Talking Trees with Davey Tree
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Talking Trees with Davey Tree
Early Leaf Drop: Is This Supposed to Happen?
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Mike Cassidy from Davey's West Columbus office joins us to talk about early leaf drop, including the stressors that cause it and what you can do to help prevent it.
To find your local Davey office, check out our find a local office page to search by zip code.
To learn more about early leaf drop, please read our blogs See Burnt Tree Leaves? Fix Leaf Scorch Symptoms with Treatment, Why Are Trees Losing Leaves in June, August or Early Fall?, Reasons For Early Or Dull Fall Color and Why Some Trees Change Color Earlier Than Others.
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Welcome to the Deby 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. Well, he's back. Mike Cassidy is a sales arborist for the Debut Tree Expert Company in Columbus. And we've done a lot of fun podcasts together. We like to refer to him as a character, and uh he might throw out a few jokes and you'll hear crickets because I won't understand that he's joking. But we're gonna have some fun today. But we are talking, Mike, about uh early leaf drop on trees. How are you? And uh let's start uh discussing our early leaf drop problems.
SPEAKER_00Well, Doug, we're underwater here in Columbus. I'm running sales calls in my waiters right now, so it's about how things are here. How is it in your area? You swamped?
SPEAKER_01Absolutely, but I just wrote a column today, The Secret Life of Gardeners, who we when it rains, you're around all these people that are like, oh, it's raining, it's raining. And the gardeners, when they get together, they're like, it's raining, it's raining. But you know, before we get to that early leaf drop, let's talk a little
Heavy rain affecting trees
SPEAKER_01bit about that. Because uh, in much of our area, he's down in Columbus, I'm up in Pittsburgh. It's been a weird season. I've never had, you know, in my 40 years of doing this, I've I've never seen a season like this where I don't think I've watered anything maybe since the end of May.
SPEAKER_00I'm trying to think of when I had to water last because I I have a guard in the back, and and uh yeah, that sprinkler's been off for a long time, I'll tell you that. I I I think uh all my cherry, I had a lot of cherry tomatoes crack, and I blame this most recent storm from pumping them up too hard.
SPEAKER_01Oh, there's no doubt about that. That you know, there's no way you're gonna stop tomatoes from cracking when you got this kind of rain. They just can't take it. You know, that's what happens. It rains, the plant absorbs the water, it's like, oh, this is so great, and the tomato's already there, and it's like that's too much. Yeah. But it's okay. It's okay. The weeds, though, the weeds have been nuts, though, with the with all this rain, too.
SPEAKER_00Oh, and getting out and treating or getting out and mowing. And I mean, everything's everything's a battle these days with how much. I think we've had 10 inches of rain here in the past couple weeks. I mean, it's been it's been crazy.
SPEAKER_01How about for the trees? Does this affect them in any way? What are you seeing out there?
SPEAKER_00Well, I'm seeing a lot of trees laying on houses, so it's definitely affected them in that way. You know, they're they were much more vertical before we've had all these storms. Um, a lot of cracks right in the middle. So we're kind of you kind of caught me on an exhausting period here where we're just I mean, I woke up last night here in the rain, and I was just like, not another day. Doug needs me tomorrow. You know, I I can't I can't do this again. We got crews up from West Virginia, and we are just trying to keep our heads above water.
SPEAKER_01Um you getting a lot of like soft ground where something with shallow roots might just fall over.
SPEAKER_00Is that especially with you know your white pines that have always been always had their feet too wet? I mean, we see those things tip over like nothing. Um kind of changes your perspective when you're looking at a house. You know, I'm an arborist, I love trees, and I don't know how how much I want to live in a wooded area. You know what I mean? It's just it's it's risky, man. I you see trees that you're like, oh, that tree will be fine. Next week they call you and say it came down, you know.
SPEAKER_01Mike, I don't want to hear that. I live in an oak forest. No, you do, I know you do, and it's very worrisome. Uh, but that's you know, I I have uh my Davy, not my Davy Arborist, the guy who I work with at Davy. He comes all the time, takes a look, but you just never know with these anomalies and weather. Uh, like I said, this is a season that I've I've never seen anything like this before. Now I talked to somebody from Michigan the other day, they were like, oh man, we wish we had some rain. So you just you just don't know. Yeah, I guess you just gotta be happy with your gifts. I'm tired of being wet. Yeah, I hear you. I hear you. My my dog, my dog is tired of being wet. I take the dogs out in the garden and it's it's so overgrown, it doesn't matter where you're walking, you're gonna you're gonna end up when you come back, you're gonna be wet.
SPEAKER_00So yeah, well, uh, such is life. I guess you dig a little moat.
Fire blight
SPEAKER_00Um you know, oh this overwatering and and uh saturated soil can cause early leaf drop in trees.
SPEAKER_01Yeah. Are you seeing it?
SPEAKER_00I don't think I've seen any early leaf drop yet that I fully attributed to um anaerobic conditions in the root zone. But I am seeing, I'll tell you what I've been seeing a lot of this year is is fire blight. It has been like outrageous in central Ohio. The fireblight has just been hammering everything, every pear, every crab apple. Um, you know, that's a little different than your early leaf drop. We expect to see more shepherds cooking and die back kind of um in different areas on the trunk, but that's been the big pest this year.
SPEAKER_01You know, that's the one that let's talk about fire blight, what it is, and uh how how terrible it is. Uh yeah when you get it into your garden. Uh you know, and is it just because of all the your wet conditions you're seeing so much fire blight, you think, or is it something else?
SPEAKER_00I don't know. I think it seems like every year there's one, and I misspoke when I said it's a pest, um, but you know, it's it's a bacterial infection. But I uh I think conditions seem to be right every year for one big thing. You know, a couple years ago it was Volutella in the boxwoods. Uh maybe even a little bit sooner than that was Magnolia scale. Um now this year it's fire blight. It just seems that that every year there there's one thing that it's just conditions are perfect and it takes off. So um, yeah, I I don't I don't attribute it to anything specific, I guess, just that it's it's its chance to shine here. We're getting fireblight conditions.
SPEAKER_01What's it look like and what does it do to the trees and which trees are affected?
SPEAKER_00So I'm seeing it mostly in crab apples and pears. That's the my number one and two uh suspects, but you'll notice a limb probably half inch in diameter, especially out towards the tip, you'll have dieback from the top from the tip back about maybe two to three feet, and it'll be the classic shepherd's crook kind of curling at the tip. And then all those leaves brown out, but they don't seem to fall off very quickly. And uh these are indicators it's probably time to test for fire blighty. You might have fire blight. And uh the treatment is very similar to like a leaf disease, you know, that could cause a more broad early leaf drop. Uh the timing's a little bit different, but it is like a uh spray, a couple sprays in the spring during the wettest time of the year. So, you know, it's a it's a proactive, not a reactive treatment. We can't really do anything once once we get it, we just cut the tips out, but next year we can kind of uh try to prevent it a little bit to stop it from coming back.
SPEAKER_01Well, you know how everybody tries to get you to diagnose things when you can't see them.
SPEAKER_00Oh, yeah.
SPEAKER_01Well, I have I'm looking out my window and I've never seen my hemlocks with this kind of coloration on them. There's like some branches that are really pale and yellowish, and I don't know if that's hemlock will be adolgia or if that's just they're too wet. Oh, I don't know what's going on.
SPEAKER_00Well, I'll tell you, where I live, hemlocks just are not happy. Um, they just don't do well generally. So that is what I would expect to see out of a hemlock in central Ohio. But certainly what you're describing sounds like it could be due to uh abiotic conditions, uh, you know, in this case, over too much water, too much wetness. In evergreens, you know, I expect to see that yellowing um and that dieback when they are anaerobic conditions deep. Um yeah.
SPEAKER_01You know, I'll take this over a drought any day. Last year, I don't know how you guys, your season was, but our season was I think it was maybe at least four weeks, but maybe six without rain. And for anyone growing anything, trees, vegetables, flowers, that was no fun.
SPEAKER_00Well, I have a I have a dire premonition that that September we're gonna be standing on cracked ground again. I I just I have a feeling in my bones that we're coming up on a big drought. Um, because it seems like the drought keeps getting later and later in the year. And last year it was September, I think that we didn't get really any rain at all. So uh don't put don't bury that sprinkler behind the Christmas decorations just yet.
SPEAKER_01So let's talk a little bit about our subject.
What causes early leaf drop?
SPEAKER_01We've been uh we've been gabbing here. Mike and I like to do that. So, what are some of the other things that cause early leaf drop and and how concerning is it?
SPEAKER_00Um, it's pretty common for me to get calls where trees losing leaves early, come out and take a look. Um this is usually uh to me an indicator that something's happening more than you know, it's kind of the beginning of the process of diagnosing the tree's issues. Um, leaf drop can be caused by really, you know, overwatering, drought, pests, disease. Um we had a lot of we had a lot of uh leaf loss earlier in the year when we had hail storms. Um, but the results looked very similar to just early leaf drop, you know. So I'm still visiting properties where the limb's still alive, but it's exhibiting early leaf drop. And I say, was your lawn full of y leaves here, you know, in in May or April when we had those big storms? And if the answer is yes, well, that's good news, that's kind of a well, just see how she does next year. Um, but you know, when the issue with early leaf drop and overwatering is that conditions low are anaerobic, there's no oxygen to the soil, so they can't push those nutrients up and the leaves fall early. Um, so it's really it just depends on what the underlying condition is. Because if it's too wet because of rain, well, you're getting early leaf drop, it'll probably be fine next year, you know. Um drought similarly can cause early leaf drop because everything's just drying out and falling off as petioles are dying. So we say, you know, you can do something about that right now. You could water. Um separately, if you're always having overwater issues or if soil conditions are always anaerobic, it could be that you need to try to adjust the soil composition through a process like vertical mulching, you know, blasting holes in the soil and dump backfilling with biochar or sand or a material that's going to help with that drainage if you have a heavy clay soil. Um, so you know, we might look for a more mechanical solution. But another huge
Leaf diseases
SPEAKER_00leaf drop call I get is for ornamentals like um hawthorns or crab apples getting leaf diseases.
SPEAKER_01Yeah.
SPEAKER_00I mean that's huge. And especially as they get older or in neighborhoods where it's just either traveling through shears from landscapers that work down the street, or you know, whatever the underlying cause is, it is super prevalent. And it's almost you can go out to a property if you got a 20-year-old crab apple and you live in a neighborhood, it's just time to start leaf disease treatments. You know, it's it's going to affect the vigor of the tree, the health of the tree long term, and you're gonna get that early leaf drop. And it's just suboptimal when you got this tree that flowers for a couple weeks and then the leaves are gone in July. Um, you know, you're cleaning up your yard early, you're all the things that are associated. Um, one thing I always make sure to tell homeowners when it comes to leaf disease is get those leaves out of the bed at the end of the fall, you know, because those spores will stay active and then they'll return back up to the tree.
SPEAKER_01Um so for like for like the a treat like a crab apple, I'm
Apple scab
SPEAKER_01assuming that's apple scab, or could it be something else?
SPEAKER_00Yeah, it could be apple scab or some kind of rust. Um, but applescab is the big one.
SPEAKER_01When do we treat for that? When are we supposed to treat for that?
SPEAKER_00Yeah, so uh right around bud break as stuff starts to swell, uh, we go out. Now, I always tell people if Disney World has a bunch of crab apples, which luckily I haven't had to go yet with my son, but if they got a bunch of crab apples, they're probably treating them every couple weeks all the time, all the time during the growing season. They're just you know continuously spraying these things for leaf disease. Um, for homeowners, you know, that could be obviously super expensive. So, what we found is if we do three three treatments in the spring from bud break and then 14 to 21 days apart after that, we capture the most active times of the fungus and we can greatly reduce the leaf disease. Um, you know, for older trees, it's harder. If there's any other underlying issues in the tree, they'll be less likely to resist it, even with fungicides. But that's kind of the rule of thumb is the three in the spring.
SPEAKER_01And if an older crab apple is losing its leaves every year, that's not going to be a good thing for the health of the tree, right? Exactly. Yeah.
SPEAKER_00Yeah. I mean, you know, you kind of gotta make that decision too. Once you start losing bigger limbs, is it the leave disease or is it just time to get her out of there?
Planting crab apples
SPEAKER_01Um I I've asked this question before. Tell me what you think. I have a really failing crab apple. It's been hit several times by other trees. Davey has kept it going, they've pruned it. You know, he doesn't like it, but I'm like, hey, I have this tree has minor sentimental value. I want to keep it going. It has one little stick of a of a uh left. And I'd like to put another crab apple there. If I buy a newer variety, is it gonna do better to fight off the disease, or should I consider it, should I put a different tree there? I want to see it out that window where I've been looking at it for 30 years.
SPEAKER_00LL tree salesmen sure will tell you that they have crab apples that are resistant to leaf disease. Now I now they also will say, what can I do to get you into a crab apple today? So it's a little bit of a I love it. It just depends on how bad it is. You know, if if site conditions are good for a crab apple and you're gonna keep the leaves up and it's not too wet or whatever, and you know, everything else consistent, you could think about putting another crab apple there with the understanding that you're probably gonna end up having to treat it. Um but when it comes to ornamental trees, there's a lot of issues associated just generally, so you kind of got to make that decision unless you want to put a red bud there, and then that thing will survive, you know, a nuclear war. So um, you know, there's just there's just bad things associated with trees, especially I kind of think of them like Dalmatians sometime, right? Like they've just been crossbred and and changed so many times that they're willing to run into a fire. You gotta think that like, you know, you're gonna have some issues when we've screwed with them so
Red buds
SPEAKER_00much.
SPEAKER_01Tell me about your opinion of like a flamethrower red bud, one that like has foliage with all these different colors, or even forest pansy. You have you had good luck with them? Have you seen them? Have are you planting that kind of crazy stuff?
SPEAKER_00So if someone if that's a first choice and they're interested in a red bud and they want those unique ones, I'm more uh willing to suggest those and plant those. And you know, the customer's always right in matters of taste, so sometimes I can't talk them out of the crab apple or the blue spruce. But um, I use a red bud in situations where something won't grow here. Like we've had issues with multiple varieties of trees, and that's when I'll go for like the standard old you know, Circus Candenses and say, just dump this thing in, and this is your best bet. You know, we're in a new development and there's three inches of topsoil, and then it's all gravel below that, and it's like, well, these girls seem to grow, so give this one a shot. But uh, you know, I I sometimes I fail to talk people out of the less resistant trees.
SPEAKER_01You know, somewhere in there, I think you said uh inferred I don't have any good good taste.
SPEAKER_00Oh well, I won't go that far. You know what I mean? I haven't been to your yard yet. Maybe next time when we record live, I can really give my opinion on if you've chosen the right varieties or if you just need to start over. Oh, it's gonna be ugly.
SPEAKER_01Anyway, let's go back to leaf drop. Uh, how
Oak wilt and other diseases
SPEAKER_01about the diseases? There's a lot of a lot of other diseases that leaves can drop. And from in my case, I I I'm a broken record, but oak wilt has found its way into my forest. And if I see those leaves and they've kind of turned a bronze color and dropped, I'm calling the Davy Arborist right away. I want a test to see if this tree actually has the oak wilt. But are there other issues like that too? That can be a lot of people.
SPEAKER_00Well, certainly anything that's gonna kill the tree, like an oak wilt, a Dutch elm disease, um ash borer, bronze birch bore, all of these things are going to cause leaf drop. And that's kind of the issue when you get a call that's like leaves are falling, it's like it could be anything, you know what I mean? Um, because that's kind of a sign that the tree's declining generally. Um but yeah, we there's leaf drop associated with all fatal diseases. I got a quick question for you. Are you when you remove these trees with oak wheel, do you trench out the root system like to avoid root graft transfer?
SPEAKER_01No. Uh right.
SPEAKER_00Because that would be such a mess.
SPEAKER_01Yeah, and right now the driveway is is stopping that from happening for the time being. But I mean, I have so many huge old oak trees, just cutting them down is is killing me. It's it's killing my whole my whole budget for for my house. And and uh I'm losing, you know, I'm losing one or two a year, and I'm replacing them. I'm replacing them with other things, natives and other interesting trees. Uh, that's where I get a lot of suggestions, uh, good suggestions from guys like you, Mike. Uh, even though you do say I don't have any taste, good taste, but uh you know it it's it's just one of those things where you you you you're upset that you have it, but what are you gonna do about it? Uh if I had two oaks, it'd be no big deal. Cut them down, take the wood, take them out of here, trench them, uh, and and you'd be done. But when you have four acres of old growth oak with all sorts of other things, hickories and sassafras and maples and everything else, uh you you've got to you've got to make a decision between yourself and the arborist, and that's what I I enjoy is being able to have somebody that I can uh run these ideas uh up with and say, what's this gonna cost? What do you think I should do? Should I treat this one? Should I continually treat this one? And it's just it's a case-by-case basis, but that's why you need to to have an expert. Uh uh it it makes everything much easier. And I I just have to assume when I get to the end of August, when I get into September and I start to see leaves dropping when they shouldn't be, call your certified arborist, right, Mike?
SPEAKER_00Yes, get somebody out there to identify. Sooner rather than later, right? Yeah, yeah.
Magnolia scale
SPEAKER_00Um well, one other thing I want to talk about with uh early leaf drop that is uh more identifiable without a professional to be there to look at site conditions and stuff, are there's some pests that will cause early leaf drop. Um, and and these are easier to identify just with looking at them. You know what I mean? Um in magnolias, especially, uh there's a lot of different kinds of scale, and they can hit maples and crabs and everything else, but I've noticed a lot of uh magnolia scale recently, and that's very visible on the tree. You're looking for white, it's like white circles that are usually larger than an eraser head, um, and they'll spot the tree all over. And the more you get, the more it's a sap-sucking insect, so the more vigor, the more sap they're sucking out, um, and the more early leaf drop that we associate with that. So that's something you can notice. Um,
Spider mites
SPEAKER_00spider mites. I know I had a lot of early leaf drop on burning bushes last year from warm season uh spider mites. That's something that you can notice. You can see the webbing sometimes, you can see the stippling. Um, warm season mites specifically are an interesting pest to try to manage because depending on the size of the population, they can have an they can you know create generations every seven to fourteen days if conditions are right. And they become very quickly resistant to the mitocides we use. So we have to use uh you know rotating products every seven to fourteen days for an extreme uh infestation to treat. So those are great to get early. Um, you know, if you can notice the stippling on the leaves, which is like little dots where they're sucking it out or or webbing. Um, these are things that you can kind of key in on to understand that it's not maybe environmental conditions, uh it is the uh you know the pest doing it. Also, if
Sprinklers
SPEAKER_00you do have crab apples and you're experiencing a lot of leaf disease. Paying attention to sprinklers if you have irrigation is such a big deal. If you are keep if you are continually keeping the leaves wet with a with an errant sprinkler head or the trunk wet, you're just really creating the conditions necessary for those fungal scores to populate and spread. Also, a tree that's too thick, you know, if you're not getting it pruned and the crab apple is just completely dense, all that interior foliage is staying wet and it's staying dark, and you're creating conditions that are better for the fungus. So these are things that you can kind of be proactive on, um barring any site issues where you got it in a swale and it's just getting hammered and it's you know wrong tree, wrong place, basically.
SPEAKER_01Well, it all makes sense, Mike. And before I let you go, we gotta we gotta leave the tree world and talk about some other things. I used to feel the same way about Disney that you do. Until until I actually went. Uh, and I'll tell you what, uh, they know how to do it. And so don't don't fear that, don't, don't uh resist that, okay?
SPEAKER_00Wow.
SPEAKER_01And then secondly,
Mike's garden
SPEAKER_01tell me about your garden. What's going good in your garden before I let you go?
SPEAKER_00Sure, yeah. So uh this year the big crop has been squash, uh crookneck squash, and kind much to the chagrin of my wife, she is so sick of cooking me squash. Uh I just keep bringing them in, and I she makes this like puree that's squash, potato, and onion, and I just put it in a big jug and drink it all day, and she is just grossed out to no end. Um squash are huge, huge cucumber crop this year, but those have since all died. Um, eggplant, you know, I wish I could grow gummy bears and bread. Because sometimes when you're sitting there looking at a huge bucket of eggplant, you're like, we gotta you just gotta get through them. It's sometimes kind of a slog, you know it.
SPEAKER_01Um I interviewed a young woman who uh she won like a garden award and she had all these eggplants in the garden. I said, Do you like eggplants? She goes, No, I don't eat them, but I just think they're beautiful.
SPEAKER_00They do look good, yeah. They they're you know, beautiful purple flowers come out, but then at the end you just got an eggplant.
SPEAKER_01Just remember, gardening is also about sharing. Everywhere I go, I'm taking hot peppers because I'm overrun with hot peppers. Everywhere you go, you should be taking squash and eggplant with you, and people will appreciate it because they don't they don't get the fresh produce that we do as gardeners.
SPEAKER_00My mom stopped taking eggplants, uh stopped taking eggplants and squash. That's how I knew I had too many because she was like, I'm I'm tired of acting like we want these, son. You know?
SPEAKER_01All right, Mike. Hey, it was great to talk to you again. Always enjoy our time together. And especially since you've been so busy with this weather, appreciate your time, and I can't wait to talk again. Thanks.
SPEAKER_00Great to talk to you, man.
SPEAKER_01Well, Mike has too many eggplants and squash. I have too many hot peppers. There are worse things that could happen to a gardener. There is an old joke, though, that if someone stops too long in front of your house, they will get a back seat filled with zucchini. Now, tune in every Thursday to the Talking Trees Podcast from the Davy Tree Expert Company. I'm your host, Doug Oester, and as always, I'd love for you to subscribe and let us know what we should cover or what you think of the show. Send us an email to podcasts at Davey.com. That's P-O-D-C-A-S-T-S at davey.com. You can also click the link at the end of our show notes to text us a fan mail message. We'd love to hear from you. And as always, we like to remind you on the Talking Trees podcast. Trees are the answer.