Orchard People

If you're growing fruit trees, you probably put some thought into what to feed them. Well nourished trees are healthier, and they also direct lots of those nutrients into the growing fruit. That's why correctly fertilized fruit trees produce a better quality harvest. But what about irrigation? Some growers don't think much about it and they only water their fruit trees when the trees look stressed.
Others may water too frequently, hoping to ensure that the fruit tree's roots never dry out. But here's the problem. If your tree gets too little water, it can become dehydrated and weak. And if your tree gets too much water, well, it can get root rot and fungal diseases. So the question is, how do you get it right?
So irrigation is the topic of today's show. And my guest today is Robert Couric, author of Roots Demystified, Changing Your Gardening Habits to Help Roots Thrive. And Robert has also written several other books, including Greater Garden Yields with Drip Irrigation and Sustainable Food Gardens. Now, before we dig in, I would love to hear from you.
How do you irrigate your fruit trees? What are your questions about irrigation? Email us during the live show with a question, a comment, or even just to say hi, and we'll enter you into today's listener contest. The prize is PDF copies of several of Robert's books, including Roots Demystified and Greater Garden Yields with Drip Irrigation.
And the total value of these PDFs is 20. So to enter the contest, just send your email to instudio101 at gmail. com. That's instudio101 at gmail. com. And remember to include your first name and where you're writing from. We look forward to hearing from you. So. Now let's dig into today's topic and here with me I have Robert.
Welcome to the show. Hi Susan. So lovely to have you here today and I know you are a person who has thought deeply about irrigation. Why is it that it's, when did it start to become very important to you as a gardener?
Well, I started gardening in 74, uh, and, uh, sure enough, come 75, the drought began and so there were no drip systems in 75, but I hobbled together a system that used less water, uh, using some off the shelf hardware from the greenhouse industry, um, but it was, uh, Oh, and quite a few years before you could buy drip irrigation hardware as we're used to it now.
So you were sort of an early tinkerer in figuring out how to get your plants hydrated. And let's clarify, you live in California. Um, so it's a pretty hot Dry climate,
right? Yes, it used to be, uh, April through April, maybe rains and then start up again in September, October. Now it's more like no rains after March, uh, and it stays dry into November.
Um, so we have. Dry season. So in the 75, I was putting in gray water systems as well as the low volume, so called drip systems. Uh, and none of my clients had ever mulched their garden. It was considered tacky, um, so I started mulching my, their gardens and, uh, they noticed that the weeds were down, so everybody went mulch then.
Interesting. Wow. So you were a pioneer in various ways because we know mulch helps to keep the moisture in the soil. Yep. And gray water is fantastic. If you're getting, you know, rainwater or water that's been used for some other purpose that can be, uh, used in a garden, that's great. Thanks. Now, again, coming from California, you live in a dry climate, do you think, and I know your garden books are for everybody.
If, if for those of us who don't live in a dry climate, can we just let our fruit trees do what they do and not worry about irrigation?
You can, it depends upon the frequency of the... Rain and how much you want to improve growth and yields. Uh, what I say, there's isn't a lot of data on it, but I would say if you're going periodically with a four week drought, no rain whatsoever, then drip turned on during that period will just keep things hustling along and looking great.
And so you would maintain consistent. Um, but if it's less than four weeks, like in Missouri, a drought was two weeks, uh, where I grew up. And, um, So then, you know, you can pretty much ignore drip irrigation for trees because they, if you've done it right, they have an extensive root system and they can gather the moisture themselves.
Gotcha. Now, another one of your books is called Greater Garden Yields with Drip Irrigation. Now, is there scientific evidence that actually suggests that by Watering your trees and plants correctly, you can actually get better harvests.
Yes. The book focuses on vegetables because, uh, there's a bigger market, so to speak, for vegetable growers.
But it does apply to fruit trees. But basically, I have dozens of studies done by universities in the... In the book that show that starting out with a drip, you can at least get 20% greater yields overall. There was a woman in India doing chilies and she used 38% less water but got 48% more chilies.
Interesting. So it sounds like this is something that hopefully over the years, more and more research will be done on it, especially with fruit trees. Um, we have an email here from Bob. Another Bob. Um, Hello, Susan and Robert. Happy New Year. All right. The first and most important question for you is the premise of irrigation for fruit trees.
How much? Thanks. Oh, I'm listening from Hoboken, New Jersey. So Bob wants a concrete. Tell us how much to water our fruit trees. How much water do they need? Is there an answer to that question?
Enough and not too much. Basically, people say, Oh, I want to add five gallons a week. Well, that in our area, that's what a lot of people do when they plant a bare root tree, but there's a thing called evapotranspiration rate, and that measures the losses of moisture from evaporation of the soil and transpiration of the foliage, and it's weather dependent.
And once you have the ET rate, evapotranspiration rate, you'll know exactly how many gallons of water are lost. And you can then replace it on a daily basis if you want to keep things just moving along very nicely. So like where I live, come June, it's based what's called inches per month. Uh, in June, basically, my garden needs, uh, 14 gallons of water per 100 square feet.
So that, in many cases, that means you're leaving the drip system on for as much as 15 minutes on a daily base to keep the losses replaced. So usually that's, uh, a lot more than what people are doing.
So when you talk about this, you know, this rate of evaporation, transpiration, people are going to be very stressed.
It's like, how do I know what my soil is retaining? Um, is this, and I noticed in one of your books, you have a way of calculating this is, can this be calculated by anybody or is it more inviting an expert in to check your soil?
Oh, well, it helps to know what soil is like, so he can figure out where to put.
But as far as the ET rate, evapotranspiration, if you do a Google search for your town, state, evapotranspiration rate, you can find, if you're careful looking through, you can find it. So I did one for Seattle, because I'm going to be talking there, and I found it for every month for about 30 cities throughout the state.
Washington State. What you do is you go to the local, uh, maybe go to the master gardeners, maybe go to the fire department. Maybe it's really hard to find initially, but the master gardeners should have it. What I say is that if your master gardener can't tell you what the E. T. rate is, fire them. They don't, they don't deserve to be doing what they're doing.
Uh, good advice. Okay, we have an email now from Charlie. Charlie says, Hi, no questions here right now, but please enter me into the contest today. I live in Thompson, Manitoba. Happy New Year. Okay, so let's talk about Where that water goes. Let's talk about root roots and one of the things that I really was impressed with about you when I first learned about you is that you have written entire books on roots because roots are the central part of the plant.
The most important place because they take in the water and nutrients. So can you tell us a little bit about the role of roots and how they differ from tree to tree and from plant to plant?
Well, basically, roots grow much further from the trunk on a tree than most people realize. In a heavy soil, they might grow half again further than the drip line of the tree, the foliage.
In a sandy soil, three, five, six, seven times wider than the drip line of the tree. So where are people putting their... Their mulch and their water next to the trunk and that's the worst place to put it as a tree matures and it confines. I call it water bondage. If you just keep watering, fertilizing a foot away from the trunk, roots will stay there and they won't explore a large volume of soil.
To deal with, uh, periodic droughts and that sort of thing.
That's so, you know, spot on because I get wound up. I, I know that a lot of arborists when they walk around and they see how people have mulched their trees. And there's this little tiny circle just around the trunk and then they plant their hostas or, you know, whatever.
And you get so wound up you want to tell them off and say, listen, think about the tree. It's got these roots, they're trying to reach out, they need to stabilize the tree, they need to find food. That's it. So I do get a little wound up about that if in case you've noticed, um, but okay. So let's talk about different types of fruit trees.
Now I know you have some illustrations, uh, of tree roots that you put in your book. So let's talk first about plum trees. What might a plum tree's roots look like?
Well, there was a study done in Hungary. There's this guy, all he did was study roots of fruit trees his entire life. And he has a book out, extremely rare, but I have a copy of it.
And, um, he studied all kinds of fruit trees. And plum trees had something like 80% or more of their root system in the top three feet. And proportionally more in the top foot than the... second foot or third foot. There were occasional roots, they call them sinker roots, that went straight down from the horizontal roots, uh, two, three, four feet, but a huge percentage of the root system is shallow and horizontal and wide.
They call them
laterals. Okay, so there's our plum tree. Now, how might an apple tree look different, at least according to what he's discovered?
Well, it depends upon the soil and the rootstock, but basically they're quite similar. The guidelines for depth and width pretty much apply to most fruit trees.
The difference being that some trees have tap roots that help stabilize the tree. And give it a little bit extra advantage to water nutrients, but less than 5% of all trees have a taproot. So it's a common myth when people draw a tree, they draw a circle for the tree, they draw a circle for the roots, and then they put a taproot straight down.
Well, that's not the case. Mostly it's nut trees. Oak trees and pine trees that can have tap roots. So something like a huge redwood tree in California doesn't have a tap root. They might have roots down to 15 feet, but they're, they're horizontal mostly. And as they get further out, they get more shallow.
Incredible. So when you talk about rootstocks, I find that very interesting. So if an apple tree is on a dwarfing rootstock, I'm assuming that those roots won't stretch out far and wide. Is that
true? Well, they stretch out further than a lot of people think. Um, basically only the guy in Hungary did the research on this, uh, and he found that dwarfing roots stops tend to have less roots beyond the foliage, but not a whole lot less, but enough to make a difference.
Um, so if you wanna be on the safe side, you would water at the drip line. Of most trees and then on dwarf trees, not go any further on a standard rootstock. You could go further
now that brings it all together. So why are we going on about roots? Why is it so important? Because we need to know where to water now.
You're talking about watering at the edge of the canopy, wouldn't we want to sprinkle the water, you know, equally from the trunk out to the edge? Why would you focus on the edge of the canopy under the furthest where the furthest furthest branches are?
Well, because that's where the new roots are, and they have the root hairs, and only root hairs are absorbing the water and nutrients.
So if you did, like when I used to dig up trees as a landscaper, uh, because it had to be removed, uh, the first two, five, six, eight feet was bark on a mature tree because it's been there long enough that the roots outside the. The canopy are gathering the water and nutrients. And so if you don't, if you have bark on a root stock, you don't have root hairs.
So, um, it's important to keep that water further and further out as the tree grows.
And you also talk about when you look at these illustrations, for instance, there's also an illustration of a walnut tree and you see how deep these reeds go. How deep does the water need to go when we are irrigating our trees?
Well, that's interesting that most fruit trees have a tremendous amount of their roots in the top foot, uh, and most of the root system in the top two feet, maybe three. So if you're watering deeper than two feet, you're wasting water. Um, and if, basically, if you want to keep things happy, keep the top foot a little bit moist.
We're not talking about wet. It means that you can't hardly see the difference between dry and wet. So they're dry and moist because of the color change, but we're talking about keeping it a little bit moist, so there's not the stress of going through a really dry area, time, and then a really wet time, and then a really dry time.
So if drip irrigation kind of equals, levels that out, so the moist and dry times are not too extreme and the roots grow better.
And how do we know that we're getting down deep enough, like, you know, in our community orchards, sometimes we'll water a tree, it's a drought, it's really dry, and we'll water, and you, you feel the top bit of soil, it feels damp, it looks okay.
How do you know that that water has gone down a foot or more?
You need to dig a trench. Uh, various... It's considerably on the soil type, so at least the first time prior to planting a tree, you should dig a small trench and go down one to two feet and, and then put a drip irrigation emitter next to the trench and see how wide the wet spot gets down below, because the wet spot on the surface of drip might be, say, uh, Six inches wide and down a foot.
It's 12, 18 inches wide. So what's misleading to people is they see a wet spot on the surface with dry and then another wet spot. The roots down a foot below are sharing all that moisture. The moisture is continuous so that You ignore what's going on the surface in the sense that you want the emitters to be spaced so that the root system down a foot or so gets continuous moisture.
So on a sandy soil, that might be the rows or emitters might be every 6 inches on a clay soil might be 24, even 36 inches.
Now we're talking about if people have actually um, emitter systems and irrigation systems like that. And we will in the second half of the show describe your systems that you put in and you enjoy using.
But what if somebody is watering with a hose? Or buckets. Do you, you know, you're dumping a bucket or, you know, under the edge of the canopy somewhere. How do you know that that's getting in?
Well, that's not a problem. Usually, uh, well, oftentimes it'll be more water unless you distribute it evenly. So, like, It's not a bad idea if you have, uh, buckets of water to do a moat where you have a ring around the tree that's maybe six inches deeper than the soil around it so that you can fill that and it'll kind of make a wet moat and then it'll just It'll sink in, uh, when I start growing trees and when I lived out in the rural part of our county, I used what gray water for the first two years and I use a type of sprinkler that made lots of big droplets and no mist and um, and I did it for one to three years and then I Pull the water away and used it for other trees by having the trees, what they call dry farm, not irrigated anymore.
The growth was slower. The growth was less than the yields were slower, but I had plenty of apples. In other words, if you come home from work and you've got 50 pounds of apple line on the ground, you're either going to be very busy canning or you're going to be very guilty. Because you didn't can, so that's why dwarf fruit trees and multiple grafted trees are important so that you don't always have to fixate on maximum growth for fruit on a fruit tree.
So I have um, a question from Candice. Um, Candice on my website, orchard people. com slash questions. People can do a little video and ask me a question, which I will sometimes turn into a video and answer, or I'll give them an answer in some way, shape, or form. So Gary in the studio, let's play this clip of Candice with her fabulous question for Robert.
Hello, Susan. My name is
Candice and I'm in zone. 8B, 9A, and I have lots of fruit trees, I have figs, and I have peaches and apples, and I want to know how much I should water them, and when to water them in the winter, because we have a bipolar kind of winter, like, some days it's really cold, and then we'll get days like today, where it's 80 degrees, but then 50 at night, and in terms of my citrus, I don't know what
to do
with those, um, because we're having a good day sometimes, and we're not other times, so
please let me know.
Yeah, good question. So watering during the winter, fluctuating temperatures. What's your feedback for Candace?
Well, most trees when they're deciduous, um, are in a kind of a little bit of a suspended animation. They will have roots absorbing water and nutrients, but it's very small percentage compared to the growing season.
So I wouldn't worry about it unless you get a dry spot of a month. uh, in December and dig down then your little trench and see how deep you have to go before you see moisture. Now, when I traveled in Greece, I saw fig trees growing up. It looked like 100% rock and, and being in Greece, uh, it was very similar Mediterranean climate.
Uh, they never got water except the winter rains. Um, so I wouldn't. Something like a fig tree, as long as the root system is fairly extensive. What you would be a little bit concerned about are the evergreens like citrus. So like, uh, in the winter time here, I have citrus near the house and the Eve keeps the rain off of a lot.
So I water by hand on a weekly basis so that I can keep it consistently moist. Um, If it's in the ground, uh, you wouldn't have to water that often. Uh, if you get a decent amount of rain, let's say 12 inches or more a season, you probably could just get away with, uh, very deep mulch, well, 4 inches of mulch.
Uh, anything beyond 4 inches is usually a waste of material compared to the benefit that it provides. Um, so I would say mulch your trees, use a dense mulch. Not hay or straw, rather, um, unless you put the straw on a foot and a half deep and then it settles down to four inches. Um, but anyway, so that I wouldn't worry so much about the winter, um.
Things are growing underground in the winter, but it's a very small amount of growth.
Gotcha. Great, great answer. We've got an email from Helen. Thank you for writing, Helen. She writes, Hello from Timmins, Ontario. Like most of your listeners, you are asking the questions that we have for you. Thanks for the information.
Happy New Year to all of you. Thank you, Helen. Yes, I was wondering why the listeners are very quiet today. I guess I'm giving Robert a good grilling, so you guys aren't too concerned. Okay. Well, I'll tell you what let's actually I want to before we go, we're going to have a few words from our sponsors, but I just wanted to read on Facebook.
There was a lot of chatter when I post the question about how much do you water your fruit trees. So here's just a few little comments, uh, Carl, this is amongst a group of people who grow lots of fruit trees. Carl says, once my trees get established, I do not water. I might reconsider if we got a drought.
Jill writes, uh, she has two sites, one in Maine and one in Massachusetts. She says one has sandy soil and one has clay soil, so as we know, you know, there's different retention, water retention in each of those. Here's what Jill writes. From an East Coast point of view, we water with five gallons at planting and rarely after this.
If we have a deep drought, we water once a week with five gallons of water, slowly and deeply, so the roots go deep. We only use water hungry, dwarfing rootstocks in naturally wet areas. Mulching is the solution to watering forests. And then I'm going to read one more and we can discuss all of them. Uh, so Roberta from Manitoba says, I have heavy clay soil.
It's usually fairly humid in the summers, but in the last few years we have been experiencing a record setting drought not seen since the 1920s. So, we mulch. And she says, I grow full size rootstocks and only water if we don't get an inch or two of water for two weeks or more. So what I liked about some of those comments is it brings home this idea that different rootstocks, if it's a full size tree with a full size rootstock, it might be able to get more moisture out of the existing soil than maybe a smaller dwarf fruit tree.
What do you think about that, Robert?
Yes, it's possible because the standard for two of the massive root system has a whole lot more root hairs and in the soil so that it's exploring a cubic volume of soil that's considerably greater than the dwarf tree. Um, but you have to get very dwarf to be concerned, usually like a M9, M27, um, but come M101 or M106.
On an apple, it's not so critical, uh, the root system is massive enough to do a lot of, uh, dry farming in the sense that if you get periodic rains, you never water and let the rains take care of it. In my area, like I say, I can, in a good soil, I can go without watering fruit trees if I get them established for a year or two.
But like I say, the growth is, is less, the roots are not as massive and your yields will go down, but. As I say, that doesn't matter a lot of times, but you got plenty of fruit.
Gotcha. Okay. And one more comment here. This is Brian from Finger Lakes region of New York. He's zoned 6B. He says, I'm a small scale urban gardener.
I have silty sand soil. Deep mulch will hold in moisture, but I added drip irrigation a couple of years ago and noticed a big improvement in growth.
Yes, and that's the advantage. The best research is done with vegetables. Like I mentioned, that woman using 38% less water, but 48% more chilies. The same thing can happen with fruit trees, but there's less data on the subject.
But it's, it's been done with almonds out here in California, and it's been done with, uh, pomegranates and, and citrus. And you'll find that like vegetables, periodic. Frequent irrigation will produce the most amount of produce or fruit.
Gotcha. All right. Well, let's let's take a minute. Um, after the break, I want to talk about the best way to ensure that your fruit tree gets the water that it needs.
So we'll talk about that in the next part of the show. But first, let's take a few minutes and hear some words from our sponsors. So, Robert, you okay waiting on the line for a minute? You
bet. Yeah,
I'm here. Okay, great. You are listening to the Urban Forestry Radio Show and Podcast brought to you by the Fruit Tree Care Training website, orchardpeople.
com. This is Reality Radio 101 and I'm Susan Poizner, author of the Fruit Tree Care book, Growing Urban Orchards. And we'll be back right after the break.
And now right back to your host of the Urban Forestry Radio Show, Susan Poizner.
You are listening to the Urban Forestry Radio Show and podcast. Brought to you by the Fruit Tree Care Training website, OrchardPeople. com. This is Reality Radio 101, and I'm your host, Susan Poizner, author of the Fruit Tree Care book, Growing Urban Orchards.
In the show today, we've been talking about fruit trees and irrigation. Um, we talked about how fruit trees take in water as well as nutrients through their root systems, and we learned how correct irrigation can improve harvest quality. But now the real question is. How do you irrigate your tree correctly?
And that's what we are going to talk about next with today's guest, Robert Couric, who is the author of a wonderful book called Roots Demystified, Changing Your Gardening Habits to Improve Soil to Help Roots Thrive, and who has also written a number of other sustainable gardening books. But before we continue the show, I want to hear from you.
So send us an email right now during the live show, and ask a question or send in a comment or just say hello, and we will enter you into today's contest. And the prize is, the prize is PDF copies of a number of Robert's books, including Roots Demystified, and Greater Garden Yields with Drip Irrigation.
And the total value of these PDFs is 20. So, enter the contest right now by emailing us at instudio101 at gmail dot com, and be sure to include your first name and where you're writing from. So that's instudio101 at gmail dot com, and we look forward to hearing from you. So Robert, back to our conversation, do you have some main strategies to keep in mind when you are watering fruit trees?
Yes. Now, something, somebody earlier mentioned one or two inches of rain. Well, when you put in a drip system, the emitters that let the water out in a controlled way are measured in gallons per hour. So, what is... One inch of rain equal to gallons per hour can't be done. Nobody can do the math. So the reason we use the evapotranspiration rate and the reason we use my book is that I have the chart.
The only chart I know of the converts E. T. Right? irrigation gallons per square foot, uh, not inches of rain. So, like, in our area, come, uh, August, or July, we have what's called 10 inches per month of ET rate. That converts into over, uh, 24 inch, 24 gallons of water per hundred square feet. So, you take your garden, 100 square feet, multiply it by whatever the size of your garden is, multiply that by the number of emitters, and then you can turn, figure out how long to leave the system on, based on your gallons per hour per emitter.
Um, so, the only accurate way to really nail down the amount of water. is to the use of Apo transpiration charts. Um, and, uh, those are usually found more and more now with the master gardeners, at least in our area. Uh, the county co op, uh, extension service has the numbers as well. So it's pretty easy to, to get it where I live.
Um, but in other words, uh, I'm going to be talking in Seattle, uh, and in the summer, it never gets above seven inches per month, whereas in Santa Rosa, it'll get up to nine and a half gallons. Uh, I mean, nine and a half inches per month. So basically, uh, Seattle uses about 50% less water than where I live.
That's very interesting. Very. Is that something that you could have predicted?
No. I mean, I would know it was less because the climate is so mild compared to the drought we have down here. But I wouldn't know specifically that it's 50% unless I had the ET charts.
Um, we have a couple of emails here. One is from Gilles.
I'm not sure if I'm pronouncing your name. Please forgive me. Um, Hi Susan. Susan's greeting to you and your guest. I love this question coming up. This is a good one. I've bought these drip irrigation bags that wrap around the trunk of the tree. So those tree gator bags, you fill up the bag with water and it slowly drips into the ground.
Should I be using these bags since they are so close to the trunk? I live in Cornwall, Ontario, zone 5A, thanks. Oh my gosh, thank you for asking this question. That's
good, yeah. Those bags are... in our area used to get the tree going. In other words, one to two years at the most, uh, oftentimes just one season so that you can deal with the stress of planting a tree.
I do not recommend them beyond that because just what you said, they can cause root rot by putting the water only on the crown of the root system. So I don't use those things, uh, period. But if I were to use them, I would use them one season at the most.
Just on the baby trees, because when you even plant a bare root tree, their roots are kind of small.
You can see where the roots are when you put them in the ground. So you know you're getting the outer edge of the canopy because it's a small, tiny tree. What a great question. Thank you for asking that. We have another question here from David. Hello, this has been a great show. I'm growing apple and cherry trees, espalier style against my house due to limited space.
Is there anything different I need to consider when planning my drip irrigation system? So Dave is from Med, uh, a
a research plot of, uh, 20 Asian pears planted on what's called oblique cordone, 45, the whole trees planted at 45 degrees. And I was experimenting with how much I could prune it, uh, and different styles of pruning to see what The yields would be what I did with my drip system on each side of the tree. I put a straight line of drip the whole length of the row at the drip line.
Um, I could have put more beyond the drip line, rows like a foot apart or two feet apart, but the well where I was doing this wasn't great. So I wanted to keep the water. From use of the well to a minimum, but basically I used inline emitter tubing that has emitter built in every foot and I put it at the drip line of the espalier.
Perfect. So right at the drip line. So again, you're keeping that in mind. Now he has a house behind his tree, so that's going to limit where the. Right. The roots can stretch out too. So, um, okay, let's dive in to irrigation systems. Before we go into drip irrigation, there is an option of soaker hoses. Do you have any strong feelings about soaker hoses using them on fruit trees?
I hate soaker hoses. I don't think they should be sold, but basically there's two things wrong with soaker hoses. One, you can't go very far away from the faucet until you have much less water coming out. And even with chlorinated city water, they, because the water sits in there between irrigations, it can develop, um, um, algae bloom and it starts to seal off all those microbes.
Pores on the, uh, on the tubing so that in our area, uh, micro, I mean, uh, soaker hose might be useless after three, five years. Um, but the main thing is like, if you take, uh, inline emitter tubing with an emitter, every 12 inches built into it, And roll it out from the faucet, you can go 275 feet and have exactly the same amount of water coming out at the end as the beginning.
You can't do that with soaker hose, maybe 10 feet. Um, there's a chart in the back of my drip irrigation book that shows the length of... different types of tubing and emitters, uh, from the faucet, uh, so that I don't have that in front of me, but basically it has soaker hose and it's like 10 feet, 12 feet, 15 feet with drip irrigation, it could be 100, 200, 300 feet, uh, depending on what you're using.
So you get a, what's the advantage of that is you have a whole lot less faucets or valves than if you have a soaker hose. In other words, um, If a soaker hose goes every 100 feet at max, uh, and even though it'll be less water at the end, you would have one faucet, one filter, one controller, one pressure regulator.
And, um, if you had to do that for every 100 feet, it really adds up compared to every 200 or 300 feet.
Wow, great. Okay, we got an email here from Jane. Jane says, and my feelings exactly, wow, such great information today. Does your guest have a book out? Oh, I live in Queens, NYC. Happy New Year. So just take a moment and tell us just where people will find because people listening to the show are going to want to buy your book if they don't win it in the contest.
So what, where can they go on the internet to buy your books?
My website, uh, and technically, in most cases, my books are cheaper on my website than Amazon, so you can save a lot of money by buying from me directly. Uh, so basically, I have four or five books available in paper and three or four books available as PDFs.
I've written, uh, 19 books. But a lot of them are out of print, um, because they were done so long ago, but my two roots books are still for sale. My drip irrigation book is for sale. And my newest book, uh, sustainable food gardens just came out in October and it's available through my website. Yeah. Yeah. The website is robertcorick.
com. My name with no space, but Corick is spelled K O U R. I. K. So robertcork dot com. Are you google, uh, drip irrigation in every landscape or google food? Uh, sustainable food gardens and you'll get my name.
Perfect. Okay. We got a little bit of time left. I want to talk about Drip irrigation systems, how much money will I have to pay?
And how do I set them up? I know this is just throwing a whole bunch at you now, but give us an idea of what we have to consider, uh, when you are setting up your own system.
Well, if you're going to build a system off of an existing hose bibber faucet. Um, you start with, uh, some gizmos to convert, um, hose thread from the faucet to iron pipe thread.
A lot of the hardware after that has tight little pipe threads, whereas the ho hose threads are further apart and you can't use 'em interchangeably. So you convert it from one to the other, but then the next thing you go to is a filter because. Even in city water, you want to make sure the drip system doesn't clog due to stuff in the water and, um, being, uh, like a half gallon per hour emitter, the opening is quite small, so you can't afford to have too much stuff.
Get past the beginning of the system and then after that comes what's called a pressure regulator drip systems can't take city pressure the household city water pressures anywhere from 60 to 90 pounds per square inch drip systems like to be below 45. I like to keep them at 35 or 25. PSI pounds per square inch, so that the fittings don't blow apart and the emitters don't pop out.
Um, so you put a pressure regulator, um, after the filter and then you go to the drip system. Um, there is a YouTube I did that talks about the best pressure regulator, because most of them are really cheap. Meaning lousy plastic, they crack very easy. The one that I like to use is called Syninger. And in the video, see, we drove a truck over it, and it didn't break.
So that over 110, 000 people looked at me having a truck go over this regulator and not break. Well... That's the one to buy.
Sounds good. Okay. Couple of quick questions. Uh, let's see. This one's from Karen. Karen writes water cannons. I drive by these fruit farms and see these massive water cannons spraying a field.
Does that really work? Or are these farmers just wasting precious water? Happy new year from Waterloo, Ontario.
They're wasting water. I mean, you, you lose a tremendous amount of evaporation before. It even hits the ground. Um, and they have, if you fly over a plane in Colorado, what have you, you see these big green circles and those are what she might be calling the water cannons.
They have a pivot in the middle and a long bar and it just constantly moves around the circle with a small amount of Spray water. Um, but it still loses a lot of water to evaporation and they're basically using the aquifer to supply the water for it. And so the aquifer starts going down. You get some sight and said less and less water over time.
So it's tremendously wasteful. Hmm.
An email here from, who's this from? Monica. Uh, Monica writes, happy watering, happy new year. That's all from Prince Albert, Saskatchewan. I love that. So, okay. So you set up this system. I want to talk about the placement of the emitters. Um, because a fruit tree has roots that go out in all different directions.
So if you just sort of, you know, place your drip system on one side of the fruit tree, then all the roots on the other side, won't they just die because they don't, they don't get water? What is your solution to that?
I usually do parallel. In other words, uh, you, if you have a long row of tubing, I do it on each side of the trunk near the drip line.
If it's a very big tree isolated from other trees, I do a spiral. So I start out with solid drip hose coming into within a couple feet of the trunk, then I convert it to drip irrigation hose and make a spiral that goes out to, and maybe beyond the drip line of the tree and you leave a. In cap on the hose line, so you can take that in cap off and add more hoses that bigger, uh, so, uh, like some, like a massive pine tree that can get 40, 50 feet in diameter, you need to have the ability to add more length to the tubing as the tree gets, uh, bigger
and, um, how, how do you know how.
Uh, far apart the emitters need to be, is that dependent on soil type or, or how, what is there a
standard no, no, well, uh, if you buy the pre installed emitters that are every 12 inches, um, you can use it on, on a sandy soil because they're closer together, but you can use it also on clay and run it less time.
So on sandy soil, they run longer on clay soil. Well, it's much better to dig a trench and get a sample, like a hundred foot roll of tubing, lay it out, dig a trench and see what the wet spots are and how wide they get. Because if you have a heavy duty clay soil, you can leave it on a fairly long amount of time, but it'll spread the roots of the wet spot at the roots will spread 12, 36 inches apart.
So when you buy tubing, that's every emitters built in every three feet, it's literally. What are the costs of buying tubing that's every foot? Now I buy tubing at every foot because it gives me the most flexibility for my clients, but for my own garden, I dug, I put the tubing down and ran it for an hour, dug a trench, ran it for another hour, dug a trench.
So I knew that after one hour, it got this wide after two hours, it got that wide, got a feeling for exactly how long to leave the system on continuous moisture. Six, eight, 10 inches down.
Okay. I want to clarify these trenches. So I'm imagining that the, the line is above the ground. It's on the ground and your trench is beside where you're putting your drip system.
So you're getting a sort of a slice of soil so you can see how wide. The, like maybe a triangle or something at
the top, I mean, it's more like a balloon. Yeah. And so that, uh, you can see the color change if you do it, if you've done it after a rain, you know, it's useless, but if you do it after this enough interval between rains or in our area, anytime in the summer, you'll see a color change between the drier soil and the moisture soil from the.
drip irrigation. Uh,
okay. Lovely. Um, and now I want to talk about the difference between the different types of emitters. There is something called an inline emitter and there's something called an external emitter. What's the
difference? Well, in the old days, we only have the external emitters where you Punched a hole in the tubing and you inserted a barbed fitting with the emitter sitting on top of the hose, the drip hose.
Now we have a system where the emitter is built inside the hose with an opening at the, at the hose, but the emitter itself doesn't stick out. Of the hose. The advantage is, uh, usually in our gardens, uh, people are down on their knees every spring trying to find the emitters that popped off or broke off or got stepped on and cracked off.
Um, so they're spending a few hours every spring trying to find the mistakes or broken stuff. Um, whereas inline emitter tubing, it's sturdy enough, you can walk all over it dry. wheelbarrow over it. Uh, it'll take an enormous amount of pressure and the host still stays together together, doesn't split. And then the emitter is built in so that it doesn't get the direct pressure of the wheelbarrow, let's say.
Um, and then you can have in line emitter tubing where the emitter is 12, uh, half a gallon per hour or one gallon per hour or even two gallons per hour. But that's pretty rare. Most systems, uh, I buy half a gallon hour emitters to have for my clients, which means they may have to run it less time. If you buy emitters every 24 inches, you have to run it longer.
So every 24 inches doesn't do. A good job on a sandy soil or a really light loam. Uh, you need one inch, I mean, one foot intervals to do that. Um, and what's fascinating is people say, Oh, I'm, if I buy a drip hose and I punched in all these meters, it's going to be cheaper than buying this tubing. That's new you?
Well, I did a study at my local supplier and basically. Punching in every emitter and taking all the time to do that, the cost is 20 to 30% more than buying the inline emitter tubing. And with the inline emitter tubing, all you do is roll it out, flush it, cap it, you're done. Whereas with all the others, you got to get down on your knees and punch all these holes and put all these emitters in.
It takes hours. I had a client who wanted to save money, so they had me put out the, this is back in the old days before we had inline. So I put out the rows of tubing every two feet on her slope, and they came out the next weekend and punched in all the emitters. And then they went for three weeks to physical therapy because their wrists got ruined.
As a landscaper, my wrists were up to snuff on being able to do that, but theirs weren't. So it cost them much more than if I had done it.
So finally, once you set up your system, should you be digging it into the soil? Should you be covering it with mulch or should you leave it exposed?
You can, uh, you don't dig it in the soils.
Uh, I don't know if you have gophers. We have gophers that eat the tubing if it's buried in the soil. Um, You don't need to have the effort of doing that. You put it on the soil surface and then if you don't want to see it, you mulch it, or if you want to get better use of the water, you mulch it. The tubing is rated by the manufacturer at 10 years and full sun without breaking or splitting.
If you put. A friend of mine, we had a garlic farm, uh, for 20 years and we put in the tubing and it was still intact 20 years later. And we use straw mulch and with inline emitter tubing, there were no clogged emitters.
Amazing. So is there a certain brand people should be looking for that you like?
Well, the, like for the pressure regulator, you really got to see if you can find the Sinninger, uh, pressure regulator.
Uh, as far as filters, I like the one that's called, uh, oh boy, uh, Arc, uh, Arcan, it starts with A R K. Sorry, I forgot it, but you don't. You don't, uh, you talk to your supplier because some of these things, they split apart after a few years. Um, and then you, in our area, the best mail order source in the whole country is called Dripworks.
One, one name, Dripworks. I don't know if they can ship into Canada or not. I know they don't have a office or store in Canada, but in America, that's the best source for mail order if you don't have a local supplier.
Fantastic. I got to say this has been so much fun talking to you. So that's all for today.
We have another show coming up, my goodness, next month, which is also next year. And, um, I look forward to seeing you all back again next month with another fantastic guest and Robert, thank you so much for coming on the show today.
It's been wonderful to chat. Yeah, I really enjoyed it. Thanks.
Okay. You're listening to the urban forestry radio show and we'll see you next month.