293 Codling Moth Controls for Apples. Succulents vs. Winter

Show Transcript

293 Codling Moths, Succulents TRANSCRIPT

Farmer Fred

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Welcome to the Garden Basics with Farmer Fred podcast. If you're just a beginning gardener or you want good gardening information, you've come to the right spot.

Farmer Fred

One listener writes in and asks, what is boring the holes in my Fuji Apples? More than likely, it is the larvae of the codling moth, a pest that commonly attacks apples and pears. Unfortunately, codling moth is one of the more difficult to control garden pests. However, America’s Favorite Retired College Horticultural Professor, Debbie Flower is here, and we have tips.

Also, the plant lady, Marlene Simon has advice on how to protect your outdoor succulents from the ravages of a frost or freeze this time of year.

We’re podcasting from Barking Dog Studios here in the beautiful Abutilon Jungle in Suburban Purgatory, it’s the Garden Basics with Farmer Fred podcast, brought to you today by Smart Pots and Dave Wilson Nursery. Let’s go!

CODLING MOTH CONTROL IN APPLES

Farmer Fred

We like to answer your garden questions here on the Garden Basics podcast. Debbie Flower is here, America's favorite retired college horticultural professor. We get a question from Roland. He is in the high desert, in Southern California, zone nine B. He says, “Hello, Farmer Fred. My name is Roland.  I'm in a desperate need to get an answer to what's boring the holes in my Fuji apple.”

Apples holes? Sounds like codling moth.

Debbie Flower

Sure does. Yeah.

Farmer Fred

Yeah. And what's interesting is, you could probably cut that apple open and not find the pest. It could have escaped.

Debbie Flower

it could have, right, or you find it and you just cut it out and eat the rest.

Farmer Fred

Controlling the coddling moth. Wow, what's their range? Miles?

Debbie Flower

Yeah, they're flying. The moth can travel and things that fly are often difficult to control, but they lay eggs on the outside of apples and pears. And then the eggs hatch and the larva bore the  hole into the fruit, where they eat the fruit and grow bigger and eat the fruit and grow bigger, and eventually pupate and become a moth. That's what's causing the damage. And it starts all over again.

There's multiple generations.

Farmer Fred

Yeah, like three?

Debbie Flower

I think it's several.

Farmer Fred

You almost have to be a mathematical genius, if you want to try to calculate when the coddling moth is going to hit your yard. It's a matter of growing degree days. I'll let you figure that one out.

Debbie Flower

Right. Another way to find out if the codling moth is in your trees is to check your plants. Go out and look at those apples. Unfortunately, apples bloom in a cluster. So there will be five flowers in a cluster. The central one is called the King Flower, and typically is believed to make the bigger fruit if you remove the four around it.

Farmer Fred

the King Flower.

Debbie Flower

The King Flower, yeah, yeah. But many people don't do that kind of thinning. Nature does something on her own. But if all or multiples of those flowers develop, you often have fruit touching each other in that cluster. The codling moth often lay their eggs, where the fruit touch each other. And so what you're looking for, is basically a mound of orange frass, which would be pieces of apple that either have or haven't gone through the gut of the larva and have been deposited on the surface because there's not room enough for the larva and the frass and the apple all inside. And it's going to be small. You would start this examination of your fruit about six weeks after pollination. So just keep track of when the flowers fall off, and assume that's pollination. Put six weeks on your calendar, go out and walk around, find the fruit. If they're infested, take them out and destroy them. The fruit at this point is very small.

Farmer Fred

It is very small, the size of your thumb.

Debbie Flower

Yes, and the hole is going to be the size of a the tip of a pin.

Farmer Fred

But I think that's good advice though about thinning it out, then, to the King Flower, right?

Debbie Flower

In commercial production. They use chemicals, plant hormones, that are bottled. And you spray it on the trees to cause a lot of the flowers, a lot of the fruit, to fall off, so that we get these big apples that you see in the grocery store. In home production, without that thinning, you typically get smaller fruit. And you have this potential for the codling moth to hide from you where these two fruits touch each other, and you can't even see the hole. So you have to do some good looking, use your hands, move things around.

It's a big argument for keeping the trees short, so that you can get to the fruit. And the sooner you get those codling moth larva removed, the lower your population is going to be over time. And it sounds to me, like Roland has not gotten to them soon enough. And so he has a big population.

Farmer Fred

Yeah, most people don't even think about their apples when they're just teeny tiny, right after flowering stage.

Debbie Flower

But that is the critical time. And if you start seeing those little holes, you want to thin them out. Another way to time their arrival, when you're going to do your checking of those fruit, is to buy a pheromone trap. Pheromones are like hormones,  you can't smell it. But it's specific to the codling moth, and it's a mating hormone. And so it attracts the flying adult who's looking for a mate to copulate with him, then they have laid these eggs. And so the traps will have pheromones and stickiness in it, and the adults will fly in and get stuck. Well, now you know, they're in the neighborhood. Pretty soon, they're gonna start laying eggs. So give it maybe a week, and then you're gonna go out and start looking for those little pinholes.

Farmer Fred

I was reading here from the University of California, about how you can do this in your home without breaking out your degree day calculator. And it says, “Check your fruit at least twice a week, looking. The first things are the tiny mounds of the frass that you talked about. If you scrape away the frass, you'll see the tiny entry hole where the newly hatched larvae have just entered the fruit. Be sure to examine, as you said, the fruit where it touches another fruit. This is a common place. Spray the tree as soon as you see the first sting. However, first remove any fruit with stings from the tree. As the insecticide won't kill any larva that have already entered the fruit. Expect to have more damage with this monitoring method than the degree day method. It can be difficult to find.” Yes, it's like you don't have a life. You spend your time on the yard checking every little itty bitty apple on the tree looking for little stings and orange frass. I'll have a link, by the way, to the degree day calculator to help you out in this. Now we come to the subject of sprays, right?

Debbie Flower

Yeah, so the sprays are going to be on the outside of the fruit. And when the larva bite into the fruit, they're gonna get a mouthful and it's gonna kill them.

Farmer Fred

So there's a fairly new biological insecticide called CYD-X, C-Y-D  dash X. It's a granulosus virus that affects only the caterpillar, that’s the larva stage of the codling moth, and it's available to home gardeners here in California for one state, coddling moth larva must ingest this virus for it to be effective. Once ingested, the virus infects the digestive tract of the caterpillar, causing a disease that kills it within three to seven days. It doesn't affect other insects, humans, pets or wildlife. It's OMRI listed as suitable for use in certified organic production. And the University of California trials have shown that this product, when applied weekly during egg hatch throughout the season, is as effective as Carbaryl sprays. Boo, Carbaryl. Controlling codling moth in backyard trees, more applications are needed, though. For this to work. CYD- X also has the advantage of having no pre harvest interval. That means applications can be made up until the time of harvest. And there's no limit on the number of times you can spray it and of course, read and follow all label directions.

Debbie Flower

And so this is a really nice pesticide. It's the kind we've started looking for many years ago that is specific to the pest we're trying to control. It doesn't harm bees and other insects or frogs or pets or humans or anybody else.

Farmer Fred

Another registered, I wouldn't say safe, but at least less toxic, chemical spray that you can use is Spinosad, which is a biological product. It's a bacteria, right?

Debbie Flower

Yeah. Right. So there's a bacteria and a virus spray. Spinosad has a broader spectrum. It will harm other things than just the codling moth, and I don't have the list in front of me. But it is sometimes also included in slug bait, iron phosphate slug bait, to do earwig control. I was cutting an apple that my neighbor gave me from her tree, and there was an earwig in the hole and in the fruit. I think it just took over somebody else's hole. But I took it outside, and threw it in the garden.

Farmer Fred

If you really have a lot of spare time, you could bag your young fruit, right? Yes, you can buy a little netted bags.

Debbie Flower

Well, they say the nylon bags won't work. They should be paper.

Farmer Fred

Really? Okay. I was thinking of my other deciduous fruit trees in the Prunus family as opposed to the apples. So that yes, bagging the fruits is time consuming.

Debbie Flower

Imagine that. And the paper bags  also impedes the development of red color on the fruit. Red, in all cases, requires energy from light to form in plants. A red leaved plant can often take more heat than a green leaf plant of the same species, because the red adds extra pigment in the leaf to absorb the energy from the sun. That's probably more than you want to know. But a bagged apple will not turn red. So that's something to consider if that's critical to you. But there are specific types of bags that need to be used.

Farmer Fred

number two paper bags, right?

Debbie Flower

There are some cotton ones that some people have used that have worked, but nylon ones apparently aren't effective. My guess is that mesh is not tight enough to prohibit the adult moth from laying her eggs on the fruit. This is a very time consuming project because with the number two paper bags, it's cutting a two inch slit in the bottom fold of each bag, thin the fruit to one per cluster, slip the remaining thinned fruit through the two inch slit so that it forms a seal around the stem and staple the opening shut. But it won't work with certain short stem varieties, like Gravenstein.

Farmer Fred

Thanks. All right. Or you live with it.

Debbie Flower

Or you live with it. Yeah, they are still edible. It's just that there's a pathway through there with the larvas remains, for us in particular, and you just cut it out.

Farmer Fred

Make it a neighborhood project, because those moths are going to be in your other neighbors yards, as well. They're going to have them also. Will they overwinter in dead apple trees?

Debbie Flower

They will overwinter. Well, I shouldn't say that without reading. I was gonna say they could live in mummies, but I don't know if that's true.

Farmer Fred

Codling moths overwinter as full grown larvae within thick silken cocoons under loose scales of bark and soil or debris around the base of the tree, according to the University of California. So I guess they could do so in a dead tree.

Debbie Flower

Yeah, when I read that I thought, well, then I would use a horticultural oil to suffocate them. But apparently it's not very effective. I would guess that the cocoon prevents the horticultural oil from getting to the body of the larva. And the way horticultural oil works is to suffocate the animal by covering its breathing pores, which are in its rear end with the oil and plugging them.

Farmer Fred

What a way to go.  But the oil has been found to be an effective adjuvant, if that's the word, with the CYD-X granulosus virus or with Spinosad.

Debbie Flower

So “adjuvant” meaning…

Farmer Fred

adjuvant: extra ingredient, an extra ingredient.

Debbie Flower

Yeah, it helps to have, like a synergism. They help. Synergism, adjuvant. Yeah, that's synergism is probably not the right word. It just is more effective to use the two together than just one.

Farmer Fred

But there are restrictions on using oil, too, especially in heat.

Debbie Flower

Yeah, so we can get hot, fast, in spring.

Farmer Fred

So there's that. Read and follow all label directions. I liked the idea of just thinning to one fruit. I mean, that's gonna give you bigger apples for one thing, right? But it's a lot of work it is and then watch for the infected fruit, the stings, or you go to the farmers market on Saturday and buy apples.

Debbie Flower

Yes. I've sometimes in frustration thought about not growing edibles. Just going to the farmers market. And just grow flowers instead.

Farmer Fred

Well, there's that, I understand that. So Roland, chances are, that boring pest is a codling moth, and we'll have all sorts of links in today's show notes about  codling moths, and growing degree days and all that fun stuff there. Thanks, Debbie.

Debbie Flower

You're welcome, Fred.

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OUTDOOR SUCCULENTS VS WINTER

Farmer Fred

If you have succulents you know the danger of frost; and, it depends really where you live. In USDA zone nine the average frost season is usually December 1 through March 1 in zone eight December first through April 1 USDA zone seven November 15 through April 15. Anyway, if you have succulents, be it probably USDA zones nine, eight or seven, you need to protect them when the temperature is threatened to get below 32 degrees. We're talking with Marlene Simon, host and producer of the Flowe rPower Garden Hour podcast. You can find her on Instagram, Facebook and YouTube at Marlene the plant lady and she works with succulents every day, Marlene, what is it you do for a living?

Marlene Simon

I call myself the staff horticulturalist. So, a horticulturalist. I take care of plants at the UC Davis Botanical Conservatory. In our collection, we haven't counted, but we think we have around 4000 different species of plants, and a lot of them are under glass. And these are plants that obviously can't grow outside in our area. So yeah, we even have succulents under glass because as you were saying, you know, some have to be protected from  the cold actually, in some even don't even like temperatures below 50. You know, it really just depends on where they're native to.

Farmer Fred

What is the temperature inside the conservatory? What's the range?

Marlene Simon

Usually for our succulent room, we try not to allow it to to get below 65 but it will sometimes get down to about 55. it's all greenhouse, it's really difficult to keep, you know the parameters. It's big parameter swings.

Farmer Fred

Basically, having all those plants nearby gives you plenty of photo opportunities and I would invite listeners to check out your Instagram feed for pictures of wild and crazy plants.

Marlene Simon

Yeah, some of them are quite unusual. And some of our succulents are quite unusual. We also are known for being one of the first to get the corpse plant, the amorphophallus titanum to bloom. We have a collection of carnivorous plants and the miracle berry the one that when you eat something sour, you eat a miracle Berry and afterwards it makes the sour taste sweet. So you know we have a hodgepodge. Some very rare plants too.

Farmer Fred

By the way the corpse plant is true to its name. If you like the smell of rotting flesh, take a gander, take a sniff the next time somebody in your area says a corpse plant is blooming.

Marlene Simon

Yeah. If you know the smell of death, that it's a very distinct smell good. Like how do you know the smell of death? Well, we have rats that die in the greenhouse.

Farmer Fred

And it's a flytrap too.

Marlene Simon

Well, it's pollinated by flies and dung beetles. So they like that smell because they like rotting things and dead things and they lay their eggs on it because that's what their babies eat. But then they get tricked and they lay their eggs on it. But as they're walking around the flowers, they pick up the pollen and move to another one.

Farmer Fred

Folks, I bet you didn't know flies could be pollinators

Marlene Simon

Number three pollinator in the world. Whoa, yeah.

Farmer Fred

Well then who's number one and number two?

Marlene Simon

Number one, bees and wasps. They group them together. Number two, butterflies and moths. And number three are flies.

Farmer Fred

Wow. Yeah. So be careful with that flyswatter.

Marlene Simon

Maybe not so much your house flies.

Farmer Fred

All right. Well, we're here to talk about succulents and frost who knows more than you? I don't know.

Marlene Simon

A lot of people do know about succulents. There are some amazing, amazing collectors out there.

Farmer Fred

Let's define first of all what a succulent is.

Marlene Simon

Perfect. Okay. So, you know, I posted a picture of a cactus and a follower said, Oh, isn't that in the succulent family? It's a succulent. Basically even saying "succulent" it's a descriptor. It's saying almost like a shrub or a ground cover. A succulent is any plant that has an abundant or more than normal amount of moisture stored in their leaves or stems and of course, most of them were found in dry desert areas, but not necessarily. I've considered Plumeria to be a succulent, like so really, it's just it's just a way of storing water for them. And there's whole bunch of different succulents in different families, of course, the most famous families, probably the cactus family, which is the cactaceae. And then you have the Euphorbia family, which is found all over the world, your crassulaceae family, you know, echevierrias and sedums that people grow or the cute ones dideraceae family that's only found on Madagascar. You know, we've been considered, like I said, the Plumeria there's even members of the cucumber that are considered quote, a little bit succulent.

Farmer Fred

Talk about growing plants outside their home region. How many people have gone to Hawaii, marveled at the Plumeria, and then bought a cutting home from over there, brought it home, sprouted it. And next thing you know is it's looking beautiful out there on the back porch, and then October comes and all of a sudden it sort of goes into decline and that's why a lot of people bring their plumerias indoors in the wintertime.

Marlene Simon

That is correct. And that's really the safest way. A lot of times you can have like at the Conservatory, we have multiple ones but they're between the greenhouses, they're tucked in amongst plants. So the two greenhouses, of course, radiate some heat. They're undercover because as they drop leafs and go dormant, you want to taper off the water so you don't want the winter rains to just bombard them. So if you bring them inside, expect for them to drop their leafs and then taper back the water but then yes, move them outside as soon as you can, because as soon as they break dormancy, there's not enough light inside even by a sunny window is still not as sunny as a filtered shade area. Spider mites are a huge thing with plumeria too. So if you don't kill it with the frost, spider mites are gonna get them.

Farmer Fred

if it isn't one thing, it's another, of course.  Well, I guess a good tip then for those raising succulents in climates that get below 32 degrees would be keep them in containers you can easily move.

Marlene Simon

Yes. So, you know, as I was describing, succulents are found all over the world. There's even a cactus species up in Canada, so that cacti species could handle like negative 20 degrees. And if you look at some of our deserts in SoCal and Arizona, there's cacti covered in in snow, for the most part, a lot of cacti because they're only found in North and South America, if they're not from South American that in the tropical regions, they could handle being in the ground. As long as there's good drainage, that's key through the winter. Now, if you take a certain aloe from one location from South Africa, that their temperatures never get below, you know, 45 it could be a 45 degree night or a 40 degree night that could be detrimental to your plants. So when people ask me, what should I do to my succulents for the winter, I say, Well, if you don't know where they're native to, or you don't know the name, and you can't research where they're native to, when in doubt, of course grow them in pots so you can move on either inside or up close to the house, cover them with the sheet, of course not plastic, take it off, you know, the next day when it warms up. And then if you have it in the ground and it hasn't gone through a winter, cover it, but you really ideally I hate when nurseries don't label their succulents. They just label them. succulent plant.

Farmer Fred

Yeah, exactly.

Marlene Simon

That's a plant. So really, it's it's the cold but also they need really good drainage in the winter too. So that's the other reason why in pots are great because you can move them up under the under eaves of your house. If they're just in sopping, sopping wet water, you know, there's they could, you know, the roots could get rotted away. What they do is they actually if you notice your succulents sort of wrinkling in winter, they actually move some of the moisture out of their leafs to prevent in case there is cold. You never want to go into a frost with your succulent well watered in because that's like you know, if you put water in something and you freeze it and expands, it could literally burst cells whereas with leafy plants, you want to go into a frost with them well watered in because if they're not that means they're stressed and they're not going to handle the frost as well. So if you notice your your succulents are wrinkling, it could be that it's moving the moisture out and it's protecting itself it's doing its job.

Farmer Fred

Excellent tip because a lot of people who live in citrus growing regions are very used to watering their citrus before an expected frost or freeze to sort of insulate the soil from lower temperatures. However, succulents, that's a different story. you don't want wet succulent soil going into a frost or freeze.

Marlene Simon

No you don't. It's just the way their vascular system is they have way more moisture. If there's any damage that occurs on the roots in bacteria enters it just has a field day with all that moisture. So that's one of the main reasons to is it's you know, bacteria is a big problem. But yeah, so there's it's sort of just the opposite of leafy plants. But I always say when in doubt, if you don't know the name of your succulent or you don't know where it's native to, and it hasn't been through a winter before. If it's already gone through a winter and we've had frost you should you know, you should know what story and you should go, Okay, it can handle this. Of course, you know there's those every time Yours we get severe frost. But you know I had a friend who is a big succulent grower. He was an expert in carnivorous plants. He moved into succulents. He redid his whole front yard in succulents. I have a picture of the first year he planted stuff and it looks like ghosts, because he has cotton sheets all over his plants. And then it just was too much work. So he decided, Okay, I'm not going to cover them. You know, I know where they're from. I know the names of them. They're borderline, we'll see. And, you know, they died. He's like, okay, it wasn't meant to be.

Farmer Fred

Exactly. You got to try it and see what happens. I think one mistake a lot of people make is they go into panic when the first frost  happens. And they forget to cover their plants or move their plants. And the next day they go outside and the plant looks okay. They figure, Oh, well, this plant must be frost hardy, then they forget about the plant. And then frost number two, frost number three, freeze number four, whatever happens, they go out in the yard, and oh, there's dead leaves.

Marlene Simon

Yeah, that's true, because it is it's sort of a cumulative effect, as well, you know, they might be able to handle one night of that, that freeze. And then you know, as more and more come along, the plant suffers more and more. If there is frost damage on your plant, of course, obviously move it inside or move it closer to the house, if you can't do that, cover it. But avoid pruning any of the sort of severe or the the frost damage off because that's the protecting the plant. If, of course, if you start noticing that turning brown and moving down the stem, cut about an inch past the brown, because that is showing you that there is more of a rot happening than just frost damage, but you never want to and this goes for leafy plants too. If something gets frost damage, leave it on there because it's sort of protecting and acting as a barrier for the future cold. But wait until spring when plants are actively growing to remove that specially your succulents when they warm up, then they could heal those wounds easier when you cut them.

Farmer Fred

You had a good point on a recent Instagram post about covering plants with frost cloths. And you stress that that frost cloth has to extend all the way down to the ground.

Marlene Simon

Yeah. Or under a pot if you have it in a pot. Or if you can't tuck it underneath a pot, at least pin it to the soil in the pot. Yeah, so I say it's ghosts or lollipops. And I think I read that somewhere. So it wasn't like I was that creative and came up with that. But it's a good, it's a good, maybe it was you even I don't know. So when you see, you know, think of a ghost, that sheet should be all the way down and pinned to the soil. And the reason being is if you have more soil, it's going to radiate heat up. And that's going to create a nice little greenhouse effect around that whole entire plant. Plus, you don't want the trunk being exposed as well if you make a lollipop and just sort of leave that the trunk exposed and you have the top just covered like a lollipop. So you're not getting the benefits of the soil heating up the plant and you're also leaving the the trunk exposed and to a certain extent sometimes that are really frost sensitive. Even you know, the roots that the soil. So yeah, make ghosts and not lollipops.

Farmer Fred

Exactly, yeah, especially with citrus. If you're covering trees with frost cloth, you want to extend that frost cloth canopy all the way to the ground, but at the outer drip line of the tree and secure it there. Because that allows more soil to radiate heat back up into the canopy of the tree.

Marlene Simon

Exactly, exactly. And you know, and you don't need to leave them on the following day. Someone mentioned like, Oh, I did this, and I got so many pests and ended up killing my plant. Well, they're not meant to be left on throughout the whole entire winter. Most of the plants only need it when we do get a frost or their temperatures go below what they're happy, like, you know, lemons, you know, I mean, I don't even I don't cover my finger lime. I wouldn't cover it unless it gets to 20. But then I would take it off the next day because we're gonna warm up to 50 or 60. And I want it to get the sunlight. So try not to be too lazy of a gardener. I mean, I'm guilty of that. I know. I know. But it's gonna benefit your plants, not something you want to leave on all winter.

Farmer Fred

Yeah, exactly. Let the sun shine through to help radiate some heat back onto the soil. Exactly. People may not reali