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KPBS Midday Edition

Tips For Winter Gardening In California

Nan Sterman's garden is filled with California native plants.
Nan Sterman
Nan Sterman's garden is filled with California native plants.
Winter Gardening With California Native Plants
Nan Sterman, garden journalist and host of the KPBS show "A Growing Passion"

ALISON ST JOHN: You're listening to mid-day edition on K P B S, I'm Alison St John in for Maureen Cavanaugh. As you work around Diego's neighborhoods how many gardens are changing? In many places people are really rethinking their yards and making the shift to more drought tolerant plants. And some of the most drought tolerant plants you can choose are native plants. Plants that have grown in this region or regions with similar climates for hundreds of years. We are in that time of year when it's best to plant native species so we've invited author and gardening expert Nan Sterman in studio to tell us what to look for and how to the do it. Thanks so much for joining us, Nan. NAN STERMAN: I'm very happy to be here. Nice to see you too. ALISON ST JOHN: So first of all, why is this a good time of year to be thinking about integrating native plants into your garden? NAN STERMAN: It's a good time of year to be planting almost any plant other than summer vegetables. So the reason this is a good time of year to plant is because of the climate conditions right now -- the weather conditions right now. We're still at a point where the soil is warm. In fact our soil is warm pretty much all year around. The air has cooled down. When you transplant plants the first thing it's important for them to do is establish their roots because the roots pull the water up out of the soil, and the nutrients, but the water first. And the tricky part is to make sure that you get the plants established so the roots are pulling up water faster than or as fast as water is being lost enter the air from the leaves, so this is the whole kind of establishment period we talk about. And because the air is cool now and there is rain coming down, yeah, this is a really good time to plant. ALISON ST JOHN: So actually will that save us water on our water bills if we introduce natives into our garden, and how long might they it take us to get to that point? NAN STERMAN: Well, yes it will gave you water if you plant any drought tolerant plant including natives. So there are drought tolerant plants from our climate, from the desert, and from the other Mediterranean climates of the world, so that would be the west coast of Chile, the Mediterranean basin, the southern tip of South Africa and western and southern Australia. ALISON ST JOHN: So we'll be looking in gardening stores for plants from those areas. NAN STERMAN: Yes, exactly. Those are the plants you want to look for, the plants from those regions. Plant those in your garden, but the other thing is you have to water them according to their need rather than over watering them. Most of us love our plants to death, we may over water them. So the way you're going to save water is if you have the plants you can water with less water, that's a little confusing, and then actually doing it. ALISON ST JOHN: Watering them less. NAN STERMAN: Exactly. ALISON ST JOHN: So -- but is it true to say that right away they don't need very much water? NAN STERMAN: No that's actually not true to say. All plants need an establishment period and they all have to be kept damp. Not wet, but damp in that initial period so they get the chance to root and be healthy right away. So I have had people say to me I tried those drought tolerant plants and they didn't work, and it's like well what did you do? How did you water them? And they go water them, they're drought tolerant. Oh no, no, no, no - you have to water them until they are established and then you can cut back. ALISON ST JOHN: And that might take a year? NAN STERMAN: Depending really on the size of the plant. How big that root bulb is. A perennial or a small shrub or medium-sized shrub, yeah a year is probably plenty. A tree, you might have to do a year or two until they are established. It's really a matter of trial and error, hopefully more trial than error. And you have to pay attention you can't just put them in the ground and turn on the timer so that they water every three or six -- or whatever many days and walk away and expect that to work. That doesn't work. ALISON ST JOHN: So let's get into some specific native plants. We all think about sage, you know, chaparral. What kind of plants might actually fit nicely into a San Diego garden and not just look like chaparral. NAN STERMAN: Well, lots of (CHECK AUDIO) plants fit nicely into gardens because gardens are different from habitat. In part it's because they are cared for. We trim them, we plant them. You can have a native garden that is not habitat basically, but the plants that work well are the sages, the salvias. There is the toyons which are beautiful shrubs that have red berries in winter. In fact these are the shrubs that Hollywood is named for because when the developers were developing Hollywood when they first got there the hills were covered in toyons. ALISON ST JOHN: Not holly at all, but toyon. NAN STERMAN: Yes, which reminded them of hollies. Of course when they built all of those houses they tore all of them out, but that's another story not all of them, some of them. There are wonderful native oaks, there is sonomas pretty much universal chaparral plant. ALISON ST JOHN: Looks a bit like a lilac. NAN STERMAN: People call them lilacs, they have nothing to do with lilacs, again. ALISON ST JOHN: Maybe it's the color. NAN STERMAN: They are blue. Different shades of blue to white. Okay. If you want to call them that. But there are many wonderful lilacs some native to San Diego County and there are wonderful manzanitas which have incredibly beautiful bark. Monkey flowers, again native to San Diego County. matilija poppy which is a big huge poppy, stands five- or six-feet tall. It's a perennial. ALISON ST JOHN: They call it the fried egg plant. NAN STERMAN: Yes, absolutely those are very common ones to start. The matilija is a little tricky to get established, but those are some of the plants you find most often in the nursery and are really excellent plants for our gardens. ALISON ST JOHN: So if you're -- because you have to be careful where you plant things. Is there a certain kind of plant that might cause a problem in your garden if you put it in a wrong place? Like a matilija poppy or a sonoma. NAN STERMAN: The only problem you would have with a matilija poppy is it tends to spread pretty aggressively. So it's best for a very large garden or a slope, some place where it can be left to naturalize, but other than that, nope can't think of any problems. ALISON ST JOHN: Is it okay to go into the canyons and dig up plants that you see? NAN STERMAN: No, no and double no. Thank you for asking me that question. You never want to dig up plants out of nature. What you want to do is go to the nursery and your local independent garden center. We have lots of them still thankfully in San Diego are going to have natives you often will find natives in some of the bigger garden centers as well, but local independents are very reliable places to find natives. ALISON ST JOHN: So in fact when you go to the gardening stores they are not cheap, the natives. They are not something oh I'll just try and plant it and if it doesn't work it doesn't work; so what is your best advice as to how to make a native plant take and root and become a natural part of your garden? NAN STERMAN: Let's go back for a second. Plants aren't cheap, and if it is cheap that means you don't want to buy it because it's probably a plant that wasn't grown very well or cared for very well. ALISON ST JOHN: Thank you for making that point. NAN STERMAN: It's an investment just like anything else. That's another reason you don't want to put it in the ground and just walk away. ALISON ST JOHN: Right. NAN STERMAN: The best way to insure that your native plants will survive transplant is to use a very -- to be careful about how you actually do it. First of all when they are in that nursery can you never want them to dry out completely because it's such a small volume of soil their roots can be harmed irreparably. So you want to make sure that they stay a little bit damp, not wet, but a little bit damp then make sure the plant you choose wants to grow under the conditions you want to plant it into. Sun, shade, heavy soil like clay or well-draining soil. You want to make sure it's the right plant for the right place. Once you know you have the right plant for the right place and the other thing to make sure is you have enough room in the spot you want to put the plant for its ultimate size. You never want to put a plant in a space that's too small because you're creating a maintenance nightmare for you, and it doesn't do the plant any good. ALISON ST JOHN: And so how -- if you see something in a pot in the garden store? NAN STERMAN: Look at the label. Ask, look around your neighborhood and see how those plants grow in your neighborhood. ALISON ST JOHN: And in fact, if it's growing really big you're going to spend half of your life to trimming it down to fit the space. NAN STERMAN: And that's silly. Why do that? Why do that? ALISON ST JOHN: Extra work. NAN STERMAN: Exactly. And you're making all kinds of extra green waste that has to go to the recycling center then you've got greenhouse gases. It's just it doesn't make any sense. ALISON ST JOHN: So the right size is important to consider when picking a plant. NAN STERMAN: Absolutely and even if you're planting in front of a window you don't want a plant that's going to grow so tall that it's going to block that window you want a plant you're going to look out over and enjoy. Then where are you going to plant it. My favorite planting method is first of all to water the plant in the pot and make sure that it's wet, the roots are wet to start with. You dig your hole just about the same depth - about as deep as that nursery can is tall. ALISON ST JOHN: Okay. NAN STERMAN: If it's a one-gallon maybe eight or ten-inches tall just to look at the pot. You want to dig a little wider than the can is, but not deeper. ALISON ST JOHN: Not deeper. Why not deeper? NAN STERMAN: Because research has shown that plants don't really like it when you dig the hole deeper and you want to make sure you don't plant the plant any deeper than it was in the can. In fact with natives, you want to make sure -- an inch higher then they work. ALISON ST JOHN: Okay. NAN STERMAN: Because you want to make sure the water drains away and essentially they will settle to about the right height anyway. So you've got wet roots, you want to dig the hole. Fill the hole with water. Let the water drain out that way you make sure that the soil surrounding the plant is damp too. Then you take the plant. You take it out of the can, put it in the hole. Don't add any amendments these are native plants and then as you back fill the hole make sure you firm the soil and then water it too so that that soil settles around the root bulb. And after it's all done you give it one more little round of water and that's how you plant it. ALISON ST JOHN: You're off. But as you were saying you have to make sure the soil and there are lots of different kinds of soils in our gardens, you know, how can you tell whether your soil is going to match the soil that that plant came out over, so that it feels at home when it arrives. NAN STERMAN: Well, first of all you're going to do your homework and you're going to find out what kind of soil that plant really likes. You're going to make sure that if it requires a really good drainage you're not going to put it into really heavy adobe, that's not a good match. Some people actually wash all of the soil off of the plant roots before they put them in the ground. ALISON ST JOHN: How does that work? NAN STERMAN: Actually it works pretty well except for those matilija poppies because they do not like to have their roots disturbed. There is a whole process for doing that if anyone is interested they can e-mail me or find one of my books and I describe that. ALISON ST JOHN: We're talking with Nan Sterman here, so you can google her on the web and find that out. So that is for the matilija poppies you've got a particular strategy. NAN STERMAN: That's exactly right. And, you know doing your homework is really the most important thing. ALISON ST JOHN: Okay. So now you had mentioned oaks, and I think a lot of people would be just amazed to discover you could actually introduce one of the California oaks into their garden. NAN STERMAN: Oh yeah, but you need to have a lot of room the scrub oaks tend be small. But the angle mine oaks and the coast live oaks those are big tree. ALISON ST JOHN: How long would it take; would they last for decades? NAN STERMAN: Oh yeah. We were just shooting video at the Hurst castle and William Randolph Hurst was so enamored of his oaks when he designed and built his buildings he built around the oaks and when he couldn't actually dig them up and moved them these were centuries old oak trees, they will live hundreds of years. ALISON ST JOHN: So that is a long term decision? NAN STERMAN: Oh yeah. ALISON ST JOHN: So just in the minute we have left the San Diego county water authority has told us to turn off our irrigation systems to which I think many people have done, partly for the bills; but how long do you think that you could leave your garden without turning it back on again if you had native plants? NAN STERMAN: Well, the thing is you use the moisture sensors on the end of your arm, your ten little moisture sensors and you want to stick your fingers in the soil. If you have native plants and they are established you could pretty much leave the water off. I don't water any of my natives at all, ever, and they've been in the ground about 15 years. But if they are in the establishment period you want to keep the soil damp, not wet, but damp through the winter and that's when you turn your water on when they dry out more than that. ALISON ST JOHN: Great, okay. Thank you so much forgiving us insight into how to introduce native plants into our landscaping. That's Nan Sterman who is an author and gardening expert here in San Diego. Thanks so much for joining us, Nan. NAN STERMAN: Thank you.

Gardening Tips From Nan Sterman

  • Frame views with two tall plants
  • Don't place spiky plants along walkways
  • Don't put anything that will grow tall in front of a window
  • Layer plants from the largest to the smallest

The lack of water in California may cause some people to think twice about the plants they add to their garden.

But just because a plant is identified as drought-resilient doesn’t mean it won’t need water.

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Gardening expert Nan Sterman, who has written three books on gardening with native and low-water plant species, said drought-tolerant plants will need water until their roots have been established.

“All plants need an establishment period and they need to be kept damp, not wet, but damp so they have the chance to root,” Sterman told KPBS Midday Edition on Wednesday. “You have to water them until they are established and then you can cut back.”

Sterman said it can take more than a year for a plant to establish its roots.

Another common mistake people make when buying plants is not taking the size of the plant into consideration, she said.

When plants are too large, they will require more pruning, which leads to more green waste. Sterman said picking smaller plants will result in less work for gardeners.

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She said the best variety of plants to have this time of year are those suited for California's Mediterranean climate and plants native to the four other Mediterranean climates of the world. She recommended chaparral, sage and liacs.

"Because it's cool, the plants don't get heat stressed," Sterman said. "[Plants] don't go through so much transplant shock when the weather cools."

Her best tip: pay attention to the plant.

“It's really more trial and error,” she said.