GB 120 TRANSCRIPT How a Tree Works. Dahlias.
28:25
SPEAKERS
Pam Bone, Mary in VA, Farmer Fred
Farmer Fred 00:00
Farmer Fred 0:00 Garden Basics with Farmer Fred is brought to you by Smart Pots, the original lightweight, long lasting fabric plant container. it's made in the USA. Visit SmartPots.com slash Fred for more information and a special discount, that's SmartPots.com/Fred.
Farmer Fred 00:20
Welcome to the Garden Basics with Farmer Fred podcast. If you're just a beginning gardener or you want good gardening information, you've come to the right spot.
Farmer Fred 00:32
Trees. They're subject to many problems, including insects, diseases, and weather-related issues, but probably the biggest threat to the trees in your yard... is you. From the day you plant that tree until its demise, you may not be helping it live a healthy life in many, many ways. Master Gardener and Urban Forester Pam Bone talks about how a tree works. And what we can do to keep it healthy by knowing how your trees actually function. We'll be answering your garden questions as well. It's on episode 120 of the Garden Basics with Farmer Fred podcast, brought to you today by Smart Pots. And we'll do it all in under 30 minutes. Let's go.
Farmer Fred 01:16
Did you ever wonder how a tree works and what you do to that tree may affect its life? In fact, there are some who say that the reason trees die is basically your fault. Because you might be hacking away at it, and not even knowing it. How's that? Well, we'll explain. With me is Pam Bone, Sacramento County Master Gardener. Also, in a former life, an urban forester. And she knows trees. She's part of the Sacramento Tree Foundation, as well. And Pam, let's talk about how a tree works. And when I'm talking about injuries to trees, well, that can certainly affect the life of a tree, especially if you've got a weed whacker, or a mower or even even a high impulse sprinkler, hitting the trunk of the tree. It could be damaging it.
Pam Bone 02:02
Definitely. In fact, let me explain to you about woody plant anatomy. However, the first thing I'm going to say is that let's just look at a tree. What is a tree? And by the way, this applies to woody plants in general, shrubs as well. But we'll just say with a tree. We have the crown of the tree, which is the head. You know, how sometimes you call your head the crown. Well, that's where the leaves are. And that's where photosynthesis is taking place and the plant is making its food. And then we have the trunk or the stem, the woody portion, and I'm going to talk about what's inside there, and all the stuff that it's doing. And then we have what's called the root crown. And the root crown is where people get confused. Sometimes you'll see a crown and you're not really sure what they're talking about. The root crown is just where the roots go into the ground. It's kind of the top of the root ball in a container. And then it's sort of a flaring area where it flares into the ground, or at least it should look like a flare going into the ground. That's a discussion for another day. When it looks like a telephone pole going into the ground, that's not good. So basically, that's just kind of what a tree looks like. So now let's get into the anatomy what's going on inside, that affects what you were just talking about, the practices that we might do to trees and how we can injure them. So first thing we have is the bark. And the bark is really critical because it helps to defend against diseases and insects from getting in and protects against water loss from getting too hot, too cold. And so it's kind of like the tree skin. And so it's really important to have an intact bark. And then just inside the bark is a tissue, a fancy tissue called the phloem tissue. And the phloem tissue is the transportation from the top of the tree, that crown I was telling you about. And it's transporting all of that food, the carbohydrates, like sugar and starches, that were made in the leaves. And then it's transported down throughout the plant into the trunk and eventually down to the roots. So then, inside that tissue is the most important tissue of all in a woody plant. It's called the cambium. And some people might be familiar with the cambium if they've ever done budding and grafting or if they've ever looked at a plant in the spring, and we talk about that the bark is slipping, and that happens this time of the year (spring). It's kind of slippery underneath there and that's where the cambium tissue, which is only about one cell thick, and it's actively dividing tissue. We call that meristematic tissue and it's where cell division takes place and it forms the flow of tissue. Remember that transportation from the root or the the top of the tree, the crown down to the root area and it It forms the phloem to the outside. And then towards the inside, it forms what we call the xylem. Or some people call it the sapwood. And this is the new wood that transports water and minerals from the roots, and then goes back up into the tree. And that xylem or sapwood only is about maybe 20 cells, depending how old the the tree or the plant is, about 20 cells thick, that's really actively taking water and minerals from the roots and moving it up. The rest of it turns into that heartwood you know, the woody part of a tree, you go knock knock knock on a tree, and you can hear that that wood, well, that's the heartwood, made up of xylem tissue that's no longer active in transport. And so then you go, well, why is all this important? Why do I need to know what's going on in there? Because if you take a tie, for instance, you're staking a tree, and you tie it up and you leave the tree tie on. Pretty soon, the tree keeps growing through that sapwood or xylem, it gets bigger and bigger making growth rings every year. And what happens is that tree tie pretty soon cuts into the trunk of the tree, then it cuts off the sugars and the starches being transported in the phloem. And then pretty soon, if it just keeps growing, it cuts into that cambium tissue. And once it cuts into the cambium, you can no longer make any more flow and transport you can no longer make any more xylem. And pretty soon the tree then usually runs out of water. In fact, a lot of times when you have injury, whether a tree has been hit by a car and there's a big hunk off of it, or an animal's chewed through it, or you put a tree tie around it, or you have roots that maybe circle round and round at that root crown or down below. And they literally choke off the tree from transporting the water. And you know what the first thing that people say with any of this stuff, oh, the trees drying out, I need to put more water on. And that's the first reaction when you see the top of the tree looking as if it's brown and dying, or the leaves are off colored like they don't have enough fertilizer. Either throw the fertilizer on or you throw water on. But you have to be more of a detective and find out maybe something is going on with that tree, inside that trunk or that stem or that branch. And so this is really important to understand the anatomy of a tree.
Farmer Fred 07:36
Alright, let's back up and talk about the proper way to stake that tree. It's not uncommon, it's an unfortunate sight, in neighborhoods, when people buy a new tree, they'll leave the stake that came with the tree right next to the tree, tightly bound around that tiny little stake. Do you need to stake a tree at all once it's planted?
Pam Bone 08:01
Well, if it was grown in the nursery without a stake, you'd never have to stake that tree. Unfortunately, for many different reasons. And the nurseries have reasons sometimes for economics, and you can get a tree that's a little bit taller a little bit faster. By putting a stake on it, it's easier for transport, it's easier for storing it in the yard and moving it around. But you don't have to leave the nursery stake on. That should never be left on. In fact, we have this two stake method where you stake on either side of the tree. And I have seen people using properly that two-stake method and yet they still leave the nursery stake on, and here's the problem. You leave the nursery stake on and you've got two problems. Remember I was just telling you about the woody plant anatomy? Well, those little tree ties rub rub rub against the trunk there, and also so does that little stake, and you get an injury to the bark. And then pretty soon borers can get in, you can get fungus that can get in there, or you start killing off that transport system that I was talking about that's inside the tree. the internal plumbing of the tree then is disrupted. That phloem, cambium and xylem. So no, you never want that. The other thing is interesting enough: trees need to move. And if they are restricted and they can't move, all kinds of negative things happen. And one of the biggest things is their roots don't grow properly, and they don't grow fast enough. And so the tree becomes very weak and dependent. It's kind of like having your arm in a cast. If you left your arm in a cast forever, and then finally tried to take the cast off, you've got this puny little arm that's quite weak and you've got to do some exercise. Well, trees need exercise too. So for both reasons, we don't ever put on a nursery stake.
Farmer Fred 09:56
All right. Now about the two-stake method. And frankly, you only need to stake a tree if it won't stand up by itself, and you use that two-stake method. And I think the key to securing it to those two stakes is to make that figure eight loop with the tree ties or tree tape, and not choke the trunk of the tree right off the bat. Keep it loose, to allow room for it to grow. And then only keep those stakes on for what, maybe a year at most.
Pam Bone 10:24
Yes, you need to find out if there's a reason it's not standing on its own after a year, maybe you staked it too high and it didn't get to move enough. Maybe it's got a restricted or poor root system, there's lots of things going on. I do want to go back to the figure-eight actually. With the university, we used to always recommend doing a figure eight and then we found out that it was kind of like a little fulcrum point there where it could rub against the trunk. So what we recommend now: it would be better if you could take that wide tree tape or you know, some people use tire material, those staking ties that you can buy. I used to use old nylons, you know, the pantyhose or the nylon knee highs, they worked great when people used to wear those. They don't anymore. What you do is, you go from one stake to the tree and back to the stake. And then on the other stake, you do the same thing again. And so then you don't have a figure eight that could maybe cinch up or tie or make a really tight little area there that could rub. And that makes it just a little bit safer for the trunk of the tree.
Farmer Fred 11:28
But as you pointed out earlier, if that tree tie is left too long, it could be digging in even if it's only digging in on one side of the tree. And then you your might be choking off the plumbing system for the tree.
Pam Bone 11:43
Exactly. And in fact, I have photo after photo after photo. I teach a lot of classes to master gardeners about tree care. And I have so many slides on improperly staked trees. And a lot of girdling where the tree ties are literally embedded inside the trunk of the tree and there's no way of getting it out of the tree. It is eventually going to die. Sometimes it takes a long time to die because it has to use up all the sugar reserves, it has to use up all the water that's stored in there. But eventually it will die. It's gone all the way around the tree and choked it off, basically and cut off all of that transport system. So unfortunately, tree ties can be really serious problem. Tree stakes can be a serious problem. But sometimes it's necessary. And if you don't understand quite how to do it, you should go look at an illustration, two stakes on either side of the root ball with the tree ties coming from the stakes, far enough out on either side of the root ball so that then the tree can move back and forth in the wind, which is really important for strengthening in the tree trunk and increasing the root system and just lots of good benefits from movement. But you don't want it moving so much that it whips around and you've got a tree stake that's so tall that the tree then beats itself against the side of the stake. That's another thing. You want to put those tree ties, only at the lowest point that the tree will actually still remain upright, so that the tree can still move back and forth. Obviously, if you stake it, and you stake it too low and the trees still leaning to the side. Well, you've staked it too low. But you can also stake too high, too. And then the tree doesn't even get to move at all. So there's a little bit to it. It's pretty easy, but I see lots of still lots of problems. Research was done on this actually at the University of California. And this research was done in the late 60s and the 70s. And unfortunately I still see a lot of improper staking.
Farmer Fred 13:44
We'll have links in today's show notes on how to properly stake a tree and videos as well on how to do it, from the Sacramento Tree Foundation. So look for those in today's show notes.
Farmer Fred 13:59
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Farmer Fred 14:58
Let's get back to our conversation with Pam Bone, Master Gardener and urban forester, about the damage we're doing to our trees that we may not know we're doing. And one of the areas of great concern are tree ties. And sometimes when ties are left on a tree, tied to a stake for too long, the tree will actually grow over that tree tie, or that tree tape, and people think, "oh, the tree has healed itself. I don't need to worry."
Pam Bone 15:27
No, unfortunately, what's happening is as I described earlier. That xylem, that woody tissue that becomes heartwood. Xylem tissue is what makes a growth ring every year. And that grows. It gets bigger every single year. The material that I talked about earlier, the phloem tissue, it just kind of sloughs off in the bark every year, and it never gets really big. But the xylem tissue just gets bigger and bigger and bigger and keeps growing. And so you've got a stationary object. I've seen extension cords, I've seen strings, we know fences, you know, how many times have you seen out in the country, a tree that's sitting there, and somebody's taking their wire fence and wrapped it around the tree as a as a support for the fence. And pretty soon, I've got picture again, picture after picture. I even have rebar inside of a pine tree up at Lake Tahoe. And what it is, is the tree keeps growing. And pretty soon, you're right, it just surrounds that and grows around it. And you see a lot of excess growth. And that's just the tree reacting to it and going and making all this extra growth around it. But unfortunately, what's going on inside that you can't see is it's just starting to cut off all of the water and sugar transport system. And pretty soon the tree is either gonna starve to death, or it's gonna run out of water and it will die.
Farmer Fred 16:50
Exactly. This isn't a sudden death thing. It takes years and years for it to happen. So even though you may see a a tree, a tree tie or tape or rebar that has been engulfed by the tree, the tree is still not functioning normally and its days are numbered.
Pam Bone 17:11
And in fact, you can look at a tree. Actually, I had. I was asked to go out on a call for one of the master gardeners and they had a beautiful Holly tree, just gorgeous. And they said you know we've had this Holly tree and for at least 25 or 30 years, and all of a sudden the last few year,s the top of it just doesn't look good. It's a little off color. The summer months when it's hot outside, the leaves look a little bit scorched and brown. What's going on? Pam, can you take a look at it. It took me a little while to find out, because it was barely sticking out. I searched all the way around. And I found a green tree tie, just maybe the last half inch of it still in there. And they said, Oh my gosh, that had been there for 20 years. But it had taken that long for it to finally cut through and literally cut off so much of that SAP wood or xylem tissue that water could not transport during the hot summer months, there wasn't enough of it. It's kind of like taking a garden hose. And you know how if you don't have one of those nice shut off little nozzles on it, and you would just crimp the hose a little, so that you could run over to the car to wash it? Well, there's a little water that will still dribble out, but not enough. It's the same with the tree. Pretty soon you've cut off so much of that xylem tissue. There's hardly any left for water to get through. But a little bit does manage to dribble through until it doesn't until pretty soon. And you know what the symptoms are then and what the signs are. It looks like you don't get fertilizer. Well where does nutrients come from? It doesn't come from you putting it on the plant that's not going to help. It comes from the root system. It comes from the ground. And then where does the food come from? Well it comes from the top of the tree from photosynthesis from the leaves making its own food. And pretty soon this food's being made and it comes down and it can't get into the root system at all. And then so the roots start starving, or the water and the nutrients the minerals that are in the ground can't move up the tree. Pretty soon the leaves look like you're not putting on enough nutrients. And that's why people think oh, I need to fertilize it. And in fact, this fellow had fertilized his tree, he put on extra water and it seemed like the tree just died even faster. But it was just this embedded tree tie that had been in there for years. But just never noticed it.
Farmer Fred 19:43
By the way, folks, if you're listening, Pam isn't angry. She's just enthusiastic.
Pam Bone 19:48
Oh yes, no, I'm not angry at all. It's just amazing to see when you go out into the landscape and you really start looking at this, how much damage we do to trees through Improper staking, especially tree ties. And it's just amazing. I see it year after year after year, called out on lots of calls, go out to commercial installations, I see so many big parking lots where trees are in parking lots and everything that can go wrong with the tree in a parking lot. And that's usually where it happens. But tree ties are put on when the landscape company first comes in. And they're directed that they have to put all these trees into a particular project. And then nobody really watches them. Or they watch them, but not very carefully. And 10 years later, the tree ties or the stakes, I've seen the stakes literally look like they're grafted to the tree. They're growing into the tree so much. So yes, I'm very passionate about improper staking and tree ties and all the things that we abuse the trees with, and it all boils down to knowing what's going on inside that tree. That's why it goes back to why we had to learn a little bit about woody plant anatomy.
Farmer Fred 21:00
And for the same reason to when you damage a tree by hitting it with a weed whacker or running into it with a lawnmower or again, having an impulse sprinkler hitting that tree directly, you'll see a discolored area from where a sprinkler has been hitting it, the same types of injuries are occurring.
Pam Bone 21:18
Exactly. In fact, the impact sprinklers are real good one, you don't know what's going on, because you can't see it. But think of this transport system. Think of them as like straws inside, little tubes inside the tree. So what happens when the impact sprinkler hits it, it goes bam, bam, bam against the trunk. And what it's doing is just like trying to drink through a crushed straw. And you know, a lot of those paper straws, they fall apart really fast nowadays. That's why people like the plastic straws. But now of course for environmental reasons, we're going to the paper straws. Well, the paper straws collapse. Same thing happens when you're hitting a tree. Bam, bam, bam with the impact sprinkler or you're letting ivy grow up around a tree and it starts to squeeze the trunk or a tree tie starts to squeeze it. First thing it does, it crushes the tissue underneath. And that tissue is transporting things and it can't transport through a crushed straw. And that's what's happening there. If you hit the tree with a weed whacker, what you're doing, then, you're just taking off all of the flow on cambium and xylem. It's gone. You've just removed it or you've cut through it and severed the lifeline of the tree right there. And so that's what the problems are that's going on, you're really impacting what's supposed to be going on inside the tree and what's supposed to be keeping the tree living and transporting and healthy. And now you've just unfortunately taken that away the tree's ability. And that's where you have to kind of decide sometimes has it girdled all the way around, has it circled it? Did you weed whack just part of it? Was the injury to the trunk from some animal chewing on it, or a car hitting it or something? And enough that the tree can then close over the wound enough? Is there still enough phloem, cambium and xylem left to support the tree? These are all questions that you kind of have to answer.
Farmer Fred 23:20
Or you can always call in a consulting arborist to do a professional diagnosis if you're treating. That's not a bad idea. If you have grown trees on your property, every few years or so, spend the money on a consulting arborist to come in and give you a health check on your trees.
Pam Bone 23:38
Yes, look for either a consulting arborist or a certified arborist. They're certified through the International Society of arboriculture, the ISA. And these are people that have met certain standards, they carry workman's comp insurance. They've taken an extensive test. They understand what's really going on and they understand the scientific principles behind tree care. So I always ask that people look for a certified arborist. The other thing is, if you just have a question about trees and how they're growing and different things, talk to your Master Gardener in your at your local Cooperative Extension. They can often answer. And then many states have nursery personnel that also may have a knowledge of trees too. So you can talk to a nursery professional.
Farmer Fred 24:22
We've only scratched the surface, so to speak, on trees and their problems. And I'm sure we'll be talking more with Pam Bone in the future about the trees in your yard. Pam Bone, Urban Forester, Master Gardener, tree expert. Thanks so much for all the information.
Pam Bone 24:39
Well thank you very much for having me, Fred. I'm very passionate about trees and I'd be happy to come back and give even more information about how to keep your trees healthy, safe and happy.
Mary in VA 24:55
Hi, Farmer Fred, this is Mary. I garden in Arlington, Virginia. Which is zone 7A, I'm a new gardener, I started gardening during the pandemic, we recently had a tropical storm blow through and it knocked one of my dahlias completely off. It severed the plant from its tuber. And so I was wondering what should I do with the tuber? Do you think I can get another plant out of it this season?
Farmer Fred 25:22
Mary, good question about the Dahlia. Will it come back? Well, most of the Dahlia experts I talked to said leave it alone, it will probably resprout. But there's another way you can propagate that plant if you have any stem left. And that's to take some stem cuttings from the dahlia, but you're going to need about three to four inches worth. And you want to make sure to make the cut above the lowest node, that'll help leave a bud on the tuber for regrowth of that tuber, because that's what you're trying to save primarily. Nodes, by the way, are the points on a stem where the bud,s leaves and branching twigs originate. Sometimes they're bumps, sometimes they look like little zits, but the nodes are very important. They're a crucial spot on a plant. So take that three to four inch cutting. And again, saving at least one bud on the tuber. Take that cutting, trim the base of that cutting to just below a node, and remove all but the top two leaves and take care of to preserve the dormant buds or eyes that you're going to see along that stem. Insert the cuttings into containers that contain a soilless mix, like a seed starting mix. You can put them in peat pots or just small, three-inch containers and an easy draining medium. You want to keep those cuttings at a minimum of 61 degrees at night and they should root in two to three weeks when their roots are well developed. You can pot the cuttings; or ,if weather permits, plant them out in their final positions. And that advice is from an excellent book I have and you should have, too, called Plant Propagation by the American Horticultural Society. (Newer editions are named: "Propagating Plants: How to Create New Plants for Free".) Excellent advice for getting more plants out of your existing plants for just about every plant grown in the United States. Again, it's by the American Horticultural Society called plant propagation (Newer editions are named: "Propagating Plants: How to Create New Plants for Free".) Thanks for the question Mary. And because Mary submitted an audio question and we used it on the air and we did it during the month of July, Mary is getting, courtesy of the great folks at Smart Pots, a free Smart Pot, their six foot long raised bed fabric planter. 16 inches wide, 16 inches tall, six feet long with partitions built in. It holds over 10 and a half cubic feet of soil. Again, you can call us with your garden question at 916-292-8964 or go to speakpipe.com slash gardenbasics, and that's one word, gardenbasics, and record your question online. It's easy, and it's good audio quality too. I like that. And by the way, in your message, be sure to tell us where you live so we can better answer your garden question and thanks for giving us a call. We'd like to hear your voice.
Farmer Fred 28:01
Garden Basics comes out every Tuesday and Friday. It's brought to you by Smart Pots. Garden Basics is available wherever podcasts are handed out. And that includes Apple, Iheart, Stitcher, Spotify, Overcast, Google, Podcast Addict, Cast Box, and Pocket Casts. Thank you for listening, subscribing and leaving comments. We appreciate it.
