Makes sense.

Lilly: 7:39

A vigorous tree is just better equipped to resist any pest or disease.

Jad: 7:44

So give it the tools to fight back on its own.

Lilly: 7:47

Exactly Proper pruning, watering, all that good stuff.

Jad: 7:51

Okay, so it's all part of that. What about I heard? Diversity is really important when it comes to prevention too.

Lilly: 7:57

Absolutely.

Jad: 7:58

So like planting a variety of tree species.

Lilly: 8:01

Exactly, you know those monocultures.

Jad: 8:03

Yeah.

Lilly: 8:03

Where you have a single type of tree dominating an area, they're much more susceptible to these widespread infestations.

Jad: 8:11

Right, because if one tree gets hit, it can just easily spread to all its neighbors.

Lilly: 8:15

Exactly. It's like putting all your eggs in one basket.

Jad: 8:17

Right. Better to spread the risk.

Lilly: 8:19

Exactly, having a mix of species just creates a much more resilient landscape. Okay, and another key preventative measure is early detection. Okay, regular inspections.

Jad: 8:30

Especially during dormancy, when you can see better, you can catch those infestations when they're still small and manageable.

Lilly: 8:35

Exactly, you got to be proactive, vigilant.

Jad: 8:39

Even with all those preventative measures, sometimes mistletoe still gets through. What's our next line of defense?

Lilly: 8:46

Well, then we go back to those treatment options.

Jad: 8:48

Right.

Lilly: 8:49

Pruning, chemical treatment or, in those really tough cases, tree removal.

Jad: 8:53

Like a battle plan with different levels of engagement.

Lilly: 8:55

That's a good way to put it and the right strategy. It really depends on the specific situation.

Jad: 9:00

Makes sense.

Lilly: 9:01

You know the species of the tree, how bad the infestation is, the overall health of the tree the environment, the surrounding environment, absolutely.

Jad: 9:10

You've got to be able to assess, understand and make the right call.

Lilly: 9:14

Exactly, and no matter what treatment method you choose, you've got to monitor. Mistletoe is persistent, it can come back.

Jad: 9:22

So follow-up inspections are key.

Lilly: 9:24

Absolutely, and you know, technology can be a real asset here.

Jad: 9:27

Okay, how so?

Lilly: 9:28

Remember that online platform we mentioned earlier.

Jad: 9:31

Yes, I do. The check guide talked about it for tracking treatments and monitoring progress.

Lilly: 9:42

It's a great tool to document your mistletoe management efforts. You can input all kinds of data the tree species, location, the type of treatment, the date. You can even upload pictures to document the infestation before and after.

Jad: 9:52

So you're creating like a detailed medical history for each tree.

Lilly: 9:56

Exactly and having that information accessible really helps you see trends, see what's been effective and make better decisions about future treatments.

Jad: 10:04

It's like having a command center for all your mistletoe operations.

Lilly: 10:07

It really is. You know, speaking of the bigger picture, mistletoe is more than just a pest. It has a really interesting and complex relationship with the ecosystem.

Jad: 10:16

We've been talking a lot about the negative impacts. Are there any potential benefits, Like does mistletoe actually play an ecological role?

Lilly: 10:26

It does Well. For one thing, those dense clumps of mistletoe they provide shelter and nesting sites for birds and small mammals. And those berries while they're toxic to us, they're a food source for certain bird species.

Jad: 10:42

So it's supporting biodiversity in some ways.

Lilly: 10:44

It is. It's a good reminder that these ecosystems are full of these complex relationships.

Jad: 10:49

Right.

Lilly: 10:50

And even a species that we might consider harmful can have benefits for other parts of the web.

Jad: 10:56

It makes you think about the balance, right it does.

Lilly: 10:58

How much is too much? How do we manage for the health of the balance? Right, it does Like. How much is too much, yeah. How do we manage for the health of the trees, but also the overall biodiversity of the ecosystem?

Jad: 11:08

Those are really important questions and they lead us to something that's going to play a big role in mistletoe management going forward.

Lilly: 11:15

What's that?

Jad: 11:16

Climate change.

Lilly: 11:16

Right, because climate change is already impacting forests in so many ways. How's it going to affect the mistletoe situation?

Jad: 11:24

Well, some research suggests that warmer temperatures and changes in precipitation could actually create more favorable conditions for mistletoe growth and reproduction.

Lilly: 11:36

So we might see even more mistletoe in the future.

Jad: 11:38

It's definitely a possibility.

Lilly: 11:39

Especially as things get warmer, maybe even drier.

Jad: 11:42

Potentially Well. This has been a really interesting look at mistletoe management.

Lilly: 11:47

It has.

Jad: 11:48

From the tiniest little detail of those haustoria to these big picture issues of climate change and how forests are changing.

Lilly: 11:55

The whole spectrum.

Jad: 11:56

We covered a lot of ground today.

Lilly: 11:58

We did.

Jad: 11:59

Assessment, treatment, prevention, even those surprising ecological roles that mistletoe plays.

Lilly: 12:05

We get it all.

Jad: 12:06

And I hope we've given everyone some good tools and techniques to take back with them and apply in the field.

Lilly: 12:10

I hope so too.

Jad: 12:11

Thanks to everyone for listening to this deep dive on mistletoe management. We'll see you next time.

Lilly: 12:17

See you next time.

Roger: 12:25

Thank you for joining us on this episode of Talking Trees. Today, we explored practical strategies for managing mistletoe in non-forest environments, emphasizing tailored interventions based on tree health and infestation severity. Stay safe, keep learning and we'll see you next time on Talking Trees.