With warmer temperatures and water restrictions - how do you keep your lawn green?
August 14, 2012 1:12 p.m.
Nan Sterman, gardening expert, Plant Soup, Inc.
Related Story: Live Chat: Hot Weather And Lawn Care
CAVANAUGH: If there's anything that hates weather, it's your front lawn. Many San Diego lawns weren't doing too well before this heat wave. Now it seems brown is the new green. Considering the overriding need for conservation, and our warming climate, other days of lush green laws over in San Diego? My guest, Nan Sterman, will say yes, and not a moment too soon. But she's also here to talk about alternatives that are better for the environment and easy on the eyes. Nan Sterman is a garden designer and author of California gardener's guide, volume 2, and water wise plants for the southwest.
STERMAN: Thank you, Maureen. I'm so happy to be here.
CAVANAUGH: Nan will be answering all your gardening questions in a live chat that's going to start right after the show at 1:00 right here on KPBS.org. That's of course our website. But we have the pleasure of speaking with her a little bit before about lawns at least. What is the issue with lawns Nan?
STERMAN: Well, you kind of -- you started it off by talking about water. Lawns are really thirsty plants. There's really almost no nonaquatic plants in our gardens that require as much water as lawns do, when you think about it. When you set your watering system, the frequency you water your lawn as compared to other plants in your garden, the water goes on the lawn much more often. But it's not just water that's an issue. If you look at this whole issue of sustainability, lawns for our region are pretty much at the bottom of the heap. There's nothing that needs to be pruned as often. Mowing a lawn pruning it. Nothing requires fertilizer as often. Nothing requires power tools as often. And when you have power tools and you're using fossil fuels, you're creating greenhouse gases. And most people rather than leaving the lawn clippings on their lawn, most people put the clippings in the green waste which is better than throwing it away. But even in the green waste, you have big trucks that run on fossil fuels that pick it up and take it to be processed, and then we go get it in our cars to use as mulch, and mulch is good, but if you just left it on your lawn, it would be even better. So there's a whole host of reasons to look for something other than lawn.
CAVANAUGH: As far as you're concerned, it's an entire sort of bad ecological circle.
STERMAN: Yes. That's a way, way to describe it.
CAVANAUGH: Let's turn our gaze to some of the lawns that you see in San Diego right now. Is the fact that we have water restrictions, you know, in the sense that there is a time when we are supposed to water and a time when we are not, is that the culprit behind the really bad looking lawns we're see something
STERMAN: I wouldn't say so. The water restrictions right now, the only agency that has restrictions right now is the City of San Diego. And their restrictions are not on the amount of water. They're on when during the day you can water. And their restrictions make perfect sense. They want you to water early in the day. And if you do that, then your grass or plants, the leaves have time to dry off before evening. When you have trouble is when you have wet leaves overnight. That's when fungus and bacteria set in on the plants. So your lawn should do better under the watering limitations.
CAVANAUGH: So why are the lawns sort of drying out and burning up? Is it the kind of heat we're having or is it because this is just a bad place for lawns to begin with?
STERMAN: Well, I'd say it's the latter. And as people become more aware of what it's costing them to put water on their lawns, especially when money is tight, and you have to make a decision, that's one of the places where people are starting to cut back. In addition to that, a lot of people are really recognizing how problematic lawns are. And almost all the designs I've done in the last two years have been with a very, very limited amount of lawn. I get calls constantly from people saying I need to get rid of my grass. Help me.
CAVANAUGH: You have talked a lot about on this program with drip irrigation. Is that an alternative?
STERMAN: It can be used with a lawn. You have to either plow through it, and the drop the lines, and then cover over it. That's a lot of work.
CAVANAUGH: We seem to use an awful lot of our water toward maintaining landscaping and lawns in San Diego. How much of that do we use?
STERMAN: Well, this is the pie in the sky question. The county of San Diego estimates that 30% of the water used in a residential basis is used on lawns. I've seen it as high as 50% of our outdoor -- sorry, our water use is used outdoor on landscape.
CAVANAUGH: There's a particular type of grass that makes up the usual lawn.
STERMAN: A couple of different.
CAVANAUGH: Are there low-water lawns if you used another type of grass?
STERMAN: There are true grasses that take less water than the typical lawn grasses. They're still not as low as low-water plants are. What are you trying to accomplish? What's your goal? Do you really need a sea of green? If you need a sea of green that you're just going to look at, there are many, many different options for plants. And in fact you could plant a whole garden, in place of your lawn and use a fraction of the water you're using now. If you need a play space for children, I have to perspectives on that. One is I've gotten to the point now where I perceive lawn, which I think has its uses, very much the same way I perceive swimming pools. It's nice to have one in everybody's backyard. But the truth is we don't use them enough to justify that. And where a lawn belongs is more in a community environment where many, many people can take advantage of the same resource.
CAVANAUGH: Like Balboa Park.
STERMAN: Sure, or your neighborhood park. A place where everybody ins neighborhood can gather and use the lawn. If you have really tiny children who aren't old enough to go to the park, okay. Okay. But how much space is a little tiny child going to need? 100 square feet maybe? Not much. So it's really, what are you trying to accomplish? And if you have that small a size, then there's some low-water true grasses. None of them make that nice cushy lawn that we think of as lawn. There are other plants that look like grass, like the sedges, meadow sedges, which is a native, and California do you know sedge. I've talked about them before. They're virtually indistinguishable to most people. And you can plant them and grow them as a kind of sea of green that you can walk through, and you can leave them tufted and wild looking or naturalistic looking, that's the better term. They're 6 or 8 inches tall, or you can mow them, and they look like a lawn. But you don't have to mow them except a couple timeless a year.
CAVANAUGH: Is this the kind of lawn that you can sit in and play on?
STERMAN: I guess it depends on what your expectation is. If you're looking for a play surface, not really. If you want to sit on it, and you mow it, yeah, you can do that. You're not going to sit on it and sink into it and go ah. You just won't. But I have a meadow, I planted a meadow of these plant, and it's the negative space in my garden. Since my garden is pretty chaotic, it's nice to have some negative space. But I don't water it except maybe once a week. Overhead spray. It's the only overhead spray in my entire garden.
CAVANAUGH: You have spoken about low-water grasses that are sold in other regions of the country as low-water alternatives but that aren't really low-water when it comes to being planted here in San Diego. Why is that?
STERMAN: Okay. So when we talk about low-water, we're talking about a couple of things. We're talking about the water we have to add beyond what mother nature provides, right? What's our rainfall? 10 or 11 inches? So we're looking at how much water we have to put on. And we're looking at how drought-tolerant, or how little water those plants can survive on. One of the determinants is how deep the roots go. So a lot of the grasses that we already use, their roots will go five, 6 feet deep. The low-water grasses that you're talking about, they go down maybe 12 inches. But they get what they need from the sky. We don't have that. So we have to add more water. If a grass that's 6 feet deep is not really tolerant here, how could a grass whose roots are 6 feet deep be drought tolerant?
CAVANAUGH: I just want to mention easy turf. The cemetery at fort Rosecranz put in easy turf. You don't water it. What's your feeling on artificial turf?
STERMAN: Did you see my shiver?
[ LAUGHTER ]
STERMAN: Let's go back to expectations. Artificial turf is not living. It's a petroleum product. It's outdoor carpet. What situations do you need outdoor carpet in? You can't look at it as an alternative to grass. You look at it as an outdoor carpet. It's not a sustainable product at all, in any way shape or form. And it doesn't even give us the few advantages that grass gives us, which is cooling the environment, not a lot, but some. And sequestering carbon. So artificial turf is made of petroleum product. Installation, especially in a play area, involves mixing sand with ground up recycled rubber tires. So you lay that down underneath on top of the dirt, then you put on the artificial turf, and over time, it rains, water goes through, etc. So that rubber leaches into the soil below, and the next person doesn't want it, how do you get rid of it? Anything grown in its place we don't know. But it seems unlikely just knowing how plants work. So we have this contamination issue. Then we have an issue of recycleability. I was looking at the easy turf website to figure out what the longevity of their product is. They estimate 20 or 30 years. But their warrant is eight years. So let's say eight year, you get holes, the color fades, whatever. So what are you going to do with it? Some claims to be recycleable. I talked to Steven Greeley, where could I recycle this? He says nobody takes it in San Diego. So what does that do for our landfills?
CAVANAUGH: Well, okay.
STERMAN: Am I ranting? I don't mean to. I'm just laying it out.
CAVANAUGH: What, therefore, I guess you're talking about we need to reimagine this space.
STERMAN: We do. That's exactly right.
STERMAN: Well, I think one of the big barriers is that people are a little bit afraid because they don't really know what to do. Well, I like to think that people are smart and that with a little bit of encouragement and hand-holding and research, they can figure it out. They can hire somebody to help them figure it out. There are places to go around town to understand what you can do instead of turf. The water conservation garden at Cuyamaca college is the first place to did to get ideas. Is San Diego botanic garden has some wonderful exhibits as well that show you how beautiful you can create a garden using plants that are low-water. Everything is geographical. So if you look at the Mediterranean climate garden, the native garden, then you see plants that are low-water. My books, the classes I teach, the classes my colleagues teach, if you start doing your research and homework, you can figure it out.
CAVANAUGH: You've opened up so many questions here that Nan Sterman will be answering your gardening questions on any topic, anything about gardening, during a live chat that gets underway in just about thee minutes on KPBS.org. So you're going to hurry up there, Nan, and I want to thank you so much for being with us.
STERMAN: Thank you for inviting me, Maureen. It's always a pleasure.