Your gardening questions answered!

S1: San Diego's unusually wet winter and spring have brought us emerald colored hillsides and a superbloom they can see from space. But what does that mean for your garden ? Joining me on Midday Edition is Nan Sterman , who we affectionately call our garden guru. She's been writing , speaking and teaching about gardening for decades. She is also the host of KPBS , A Growing Passion. And today , Nan will be answering some of your gardening questions. Nan , it's so good to talk to you again. It's great to talk to you , Maureen. Thanks for having me. Oh , I'm so glad you could make it. First off , I got to talk about the weather we've been experiencing this winter and spring. It's been wetter than it has been in recent years. It feels colder.

S2: Everything is behind not just because of the rain. The rain doesn't really impact that , but the cold , that long lingering cool weather we've had has really just put everything on the slow track. So what I expected to see happening in our gardens in terms of blooms and growth and all that kind of thing , maybe three weeks ago , you know , that's what I'm seeing now. We're several weeks behind and it's just it's like everything's kind of gone into slow motion. It's made it really , really interesting.

S1:

S2: So seeds are in the soil all the time. Okay. When when a plant flowers , after the flowers start to fade , they what happens is the fading is the process of making seeds the seeds of the next generation. The seeds drop. Or maybe they fly off in a bird poop or on the , you know , on your your shoe , the sole of your shoe or in your dogs or whatever. The seeds get dispersed , but they ultimately land in the soil. And it takes three things for a seeds to sprout. They have to have some kind of medium soil , potting soil or something like that. They have to have the right temperature and they have to have moisture. Those are the three main ingredients. Some need a little bit more , some needed a little bit different. But basically those are the three ingredients. So those seeds sit there dormant. They're just waiting for the right time , the right seeds and the temperature. Sometimes it's the day length and then when the moisture hits them , that activates them. Seeds are seeds are little embryos. They're little embryos sitting in suspended animation. And so when that moisture hits them , it activates them , they germinate , they start to grow and they flower. Some do it really , really , really quickly. Are are short lived. Annuals are like that and some take longer. That's when you get to perennial plants in larger plants. But that's what's happened is the rain triggers , they're the seeds to sprout. They go through their life cycle , they make those flowers. They know they have a really short time to do it and they drop their seeds for the next season and then they're gone. Okay.

S1: Okay. Wow. So we got the rain , but we also still have a lot of cloudy skies.

S2: We feel a little droopy , but the plants don't. There's plenty of solar radiation that gets through the clouds. That's just really not an issue. I mean , there's a difference between clouds overcast and shade , right ? Shade is when you're in a situation where the sunlight is blocked completely , but the overcast doesn't make that much difference. It's not like we're Seattle , though. It's felt a little bit like Seattle.

S1: It has. What makes San Diego a great place to garden.

S2: Wow , it's such a great question. We have such a wonderful climate that we can grow almost anything here as long as we have enough water. That's really our limiting factor is the rainfall. You know , normally we get nine , ten inches of rainfall this year. Escondido , there are parts of Escondido got almost 30in of rain. That's crazy. That's so much more than what we normally get. But we have that very moderate climate. We have tons of warm weather. Our soils are not great , but we have ways of getting around that. And it's just proven over the years when people try to grow plants from different regions that there are more plants from other areas that grow here than almost anywhere else. Now , that said , there's some things we don't grow very well , like we don't grow , you know , true lilacs. I was just up in Paso Robles this last weekend and when we arrived in the old downtown area and we stayed in an Airbnb and one of those old Victorians , the air , we got there late in the afternoon and the air was just perfumed because the lilacs are blooming. And I was actually a little surprised to see them because lilacs true lilacs , not our California lilacs , which really aren't lilacs. True lilacs require a period of chill cold that we down here in the flats. We don't get up in the mountains. You go to Julian ? Yes. They get it up there , but from the coast into the foothills , we just don't get that cold. Same thing for tulips. Anything that needs a winter chill. And that really doesn't do very well here. But almost everything else does great.

S1: Well , I want to get to our audience questions. We asked listeners to send in their questions. And and one topic in particular came up over and over pests. Here's a question from Sarah from La mesa. With a concern about skunks.

S3: With all the rain we've been having , the skunks are abundant and continue to dig for grubs in my vegetable garden. And I'm wondering what advice or guidance there is to help reduce them in the garden and keep the veggies growing and the skunks out.

S2: I'm saying only because the only thing you can do to keep skunks out is to physically exclude them , like putting a cage around your plants. Skunks , they're they're not going after your plants. They're going after those fat grubs , those big white , fat grubs that live in the soil in your garden. They happen to be some in your vegetable garden. And so they're going and they're digging in there to get those juicy grubs in the process. They disrupt your plant roots , but they're not going for the plants. They're going for the grubs. The only way to keep them out , literally , is to exclude them. So if if you have a place where they tend to nest or hide , wait till they're out of the nest and then go in there and board up that access. They're just they're part of the environment. We really can't stop them. We can just sort of encourage them to move on.

S1: And if you do encourage them to move on , do it very carefully , I would imagine.

S2: Yeah , well , you don't want to do it when they're present for sure. And , you know , do it. Do it in a way that's not going to hurt them. I mean , you don't want to hurt them. You just want to encourage them to go somewhere else.

S1: This is KPBS Midday Edition. And I'm speaking to KPBS gardening expert , the host of A Growing Passion , Nan Sterman. Now , Nan , other listeners are battling smaller pests. Karen from Poway is concerned about how to keep snails at bay who are eating her roses.

S4: We've tried coffee grounds , crushed eggshells , table salt , beer baits and diatomaceous earth to no avail. To make matters worse , did snails attract ants ? I hope you can help me.

S2: Okay , so first , let me address the issue of salt. Don't ever , ever , ever use salt in your garden. Salt on the soil literally destroys the soil. There is no coming back from that. You'll sterilize your soil and kill your plants. Don't ever use salt in your garden. Okay. I said that Now , as for the rest of what she was describing , you know , there's a lot of junk information you find out on the Internet. Coffee grounds don't make any difference. Eggshells don't make any difference. Diatomaceous earth may make a little bit of difference , but it's not long term. Truly , the only thing you can do for snails and slugs both is to use a product called Sluggo , which is not a poison. It is an iron phosphate. I think it's iron phosphate product that has replaced all the poison baits for snails and you just have to be persistent in using it again and again and again. Another thing you can do is go out at night with a plastic baggie and a headlamp and pick those snails off by hand. By hand. Yeah. Kind of fun. No.

S5: No. Yeah.

S2: I mean , you can wear gloves and you can find you can do it during the day , too. But snails and slugs tend to come out at night when it's cool. This is normally when people have. A snail and slug problem. What I tell them is they're watering too much because snails and slugs like damp places. So if you keep your garden adequately watered but not over watered , you won't have much problem with snails. But of course , this year , with all the rain , every place is wet. So it is truly a matter of keeping up with the Sluggo , physically removing them and encouraging birds because birds will come and they'll eat your snails and slugs.

S1: Well , I want to get you as many listener questions as I can. We have another message from Virginia Rinker , who has an aphid problem.

S6: I have a question regarding my diploid DNA , which continues to get infested with aphids and I can't seem to solve the problem. I've tried a strong spray of water , to no avail , and I wonder if you might have any suggestions. Thank you so much.

S2: Okay , so you're on the right track. You've got to use a strong spray of water. My favorite way to do it is to get a little nozzle if fits on the end of a hose. It's called a bug blaster. It makes a very sharp fan of water in 360 degrees or close to that. And you want to spray the the stems , the under leaves , the top of the leaves , etcetera. You also want to make sure that there are no ants on your plants. Sorry , that's a bad pun , but ants do this interesting thing. Ants farm aphids. They move them around the garden because what aphids do , they're sucking insects and they suck out the sweet , sugary photosynthetic from the plant and they kind of poop it out. They call it honeydew , a little drop on their on their backsides. The ants collect that sweet honeydew and take it to the nest to feed the ants in the colony. So ants will literally move aphids , carry foods around your garden to the plants they think are going to be the best producers. So if you're if there are ants present , you have to control the ants. And I like to use taro ant bait , which little they do. They have several different forms. So it's very easy thing to do. Terror ant baits to control the ants and then spray off those aphids. But you have to do it like every couple of days because they have a very short life cycle. They're reproducing constantly. What you need to do is interrupt that life cycle. So once won't do it , you've got to do it like every other day for several weeks. It seems like a lot of work , but it's the best way to do it.

S1: Another pest we heard about from listeners is tomato horn worms , which do not sound attractive. Listener Alan Risley writes , quote , I love growing tomatoes and hot peppers and containers on my condo balcony. Last year , my garden was attacked by tomato horn worms.

S2: Tomato horn rooms are actually really beautiful. They're. They're big green worms with white and yellow markings , and they have these two what look like horns on their heads. But they can decimate your tomato plant in short order , and one day you don't have them and the next day you have them and they're huge and they're succulent. I mean , they're they're truly amazing. So there's two things to do for tomato horn worms. One is you can pick them off. You notice you have them when you see little round balls of green stuff on leaves. When you see that , that's that's their poop. And when you see that , you know you have tomato horns or when your leaves start to look like they're being skeletonized so you can pick them off and drop them in a can of water or water with a little bit of oil on top , that will kill them. And as a preventative , there is a biological pesticide called BT. The origin insists it's a bacteria. It was the very first biological pesticide. And what you can do is you can sprinkle that on your plants and the the hormones end up eating it and it kills them from the inside out. It's not toxic to anything other than worms and caterpillars. There's some kinds that are toxic to mosquito larvae. But you have to be very careful because it is toxic to caterpillars. So you don't want to use it anywhere where there are going to be the caterpillars of butterflies like monarchs or Gulf fritillary. So keep it away from passion vine. ET cetera. But if you just keep it localized on your tomatoes , it's. It's a great solution , but you can ask for it in the nursery. The letters b t.

S1: Well , tomatoes are a big issue for San Diego gardeners. We'll talk more about tomatoes and peach trees and how gardeners can make the most of our crazy weather with Nan Sterman when we come back after a short break. Tell us what's been going on in your garden this spring. Give us a call at (619) 452-0228 and leave a message or you can email us at midday at pbs.org. Coming up , more advice from gardening expert Nancy Sterman.

S2: The key to successful gardening is patience. So just be patient. It'll be better next year.

S1: You're listening to KPBS Midday Edition. You're listening to KPBS Midday Edition. I'm Maureen Cavanaugh and our gardening expert , Nancy Sterman , host of the KPBS TV program A Growing Passion , is back with us. Thanks for staying with us , Nan.

S2: My pleasure , Maureen.

S1: Here's another tomato issue listener Rachel Hart is grappling with. She writes , I've lived in San Diego for ten years and my tomatoes get a virus and die every single year.

S2: The first thing I would ask is , are you planting your tomatoes in the same place every year ? That's a big , big issue because we have different kinds of viruses and diseases that live in our soils that build up after you , after you plant your tomatoes. And if you plant your tomatoes in the same place every year , it only gets worse and worse. You get more and more viruses and pathogens in that soil because if you think of it this way , those are those microorganisms are in the soil. They're ubiquitous , They're there all the time. You put your their favorite food into the soil and they start eating it and their numbers expand so that the next year , when you put their favorite food , the tomatoes into the soil , their numbers are bigger and bigger and bigger , their populations explode. So what you need to do is you need to practice what we call crop rotation. And this applies to all the plants in the tomato or nightshade family , tomato , eggplant , pepper , tomato potatoes that we tend to grow potatoes differently. All those plants need to. What I do is I put them all into one of my beds in one year and the next year I move them into a different bed. And then the the third year I move them back to the first bed and the fourth year they go back to the second bed. So I have two sets of beds and I alternate them between those beds and what happens is you don't get that buildup of the pathogens that attack the tomatoes. So crop rotation is one solution. Another solution is to buy resistant varieties of tomato , whether you're starting from seed or seedling. Every tomato that is has resistances will be marked. It'll say for root , not nematode , and it'll say F for free cerium , wilt resistance and so on. Those resistances will really help. You have tomatoes that thrive rather than , you know , ending up with with brown leaves and plants that just don't produce anything.

S1:

S2: I tend to choose varieties of tomatoes more for the kind of tomato like I want to grow a cherry and I want to go to a slicer and I want to grow grape tomato. But when I'm choosing the varieties I'm going to plant , I always look for the most disease resistant varieties. And they and again , they have those letters. You can find the definitions online , the letters that will tell you they're abbreviations for what they're resistant to.

S1: Now we got a few listener questions about Leaf Curl.

S2: What happens is , again , it's a little tiny microbe that will infect the leaves and cause them to curl up. It makes them really ugly , but it doesn't make them toxic to the tree. You need to leave them on the tree. They will still photosynthesize. They will still contribute energy to the tree. They're important for the tree , but they're really ugly.

S1: Listener Barbara Diederich writes My three peach trees bloomed beautifully earlier this year. Now they look miserable with leaf curl. I sprayed them three times with copper tox , but don't see any improvement. Did all the rains encourage the fungi ? What can I do ? Yes.

S2: All the rains created the kind of conditions where fungi proliferate. In other words , they thrive there. Their populations just explode when the trees are dormant. You have to spray both with the copper fungicide and also with a light horticultural oil , not neem light horticultural oil between the two. Generally that takes care of peach leaf curl that this year is a little bit different. So we're really seeing a lot of peach leaf curl even on trees that were sprayed. You know , next year , assuming things are more normal that shouldn't happen. Just go through the regular routine. You spray three times , you wait two weeks in between , spraying more or less , and you do it when the trees are dormant. You cover every surface of the branches , the stems , everything you have to. Make sure that the leaves are all gone before you do that. But that usually takes care of it. And hopefully next year it will.

S1: We have another leaf curl question.

S2: But I would not do that. You know , it's too much of a risk. I would not spray anything now , and yet the fungus is already there. It's not going to suddenly make the leaves beautiful. So just just be patient. This is the key to successful gardening is patience , patience and observation. So just be patient. It'll be better next year.

S1: This is KPBS Midday Edition , and I'm speaking to KPBS gardening expert , the host of A Growing Passion , Nancy Sterman. You know , San Diego has so many areas with different kinds of growing conditions. We got this question from listener Jesse Brown. The listener says , I live less than one mile from the ocean , the bay and the estuary. I've had no luck growing much of anything , even tomatoes. The one exception seems to be lettuce , which grows great and has a nice salty taste , which I assume comes from the salt air.

S2: That's great. Yes. And and Jesse is right. When you live that close to the ocean because it's so cool , it's really hard to get tomatoes and peppers and warm season vegetables to ripen your cool season. Vegetables are do great. The broccolis , the cauliflower , the lettuce , the spinach. All of that will do great. Even root vegetables , radishes and carrots. The but but ripening a tomato or a pepper or an eggplant. That's really hard. And the best thing to do is to look for what's called a short season variety. Those varieties are generally bred to thrive in under cooler conditions. They don't need the accumulated heat or the accumulated sunlight. Well , probably more the heat than the sunlight in order to produce. So if you're going to have any chance of having success , go for a short season. So when you look for the plant description will say either days to maturity or days to harvest , go for the shortest number of days that you can find. So if there's tomatoes that are 85 days or 90 days or 60 days , get the 60 day tomato.

S1: We've got another tomato question. Our listener , Derek , has a question about sprouting seeds in pots.

S7: How many seedlings are too many for taking to the next stage ? For example , I planted a lot of tomato seeds , not expecting so many to sprout. They all sprouted. Should I separate them into new pots ? And when would be a good time to do that ? Thanks a lot.

S2: I love this question. So this is a really interesting point. You know , I teach every year , I teach seed starting workshops and I have an online seed starting course that's going right now. If anybody's interested , you can still start your vegetables. It's not too late. And what I teach is to start three seeds in a container. Why three ? Because if you start just one , you could have failure and then you have nothing. But if you start three , chances are you're going to get one seed. At least two grow. Usually all three grow. And then what you do is you pick the strongest of the seedlings and you sacrifice the others. I called in plant aside , and you do it by cutting those weaker ones at the base with the scissors , not pulling it out. So the thing is , when you try to move seedlings up to the next size , when you try to separate them and repot them , that is a major failure point. I don't advise doing that. I really don't advise doing that at all. I think it's really important to just depending on the size to start with the right size pot and to plant three seeds only let one grow and then you'll have the perfect plant or the perfect seedling to plant into your garden.

S1: So Derek should basically cut off all the other tomato growth in his pot and just let one of them grow.

S5: That's my advice. How many does he need ? Well.

S1: That's true.

S5:

S2: But you have to be really careful. It's really easy to kill them when they're at that phase.

S1: I want to get to this question , too , from listener Chioma. She says , I'm planning on crossbreeding citrus trees in my garden.

S2: That is a very. Ambitious undertaking breeding new varieties of fruit trees is a many year long process. 15 years. If you go watch the episode of a Growing passion we did called From Fruit to Nuts. We trace the entire process of breeding stone fruits and breeding. Citrus is a very analogous kind of process. What you do is you have to have two different varieties that are compatible with each other. Not all are compatible , meaning that if you put the pollen from one flower onto the the female parts of the flower on the other tree doesn't mean that it's going to work because they aren't all some of them are sterile. But what So it's going to take ten , 15 years before you even know whether you've made a good cross. And the other thing is we don't start citrus from seeds. When you go to the nursery to buy a citrus tree , you're not buying a citrus tree. That was started from a seed. What you're buying is a grafted tree. That means that there was one tree that made really good fruit and one tree that had great roots. Those two were grafted together. They took a bud or a piece of wood from the really good fruiting tree and inserted it into the wood of the good roots and then grew it into a tree. And that's what you have at home. It's really complicated if you're a beginner. I don't advise it because it's there's so much more to it than you can imagine. Give yourself 5 or 10 years of growing citrus or growing anything before you start that. Watch your plants , observe them. Take some classes. Contact the citrus Collection at UC Riverside. They have an amazing citrus collection and we did an episode on that as well. Learn about citrus , learn about breeding , learn about cross-pollinating and then try your hand at it.

S1: And I just want to end it by asking you , you know , you've been at this a long time.

S2:

S5: Oh , my God.

S2: Gardening is a passion. I mean , you know , that's how we came up with the name of growing passion. The thing about gardening is there's so much to know , and you can never know it all. I'm constantly learning new things. Things constantly change. There's always new varieties of plants. There's always something that's new on the market. There's always a new pest , There's always a new way of doing things. There's always a better way of doing things. I get to experiment and and create new ways of presenting information. There's , you know , when I'm designing gardens , they're never the same. They're always custom. And it's always interesting and fascinating and delightful to come to the point of view. Like right now , when flowers are blooming and I may have used the same plants in two or 3 or 4 different gardens , but they look completely different. And then to have gardens on tour and to see people's response to the beauty that I've managed to create and then have them ask me questions about how can I do that myself ? It's there's no end to it and it's just wonderful. It's just a wonderful thing to do.

S1: Well , it's been wonderful speaking with you , Nan. Nan Sturman , garden guru , expert , teacher , writer. Thank you for sharing so much information with us. Really appreciate it.

S2: Well , thank you so much for asking me. Maureen , it's always a pleasure to talk with you.