Nan Sterman, garden designer and author of "California Gardener's Guide Volume II" and "Waterwise Plants for the Southwest." She also writes a Garden column for U-T San Diego.
Related Story: Tending Your Winter Garden In San Diego
CAVANAUGH: The beauty of gardening here is it never really ends. But it does change in the winter. Nan Sterman is here to talk about December in the garden. She is a garden designer, author of Water-wise Plants for the Southwest, and host of the upcoming KPBS TV show A Growing Passion. It's good to see you.
STERMAN: So nice to see you.
CAVANAUGH: Right after the show, Nan will be hosting a live chat for all your garden questions at KPBS.org. You say that it's a blessing and a curse that our climate doesn't force people out of their gardens and put them to bed for the winter. What is the curse? What's the downside of being able to garden all year long?
STERMAN: You never get a break. This is the time of year when companies start sending out seed catalogs, like dream about your springtime garden. We don't have time! We're out there doing the gardening. And a lot of friends in other parts of the country, this time of year, they put the garden to bed for the winter. They unplant lots of plants. And here we're just doing the opposite. This is our spring, this is when we start planting. You never get a break to sit by the fire and dream about what you want to do! It's exhausting!
CAVANAUGH: But gardeners can still use this time to clean up though.
STERMAN: Oh, always. Yes. Absolutely. And if you have a lot of deciduous plants, this is a good time for cleanup. This is when the plants lose their leaves. So you can stand back and look at the shape, where the branches are, and what do they need, do they need any pruning or is there any diseases on the trunks, etc. So it's a very good time for cleanup, but then again, any time is a good time for garden cleanup! You just have to have enough help to do it.
CAVANAUGH: What should people be cutting back?
STERMAN: Habitual, you can prune peaches and plums and apricots anytime after they start fruiting. The plants don't make as much energy to grow which means you can keep the trees shorter, which means the fruit is easier to reach. For many of us. Looking at a tree that has lots of leaves on Tit's much harder to see where the branches are to make cuts. Once you've done it a couple times, you see,
CAVANAUGH: And how do you figure out the wrong way to prune versus the right way to prune?
STERMAN: There's some skill to it. You prune out any branches, trees or shrubs, any branches that point toward the middle. You don't want things crossing branches that rub against each other, that rub point is going to be a wound. So you want to prune off at least one of those branches. The most important thing about pruning, whenever you prune, you always want to prune to a branching point. You don't ever want to leave a stub.
STERMAN: I see that all the time. When you leave a stub, are the leaves when they photosynthesize, they send the food down the branches all the way through the plant. If there's no leaves past that point on that branch, there's nothing to feed it, and that stub is going to die. It's going to become an avenue for disease and insects and all that, and it's ugly. So we never leave stubs. Really important. And it's something that most people, it just never occurs to them.
CAVANAUGH: The winter in most areas of San Diego has been -- nights are getting a little cold. But it's been rather mild for December.
STERMAN: It sure has.
CAVANAUGH: When do you start thinking about protecting your plants?
STERMAN: I know that Thanksgiving week typically is the week where I have to start protecting things. I happen to live in a microclimate where we get to the upper 20s every winter. I live a few miles from the beach, but it's a low spot. There are certain succulents that I really need to cover. I have a big garden. Some of the lower areas I may need to make sure I don't have pots of lemon grass there because they'll die back. Of right up near the house where it's warmer, they do absolutely fine.
CAVANAUGH: So how do you protect what you need to protect?
STERMAN: Putting things up around, and figuring out what the warmest part of your property is, first of all. Usually it's where it's sunniest. That's one thing to do. Another thing is you can get what looks like this white fabric. They call it floating row cover. And it's a very thin spun polyester of some sort. And you can spread that, drape it over the tops of your plants. That insulates the plants for a couple degrees. You don't want to leave plastic over your plants. You have problems with the magnification of the light, and you can damage your plants more by leaving the plastic on during the day.
CAVANAUGH: How about bringing in some potted plants?
STERMAN: Sure. I don't do that. Some people do. But if you have a nice warm sunny spot in the house, you can bring some things in. People who live where it gets really cold, they'll put plants in their basement or in their garage and let them sit there. They'll go into suspended animation: But when you're inside, you get very little air circulation. So plants become susceptible to bugs and scale and things like that. And inside the air tends to be dry and hot because we turn on the hotter. So you have to be really careful about keeping the plants watered but not too watered, and make sure that the leaves don't dry out.
CAVANAUGH: It's easier to find a warmer spot outside.
CAVANAUGH: We had a call or the line who couldn't stay, but the caller wanted to know when to plant potatoes.
STERMAN: As soon as they appear in the nursery, which should be right about now. You can get seed potatoes in the nursery. They start coming in around the time of the bare roots. And this would be a good time to do it. Now for the next couple months.
CAVANAUGH: What other things are ripe for planting now?
STERMAN: Ripe for planting, listen to you.
[ LAUGHTER ]
STERMAN: We're close to bare-root fruit season. Peaches, plumbs, nectarines, apples, etc., blueberries, strawberry, rhubarb, all these things that are typically bare-root, this is a good time. But really you could plant anything. All that's a native California plant would be perfect to plant now. Plants enter other Mediterranean regions, it's not such a great time. Citrus, bananas, you don't want to plant those now. Summer vegetables obviously you don't want to plant now. They're called summer vegetables because they like the heat. But any of these ornamental plants, this is the beginning of the prime planting season.
CAVANAUGH: Our gardens have different needs when the days are shorter, right?
STERMAN: Absolutely true. And the air is cooler, and it's moister. So this time of year, one more rainstorm and you can pretty much turn the water off. My irrigation has been off. It was accidentally off, I didn't realize it, because we had a leak and a fix, it's been off for two or three weeks. And unless we get a Santa Ana, it's pretty much a good time to turn the irrigation off. The plants, because it's cooler, and the air is more humid, they don't need that much extra water. That's what watering is, extra water.
CAVANAUGH: So if you're thinking about changing your irrigation system, this might be a good time to do it.
STERMAN: A very good time to do it. I'm updating a portion of my garden that has an old system that's been fine, but there's new technology they would rather use, so I'm changing all that out.
CAVANAUGH: For people who are going out to buy seasonal produce being grown around here, what's coming out of local gardens now?
STERMAN: This is when we make the shift over into a lot of leafy greens. Lettuces, spinach, kale. and the broccoli, cauliflower, brussel sprouts. The company is on the tip of my tongue! Cole crops. When we don't eat the fruit, but everything else. The carrots, potatoes, turnips, beets. This is when they are around a whole lot.
CAVANAUGH: Let me talk to you about the new project they know you're excited about coming up on KPBS TV. It's called a growing passion.
CAVANAUGH: What is it -- obviously it's going to be about gardening. But what kind of gardening?
STERMAN: Well, it's not just gardening.
STERMAN: It is everything that grows! We are trying to expose people to aspects of the county that they may not know exist. When you explore our county, what do you discover? What happens in every square inch of our county? Something grows. So we're going to be exploring all the ways that San Diego grows. We're going to visit some of the big, huge nurseries. And a lot of people don't realize that there are massive nurseries that grow ornamental plants that are shipped all over the country right here.
CAVANAUGH: I was surprised to learn that.
CAVANAUGH: I did a story on that once. It's one of our hidden treasures.
STERMAN: And one of our biggest industries. There are community gardens, school yard gardens, habitats that are undergoing restoration. All kinds of interesting stories about people who are learning new -- veterans who've come back from war and are learning to grow plants. We're going to explore issues of food justice. We're going to visit farmers and farmer's markets. Even backyard vineyards, olive growing, grape growing, the history of gardening. Lots of little segments on historical aspects of things that grow here.
CAVANAUGH: So you're going to be exposing people to the whole array of what gardens can produce, what the earth can produce here.
STERMAN: Exactly. What the earth produces, by a farmer or gardener or a grower or by Mother Nature, we're going to explore all of that.
CAVANAUGH: Are you going to be helping people grow plants? Are you going to be giving them tips the way you do here?
STERMAN: Every episode is going to have a how-to segment, a take-home, something that you can learn in your yard.
CAVANAUGH: And when will we see the first episode of this?
STERMAN: The good evening in May. We've begun shooting. We're in major fundraising mode right now. KPBS is very generous, but it takes more than what KPBS can provide. We've got some video shot, we're starting the first of the year, out in the field shooting a lot.