Talking Trees with Davey Tree
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Talking Trees with Davey Tree
Helping Pollinators Thrive: Native Species, Plant Picks and More
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Adam Baker, research entomologist at the Davey Institute, tells us how we can support pollinators, including planting native species, choosing pollinator-friendly plants and why it all matters.
To find your local Davey office, check out our find a local office page to search by zip code.
To learn more about helping pollinators, please read our blogs Creating a Pollinator Garden (Pollinator Plant List), Tree Pests vs Beneficial Insects, Do Bees Like Trees? Trees for Bees Guide and Ultimate Guide for Best Flowering Shrubs.
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Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!
Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host, Doug Oester. Each week, our expert arborists share advice on seasonal tree care, how to make your trees thrive, arborists' favorite trees, and much, much more. Tune in every Thursday to learn more because here at the Talking Trees Podcast, we know trees are the answer. I'm joined today by Adam Baker. He's a research entomologist with the Davy Institute, uh part of the Davy Tree Expert Company in Kent, Ohio. Today we're talking all about trees that support pollinators. This is exciting to me, uh, Adam. Welcome back to the show.
SPEAKER_00Thanks, Doug. It's always uh great to chat with you, and especially if we're talking about pollinators. So thanks for having me on.
SPEAKER_01Well, you know, pollinators in general, as like from the gardening standpoint, everybody's trying to help pollinators. They're planting milkweed, they're planting all sorts of other things. When it comes to trees, what should we be thinking about with pollinators?
SPEAKER_00Well, uh, you got to think about for pollinators,
Supporting adult and larval pollinators
SPEAKER_00we're talking about the things that are transferring nectar and increasing uh plant reproduction by um creating genetic outcrossing between unrelated species. So oftentimes there's a misconception that we talk about trees for pollinators, we talk about supporting their larva as well. So you gotta you gotta think about your goals in mind. You want to support the larval forms of these insects, aka caterpillars, or you're more interested in supporting the adults, which would be the butterflies, moths, bees, and wasps, things that are actually interacting with the flowers. So choosing flowers are gonna be highly attractive to those species. Uh and they're gonna be blooming at different times during the year. Uh, there's things like that that you can kind of hit to hitch sort of your goals for your own property.
SPEAKER_01So we might want both of those things, right? We want to help the adults and the larva.
SPEAKER_00I'm thinking a perfect scenario, we want to support both larval forms and adult forms of pollinators, and we can do that with uh, you know, with our our plant selection on our properties, uh having things like oaks that are going to support a wide variety of the larval forms of moths, especially. Then having things that you know bloom early, like red buds that can support early season uh ground nesting bees, or having things that bloom really late in the season. Um, even non-natives like something like Seven Suns flower, which is a highly attractive uh tree that blooms in September, which can support monarch migration and all those late season bees.
SPEAKER_01You just mentioned one of my favorite kind of under-the-radar
Prioritizing native plants
SPEAKER_01plants, the hepticodium. Uh I love that kind of tree-shrub thing. It'll grow anywhere. And like you said, it's got the late blooms, uh, but it's a it's a beautiful tree, uh tree-shrub, whatever, I guess tree, uh, with the exfoliating bark in the winter and uh those late white flowers that fade to red. It's it's a plant that's becoming a little bit more popular, but like I said, it's kind of off most people's radar, right?
SPEAKER_00Yeah, for sure. I mean, I think we always kind of want to stick to uh leaning towards more native plants on our properties to support those larval forms of pollinators, so maybe a 70-30 split of native, non-native. But one way to really utilize non-native, non-invasive species is to identify areas where we don't have bloom coverage that native plants offer. And hepicodium is a perfect example of a tree that can fill in those gaps for seasonality and support those late season bumblebees and those migrating monarchs.
SPEAKER_01Is there a season where most
Blooming season
SPEAKER_01trees are blooming, or does it just it certainly depends on the species, but for the most part, does it go through the whole season, like we go from a red bud all the way to Hepticodia?
SPEAKER_00Uh, there do seem to be some gaps, um, especially during the heat of summer. Not a whole lot of things are flowering then. We may want to think about our perennial flowers during those times to fill in those gaps. But uh, you know, oftentimes the native trees are generally blooming up until maybe at the end of June. And um, but the later season stuff is a little harder to come by.
SPEAKER_01Well, I know people hate the Rosa Sharon,
Rose of Sharon
SPEAKER_01but I love Rosa Sharon. Uh and so there's a there's a summer bloomer that would be decent for pollinators.
SPEAKER_00Um, in my experience, it's not super attractive. Um, we did a lot of surveys when I was uh undergrad in University of Kentucky with Dan Potters and Bernie Mox. Um trees, the trees and shrubs. This is Port Bees publication. Um so we looked at, I think what 75 woody species during that stuff during that study and did collections of bees off of them to and also observations to mark uh visitation rates as well as uh community diversity. Um Rosa Sharon is one that can be very aggressive. So um, if you're not the the avid gardener that's out there controlling it or having strategies to stop it, it's not one that I would necessarily recommend. Whereas something like Seven Suns flower doesn't seem to have any sort of invasive nature and is not going to easily escape uh from your planting.
SPEAKER_01So
Sterile varieties
SPEAKER_01some of these plants, like rose of sharon, they're coming out with sterile varieties. Does that affect pollination pollinators?
SPEAKER_00Uh certainly. Um often uh heavily genetically modified uh and bred for uh variations or selections of plants uh that that create sterile bracts are not going to be offering rewards for pollinators. Um, so things like the highly modified hydrangeas uh often don't have rewards for pollinators. Things like the highly modified hybrid sea roses, which have tons and tons of petals, make it difficult for pollinators to actually access that compared to like an old-world rose that has an open uh plate-like uh flower that's accessible to almost any type of pollinator that's interested in uh utilizing that that nectar pollen.
SPEAKER_01Yeah, so oftentimes when they do breed into a double flower, it's not for the pollinator, it's for the gardener, right?
SPEAKER_00Exactly. And we don't want to demonize that too. I think there's a place for cool selections with interesting colors and and variegated varieties and things like that. But just you know, keep in mind, you know, just skew towards having more natives and more wild types, and then have those few selections for your enjoyment and to create interest and and you know, start discussions in your own garden.
SPEAKER_01It does
Diversity between native and selected species
SPEAKER_01feel good to be growing the natives, the service berries and stuff like that, because you feel you're helping. Are we helping?
SPEAKER_00Um, certainly. You know, um I like you if you drive around and you and you see neighborhoods that are not invested in in plant life, we I like to refer to those as blandscapes, right? When you have one or two species and you can imagine what they're supporting, which is probably next to nothing. Um, so I think uh every homeowner has uh the chance to take part in conservation by turning their uh their property into a little oasis for pollinators and diversity. And you know, um, there's been a bad stigma on insects. You know, if you look at back at the the early movies, the big, you know, the the killer queen wasp and all these movies that portrayed insects as these scary and dangerous things. The reality is there's very few insect species that are a danger to us, and that that diversity can often lead to uh better health for us, uh reduced stress, uh, and things like that in your own in your own uh backyard.
SPEAKER_01Well, as an insect expert, you you have to be
Insect controversy
SPEAKER_01upset in the way that I am, in the way that insects are demonized. Uh I spend a lot of my time talking to gardeners and telling them you don't need to get rid of an insect just because it's there. Uh and I I think Madison Avenue has has demonized insects. Uh and as an entomologist, I would assume that's pretty frustrating.
SPEAKER_00Uh yeah, certainly. Um, you know, insects are one of the most interesting um evolutionary uh things on the planet. They just fill so many interesting niches, they have so many of these unique modifications that lead to them uh being able to survive in the wild. Uh, one of the perfect examples of an insect that often gets a bad rap are you know bees. You know, oftentimes bees are blamed for the crimes of wasps and specifically mostly yellow jackets, right? So yellow jackets uh uh can be aggressive, they can come and try to steal or take a sip of your Coca-Cola when you're at your picnic. They can lead to stings because oftentimes they get caught in clothes or hair. They're not actually trying to go out there and sting you and be aggressive unless you're messing with their nesting site. Um, but oftentimes bees get blamed for that, where it's it's pretty difficult to get stung by a bee unless you're you're really trying or grabbing them or you're messing with their nesting site.
SPEAKER_01I mean, I have two honey bee hives in a 30 by 40 garden space, and I there is no concern whatsoever. You they're doing their job and they're not interested in me in any way. And I'll tell you what, when they're doing their job, it's making my job as a gardener much easier, especially when it comes to vine crops. Boy, I'll tell you what, you you put a hive of bees in the corner and uh your zucchini, you're gonna have uh zucchini like the old days, where if somebody stopped too long in front of your house, you threw a bag of zucchini in the back seat.
SPEAKER_00Yeah, that's right. I mean, it's always good to proceed with caution with uh apiaries. Um, you know, different hives have different mentalities and different levels of aggression, but oftentimes, in my experience, uh they're way more interested in collecting pollen and and and doing their thing. And uh oftentimes you could be near the hives and and they'll they'll fly right around you and they're like I said more interested in the flowers than they are you.
SPEAKER_01You know, you don't want to bang into it, you don't want to block the entrance, but uh, I'm working in there all the time, and uh it's never been an issue. But you're right about the the attitude sometimes of a of a hive, especially if it goes queenless, they get mad, and you know you know something's wrong. Uh someone posted a picture
Linden tree
SPEAKER_01recently uh on social where I saw uh or was a video of a linden tree, and they said if you look close, you'll see the bees and pollinators are all over this linden.
SPEAKER_00Yeah, linden tree is is one of the trees that we looked at uh during the pollinator study. Um, and that was one of the most attractive trees that we found in general. Um, as you can see in almost all the pesticide labels now, there's uh linden is specifically called out uh as a tree that cannot be treated by various pesticides because of just its sheer attraction to bees.
SPEAKER_01I've told this story before, Adam, but there was a friend of mine that was a gardener at an amusement park here in Pittsburgh, and there was a whole stand of lindens, and she said it was so fragrant that it was it was overkill, that it was hard to work in that space when those things were doing their thing when they were really blooming. Uh that's an interesting tree, huh?
SPEAKER_00Yeah, it's an interesting tree. It's got a nice form, uh, highly attractive. Um, you know, if you're really, really concerned about aesthetic value, um, maybe a linden's not great for you because there's also another bug that likes linden trees a lot, and that's the Japanese beetles. So they'll often uh skeletonize the leaves and gives it that bronzing effect. And like I said, we we mostly cannot treat for anything like that because of the pollinator attractiveness.
SPEAKER_01In uh your work and and these studies that
Trees and shrubs that attract pollinators
SPEAKER_01you've uh participated in, what are some of the other trees that that are uh highly attractive to pollinators that we should be planting?
SPEAKER_00Um well, I'm gonna mix in trees and shrubs because um uh it just makes sense to me that way. But some of them some of my favorites are uh if you're looking for a interesting architectural uh smaller form sort of shrub, um, which will be anywhere from you know six to fifteen feet tall, is a bottle brush buckeye. Um it's got a great tall 10, 12-inch long panicle flower, um, attracts a lot of really cool pollinators, especially things like tiger swallow tails and some of the larger bees. Um some of the other ones I really like are, of course, red buds. Red buds, you know, come out early, they flower before they even leaf out. So we're supporting those early season bees that that pop up and in in spring and sort of dissipate by about June or so. Um some of the other flowers that I really like are um I like uh some of the the taller buckeyes as well. They're they tend to be pretty good for uh for bumblebees. Um although uh this one can be a little bit problematic. The uh sumacs are often highly be attractive, another shrub that you'd have to you know either contain or embrace uh the spreading. There's a lot of native varieties of that. Um so that those are just uh a few a few mentions there.
SPEAKER_01So when we talk about something like a red bud and we got the straight
Cultivated varieties
SPEAKER_01native species, what if I grow flamethrower or forest pansy? Am I doing something negative to the pollinators compared to the straight species, or does the pollinator get what it needs off some of these cultivated varieties, or is it case by case?
SPEAKER_00Yeah, so when it comes to the pollinator itself, there's and you know, once again, this is the one that's using the nectar and pollen. Um, there's little evidence to show that cultivated varieties offering similar rewards for pollinators have any negative effect. Uh, however, if we're talking about the larval forms, things like the uh what was it, the forest pansies um variety has a red leaf, I believe. Um often those are filled with anthocyanins, which happen to have a negative effect on herbivorous insects. So um any of those uh larval forms of moths and and butterflies utilizing red butter, not going to be able to easily feed on a cultivar with those red leaves that instead of green. So I try to avoid those if you're trying to support those larval forms.
SPEAKER_01Well, that's good to know. So I want
Adam's career
SPEAKER_01to uh talk to you a little bit about how this became your job. Uh and and did you always love insects, or did this somewhere in school did you uh figure out this is what you wanted to do?
SPEAKER_00Um yes, I was a kid. I grew up in in rural Michigan, and uh there's a bog in our backyard, and I spent lots of time uh catching turtles and and frogs and stuff like that, and was always interested in insects. Always wanted to be a naturalist when I was a kid, and uh after high school, I ended up getting involved in the wine industry. There's a big wine industry where I grew up, so I worked in that for several years before going to college. And then uh as I went to college, I was pursuing a degree in environmental journalism and and nature writing. So um, while I was pursuing that, I ended up taking some entomology courses. Forest entomology was the kind of the first one that sparked this and uh created this career path for me. So uh during that class, uh, that was uh forest entomology, was the Dr. Lynn Risky Kenny at University of Kentucky. Uh, I got a job in her lab, and our first project was looking at some of her graduate student Chris Strome's uh projects, where we're looking at asking the question of how uh stream invertebrates would be affected by a transition from hemlock to a deciduous canopy. So hemlock William Delgred was coming in at that time and sort of look at the different feeding guilds with inside the streams. And then after that, I I got a undergraduate position as a research technician in Dr. Dan Potter's lab, um, who uh was famously uh responsible for a lot of the work on a lot of the ornamental tree and shrub pests and turf pests, and he was sort of transitioning into a pollinator-related program at that time. And as I graduated, a position opened up in his lab uh leading to uh PhD in entomology.
SPEAKER_01Do you feel that
Are pollinators declining?
SPEAKER_01in general pollinators are on the decline? Can we say that or not?
SPEAKER_00Uh there's a lot of evidence that insects in general are on the decline. It's sort of this perfect uh storm of uh loss of habitat due to urbanization and fragmentation, doing due to large monoculture cropping systems, due to pesticide use, due to climate change, and leading to phenological mismatch with host plants. Um, so certainly there's a lot of tough places. As you can imagine, almost every urban area, it's pretty tough to be an insect. Um, so protecting those spaces that we have naturalized, utilizing our own properties as habitat and providing resources is pretty important so we
Identifying species to support
SPEAKER_00can keep this diversity thriving.
SPEAKER_01If my landscape is organic, if I'm choosing lots of different native plants that bloom at different times, that's one step in the right direction. If I was a homeowner and told you that, what else would you tell me to do?
SPEAKER_00Um, one thing that I like to do is identify certain species of interest that you would like to help support. Um, you can't save every every insect or every bird or every pollinator on your own property, but you certainly can help support a few. It also leads to this ecological storytelling, right? You know, there's a lot of these instances where people plant a pollinator garden. It's like, well, we planted flowers to support pollinators, end of story, right? Well, if you can pick specific species that have a you know certain depth of their nectary that support uh bees with certain tongue lengths, often there's this strong relationship between form and function between flowers and bees. So the depth of the nectary often informs the type of bees that you're able to support, right? So if you want to support small native bees like sweat bees and and um colletted bees, they're like the cellophane bees or mast bees, you may be choosing different things than if you're interested in supporting bumblebees, which leads to engagement with your property, which leads to conversation, and which leads to an overall love and appreciation for nature, for your friends and family.
SPEAKER_01Well, Adam, I'm gonna leave it right there. It's fascinating. Thank you so much for sharing your expertise. I'll tell you, that was great. I learned so much and look forward to talking to you again.
SPEAKER_00Always happy to come on. Thanks for having me, Doug.
SPEAKER_01Always great to talk to Adam. He's got some pretty cool ideas of some future podcasts. So I'm looking forward to that. Now, tune in every Thursday to the Talking Trees podcast from the Davy Tree Expert Company. I'm your host, Doug Oester, and do me a big favor, subscribe to the podcast so you'll never miss a show. And we'd love to hear from you. A couple different ways to do that. Send us an email to podcasts at dvy.com. That's podcast at d A V E Y.com. You can also click the link at the end of our show notes to text us a fan mail message. Your ideas could be on a future show, and as always, we'd like to remind you on the Talking Trees podcast, trees are the answer.