Planting Woody Plants

Transcription

1 Planting Woody Plants [Tim Kohlhauff] All right, so today we are going to do some tree planting. We are going to go through the step by step process for correctly planting a tree. Of course the first step in planting a tree is finding the right tree for the right place. This is a native in our area of eastern Washington, this is a western tamarack or a larch and we know this is native because we actually are relocating it from another part of the course, but we are going to plant it here in an effort to turn some of this grass into native area. So we know that that is the right spot for this plant, we are putting it in an area very similar to where it came from, so that's step one. Step two is that we looked at this tree and we knew that this is a good one because it s got nice healthy tissue from top to bottom. It s got a nice central leader here, which is what we want in a tree. It s got good healthy branches and needles all the way around. And when we dug it up we found that it had nice healthy roots as well, so this was an excellent choice for us to plant. With this garbage sack down here I am simulating balled and burlapped stock. This actually was grown in a tree nursery and it was dug this morning, but we are going to pretend this is balled and burlapped because that is a much more common way to get trees. All right, the first step after we have chosen the right plant and found the right stock is to dig a hole. And over here we have already dug a hole. This might be different than some of the tree planting holes you've seen in the past. The new model for planting a tree is a wide shallow hole, so what you want is a hole that is at least three times as wide as the ball of the tree. I measured that earlier and did that. This is very sandy soil, as you can see it is almost pure sand. If you had clay soil or heavily compacted soil, it's much more common, in fact it's much better for the tree to dig a hole five times bigger than the hole rather than three. But the water is going to get through it just fine, so we are going to be fine with three times as wide. We've also made it fairly shallow. You shouldn't dig a hole deeper than the root flare of the tree, and I'll show you that root flare in a minute when we take the fake burlap off, but you don't want the tree planted too low, that's kind of an epidemic of poor tree planting right now. So we are going to make sure that this is not too deep. The old model for planting trees used to be something more like a fence post hole where it was very deep and narrow and you just plugged the tree in the hole and that was it. But this way we're doing it wide and shallow; this way we have lots of soil for the roots to spread out in. So we've got our tree and we're actually going to simulate sort of a difficult planting. This root ball, like some balled and burlapped stock is kind of falling apart, that's because we used native soil. But some balled and burlapped stock will actually fall apart and rather than taking the covering off outside of the hole we are going to wait until we get inside the hole so we don't damage the roots as much. Okay, this is usually the tricky part, getting it into the hole, but we'll just muscle it in there just like this. All right, now we've got our plant in the hole and we want to take off every bit of our fake burlap or our plastic sack here and we want to make sure and cut all of the twine that is holding it together. It might be hard to see because of the color but this twine actually wraps around the trunk and if we don't cut this off as the trunk grows, it's going to girdle the tree. When I go out and look at people s trees in their landscape, it's probably once a month I find a tree that has been in the ground three or four years and still has this twine Page 1 of 6

2 around it and it's actually causing the tree to die because it's cutting off the supply of water and nutrients. So we are going to make sure and cut all of that off when we plant the tree, let me just grab my pruners, here we go. Cut the twine and then this is a plastic bag that we can pull off, but if it were burlap we would probably have to cut it off in pieces... Here we go, we want to make sure and do it without too much damage to the root ball if we can avoid it, and because we are pretending this is a burlap sack I'm going to go ahead and cut it off just like this. All right, now you can see that this is very sandy soil because we've taken it from a very sandy area. Most balled and burlapped stock actually comes in a clay root ball that holds together a little bit better than this one does. Now we re going to pull this off. Now in a situation like this when you are worried about the root ball falling apart, this one is really coming apart, the way to get burlap out of the hole is just to gently rock the tree back and forth like this and pull the burlap out. If you can't get all of it out you can leave the burlap on the very bottom because as long as the roots can grow out to the side like this without having the burlap interfere with them, then the tree is ultimately going to be healthy. In this case we want all of the plastic out, we don't want any of the plastic in the ground. So I'm just going to keep working this out. When you buy a tree from a nursery, the root ball will be less likely to fall apart as this one is, and a little easier to work with. Here we go. Okay, let's move our tree into the center. We used this pine needle mulch at one point, it doesn't need that anymore. You can see that here's some roots from the tree and they're nice and healthy, nice and light colored here. This one has been damaged, it doesn't have that, the tip of a root that has been broken off. But we have some nice healthy roots here, they're not slimy, they're not black. Sometimes you'll find a tree that has an aroma or odor with it, that's a symptom that we might have root rot. And so these roots are just the kind that we're looking for, nice and healthy looking. So as I pull some of this pine needle mulch out I'm going to spread these roots out in the hole so that we get good growth in all directions. That's going to help this tree be more stable. Now when you're planting from a nursery the root ball, if it's in a pot, is usually sort of pot bound, all of these roots come up right against the side of the pot and be circling around. It's important to not leave the tree or shrub roots like that, you want to space them out a little bit so they start growing out and away from the main trunk. That's the way that they're going to find the water they need and give stability to the plant. So when you're doing that, even if you have to cut a few of them, if the root ball is too tight you might have to cut a few of them to get the roots out, but make sure they're headed out away from the trunk. You don't want any girdling or circling roots. In balled and burlapped, it's important too, to spread the roots out that are at the edge of the root ball because most of us don't have pure clay soils in our yard, and at the edge of that balled and burlapped root ball is usually going to be pure clay. The roots don't want to naturally cross that interface between the clay and the soil you have in your yard, and so it's important to pull those roots out a little bit so they can grow right out into the new native soil. If you don't do that, the roots are prone to start circling around inside that clay root ball and that's the last thing you want. You want it to be able to grow out in all directions. So now we've got our tree in the hole and we're spreading out the roots a little bit, and it's okay to be firm with the roots. You want to try and avoid breaking them, but it's better to break a few of the smaller ones than leave them in a circle. So now we've kind of spread these out a little bit, and I think we're ready to Page 2 of 6

3 check the level of the soil to make sure we're at the right height. One of the ways I do that is just by putting a shovel across the hole just like that, and I want this to pass right at the root flare of the tree. This should be right even with the root flare of the tree and touching the ground on both sides. Right now on the side next to me it's a bit high, it s off the ground so I'm going to take some of the soil away. This is planted just a little bit too high. I'm going to move some of the soil out of the way, and I can do that because it is very easy to lift tree. With a bigger or a heavier tree you might have to rock the tree back and forth and pull soil out either with a trowel or a shovel. Let's try that again. So we've got our shovel on either side of the hole, just like that, and it looks like we're right about perfect on the level. So we've got our root flare right at ground level. That means our tree is going to establish. The roots aren't going to be too low, they're going to get enough oxygen, and this root flare won't be buried, meaning that there won't be water and soil up against it interfering with the oxygen transfer to the trunk. So we've got that, the next step is we probably want this tree to be straight. So set it in the hole and stand back and hopefully it will stand on its own, and we want to make sure the trunk is straight. Now we're on a slope. You don't want it to be perpendicular to the slope, you want it to be straight as in growing straight. So here we go. I'm going to stand back, and it looks like it's leaning back away from us just a little bit so I'm going to adjust it a little bit there like that. That's better. And we'll take a look at it from the other side, and actually before I do that, there is something else I forgot and that is to put your best side forward. We're going to be facing this direction; this is where most of the people who see this tree are going to be looking at it so we want our best looking side facing towards where the greatest number of people can see it. So I'm just going to move this around, fluff these roots back out, and I think this is a better looking side of the tree. Okay, now we ll take a look at it again, make sure the trunk looks pretty straight from here, step over on this side, and it looks like it's pretty straight from there as well. So now we can start backfilling. When you plant a tree, you don't need to put any fertilizer in the hole. In fact, putting fertilizer in the hole will sometimes cause it to grow more shoots at the expense of growing roots, and what you want most of all when you first plant a tree is for it to grow lots of roots to establish and be healthy. So you don't need to put any fertilizer in the hole, and when you backfill this hole we've created, you want to use native soil. The same kind of soil that all of these trees' roots are going to be growing in. You don't want to put peat moss or compost in there. It's natural to want to give the tree a little extra or do something nice for the tree. When you amend the soil, put that peat moss or compost in, you're actually creating another one of those soil interfaces and so when it gets to the edge of the hole, where the compost has been, the roots, instead of crossing into the unamended native soil, will tend to want to turn a little bit or have a hard time growing across that boundary. So we're just going to use the soil that's already there. Now we're backfilling the hole and I've got this hole set to just trickle a little bit of water, and we re going to fill this whole planting hole with soil but also with water. The reason the water is really important is that it's going to push the soil into some of the sir bubbles or air pockets which we might not be able to push the soil into with our hands or with shovels. So I'm just going to have this trickling on the tree while I move the soil back into this hole and then I'm going to leave it just trickling right here for a couple of hours after I'm finished planting. That way this whole area is saturated with water and I know I'm getting the whole tree as much moisture as I can. Page 3 of 6

4 So I'm just going to start shaking this back on here and then as I can I'm just going to wash that soil down in there so there aren't any air pockets. You want to have good soil and root contact with your plant. And it also gives you a chance to make mud pies like when you were a kid. I used to work for a gardener who was from England and she called this step puddling in, and she said you couldn't plant anything without puddling in, which especially in a dry area like eastern Washington is absolutely right, but it's a good idea to do it anyway. I think we've moved our tree off center a little bit, so I'm just going to step back and readjust. With the water in the hole, it shifts where the soil is and so the tree might move on its own. That's okay, just move it back. It's okay too to press down on the roots. You want to make sure it makes good contact with the bottom of the hole. We see sometimes with trees, especially in sandy soils like this, is that after a few days they actually sink a little bit because the soil has settled. So it's a good idea after you're done to come back and make sure that the tree doesn't sink, or hasn't sunk. If you're dealing with clay soil especially or an area where there is compacted soil or drainage problems, it's okay to plant the root flare a little high in the ground because that will make sure that the tree's getting enough oxygen to the soil. You don't want to plant it too high because then the roots might dry out, might get too much oxygen exchange. But we'll just keep working on this until we've got our soil in keep moving the hose around and eventually we'll have our tree planted. You don't want to pile up the soil against the tree, but it is okay to make a little ring around the root ball with the soil that will kind of direct water that falls here, either through irrigation or through rain. It will kind of push that water towards the roots. And after a tree is first planted, one of dangers, one of the things to worry about is having the tree dry out. We don't want it to dry out and so we're just going to give it some little soil rings and that will give it a little extra water. Now I'm going to let this water sink down into the soil and make sure that there aren't any big air pockets or holes that I've missed. Well, we were hoping this tree might come back, but I don't think so now. This is a tree that was planted incorrectly, actually not when it went into the ground in its final location, but when it was potted many years ago at a nursery. And what you see here, I'll show this to you, here at the bottom of the very base of the tree and here is this very large root that was probably at the edge of the pot at one point or at the edge of the root ball and it needed to be moved up to the larger size pot, but instead it was left in and so this root started growing around in a circle, which isn't the direction you want them to grow in, of course. You want them to grow out and spread outward. And so this root itself isn t the source of the problem, but we have a lot of other roots up here that were growing around the edge of the trunk and here's an example here. Roots that started to cut off the flow of water and nutrients from the root up to the trunk and from the trunk down to the roots. So these became a real problem and the tree started looking unhealthy and yellow, and eventually starting getting different diseases and insects and we had to pull it out. But all of this could have been prevented when it was planted by pulling all of these roots out, and when they were small like this it's fairly easy to pull them out like you saw us do with planting the larch. Pull these out like this and this all would have been prevented and this tree would have lived a lot longer and had a much happier life. And so this is an example of what happens when you don't do that. Page 4 of 6

5 And hopefully behind us here we'll have an example of what happens when you pull those roots out. Now we've planted the tree, it's at the right level, and we've built a little ring of soil to keep the water close to the root ball. One of the last steps I'm going to take is to put some mulch on there. Now there are a lot of different mulches commercially available. There is composted fir bark, there is compost. This is one that we have, we chip up our woody debris and we compost it for a couple of years. I think composting it is an important thing to do because it reduces the diseases that would potentially be in here. So I'm just going to pour this in here about two to four inches thick and I'm going to keep it away from the trunk of the tree. I'm actually going to make it about even with our little soil ring. The benefit of this mulching is that it helps keep the soil cooler in the summer and warmer in the winter. Got a couple of flowers in there we don't need. It also holds moisture in the soil better, which is something that we want. We want the soil to be nice and moist around the roots of the tree. So I'm just going to spread this out evenly, I'm going to have it at about the same level as that ring of soil, and that's just so it looks even. I ll spread this out like this. This also helps reduce the amount of weeds that grow in this area, and by doing that now we don't have to have the dreaded string trimmers or mowers come to close and potentially do damage to this tree. So that's mulching. What you don't want to do, and what I've seen happen sometimes, is to pile the mulch right up against the base of the tree. That's called a mulch volcano and it doesn't do the tree any good, in fact it actually harms it by holding moisture and sometimes some decomposing diseases against the trunk of the tree. So keep the mulch away, but pile it about two to four inches. Any deeper than that doesn't really help, so keep a nice even level and you can add more mulch as this breaks down, but normally you don't have to add too much more. So the last step that we're going to do in planting this tree is; we're on the golf course and so we're going to end up staking this tree. Most trees do not need to be staked, especially ones that come in a pot or are balled and burlapped. Bareroot trees sometimes do, trees that are on steep slopes will sometimes need to be, and strangely enough trees that are in high traffic areas when they are staked actually suffer less vandalism. The stakes function as some sort of a psychological barrier to vandalism. So the last thing we're going to do is put some stakes in here. We decided to stake this tree because we're in a high traffic area and we do have some wind in this area so we are going to stake it. Now the placement of the stakes - we obviously want to place it on either side of the tree, but we also want to make a line here that is perpendicular to the prevailing wind. In other words, our wind direction is coming right this way, and we are going to tie this tree kind of loosely, and here is a plastic chain. By the way, if you do stake a tree, use something like this that is not going to cut the bark. You want to use something that is a little bit dull. For heaven's sake don't use wire. So we're just going to put this around the tree, and we could cut this down to the right size, but this will work for now. Now we don't want it too tight because we want the stakes here to keep the tree from falling over, but we want the wind to push it back and forth. When it pushes it rocks it in the hole like that and it stimulates root growth in the tree. The tree essentially realizes, hey I need some stability, so it starts sending out roots to increase its stability in the hole, it knows it needs to stabilize. If this is too tight and the tree can't move at all, then it thinks it's already stable and it will put its energy into producing more needles. It's very important, if you do stake a tree, to come back Page 5 of 6

6 and remove the stakes after no more than a year. After one year all of the gentle rocking that the tree has gone through will produce all the roots it's going to and it starts to use the stake as a crutch, and it thinks that it is part of its anchoring system. So you need to come back after one year, take the stakes away, and that will stimulate the tree to grow even more stabilizing roots. The stakes will hold it in place long enough to get established and then once they are not needed anymore you do not want them to be a crutch and so we will take them away and the tree will grow much more stable and it will put on its top growth as it needs to. So that's staking and tying, we ve put mulch and we've placed it at the right level, I think all that is left is we need to bring a lawn chair out here and wait for the shade to grow. Page 6 of 6