GB 078 Plant Partners 2628
SPEAKERS
Jessica Walliser, Ed Laivo, Farmer Fred
Farmer Fred 00:03
Welcome to the Garden Basics with Farmer Fred podcast. If you're just a beginning gardener or you want good gardening information, well, you've come to the right spot.
Farmer Fred 00:16
Do you want to help Mother Nature battle your garden pest problems? Well, give a listen and find out how Jessica Walliser is the author of "Plant Partners", a great book that has scientific proven strategies for incorporating different plants into your vegetable garden to fend off the bad guys by attracting the garden good guys. Also, how deep should you plant that new fruit tree? It's all on Episode 78 of the Garden Basics with Farmer Fred podcast. And we'll do it all in under 30 minutes. Let's go.
Farmer Fred 00:52
If you're familiar with the Farmer Fred Rant blog page, or anything we've been talking about here on the Garden Basics podcast for the last year, you know how I feel about attracting beneficial insects to your garden. It's such a great idea to bring in the good bugs to battle the bad bugs. You're going to use less chemicals, you're going to maintain a higher level of control. But you have to bring in what I like to call the good bug hotel, you have to build the good bug hotels to attract the beneficial insects. And if you think about that for a minute, that there are these plants that attract beneficials, and there are a whole host of plants. Maybe there are plants that attract the bad bugs. And you know, maybe it's because we've been doing the same thing over and over and over again, in our garden. When we plant our summer vegetable garden. We like to plant things neatly in a row. We have the tomatoes over here, the peppers over there, the squash over there. And the flowers, oh, they're probably ringing the yard. Well, what about instead of farming, we create a jungle. Now when this is all over, I may have to change my name from Farmer Fred to Jungle Jim, I'm not sure. But what is explained in the book, "Plant Partners, a Science-Based Companion Planning Strategies for the Vegetable Garden" by Jessica Walliser. In Plant Partners, there is a lot of talk in this book about how to thwart the bad bugs by incorporating the good bug hotels in your vegetable garden. We're talking with Jessica Walliser, author of Plant Partners. She's also the co-founder of savvygardening.com. And Jessica, it's a pleasure to talk to you about this because I really believe that beneficial insects, attracting the good guys to your garden, is a great way to battle pests. And the pest though will find the plants they want. But you can make it harder for them by incorporating something that you call in your book, the appropriate/inappropriate landings theory. And I gotta tell you, I'm in love with this.
Jessica Walliser 02:54
Well, thanks very much. And thanks for inviting me, Fred. I think I'm just gonna take to calling you jungle jim from here on out for the rest of the interview. And you can call me Jungle Jessica. How's that?
Farmer Fred 03:04
There we go.
Jessica Walliser 03:06
Yeah, so thank you for inviting me. Everything you just said is completely true. You can call it a jungle If you want, I prefer to call it a polyculture, where you're inter-planting a bunch of plants together, right? Because jungle makes it sound like it's messy and all that stuff. But really the type of garden environment we want to create is actually quite beautiful. It's a mixed planting. It's a polyculture of all kinds of different crops. And you mentioned the appropriate/inappropriate landings theory. And it's an important piece of scientific research that points to the value in having that kind of polyculture in your garden. And basically what this theory says is that, you know, a lot of pests that feed on our garden plants, they don't just necessarily find their host plant by a visual cue by, in other words, by sight, they also find it by landing on it. By landing on that plant, they have basically receptors on their feet, that allow them to recognize the plant that they're landing on as a host plant or not as a host plant for their egg laying behaviors. Right. So if we have our cabbage, all planted in a row together in the vegetable garden, and that cabbage worm moth is flying from plant to plant and landing every time on that plant, it needs to land a certain number of times before the egg laying behavior is triggered. If it's landing on a cabbage every single time, it's going to be able to trigger that egg laying much quicker, much, much more rapidly. Whereas if you interplant your cabbages with a whole host of other plants, when that butterfly lands, each time it lands, it's probably going to be landing on a different plant. And so the required number of triggers isn't there. And the egg laying behavior is reduced. And it's a really interesting research that took place in this and the researchers that looked at this appropriate/inappropriate landings theory found that 36% of the insects that were being studied, they were observed laying eggs on host plants when they were grown in bare soil, so 36% laid eggs, when the plants were grown in bare soil. Only 7% laid eggs on host plants that were surrounded by other plants, by other companion plants. So creating that jungle environment, or polyculture, can lead to a reduction in pests.
Farmer Fred 05:26
I never realized that bugs, including the bad bugs, taste with their feet.
Jessica Walliser 05:31
Yeah, not all bugs do. But yes, they also leave chemical messages behind when they walk on a plant. So a ladybug, for example, who knew? But ladybugs actually have stinky feet so to speak. And when they walk around on a colony of aphids feeding on aphids, which is one of their favorite foods, they leave chemical footprints behind. And those footprints are picked up by a lot of the species of parasitic wasps that also use those aphids as a host for their young they lay an egg inside of the aphid. And so if those parasitic wasps have picked up on the fact that a ladybug has walked there before, they're less likely to lay an egg in that aphid because they don't want their egg or their baby eaten by the ladybugs. So they'll fly off and go find another colony of aphids to lay their eggs on.
Farmer Fred 06:21
There are a whole host of plants that attract the parasitic mini-wasps. You have yarrow, dill, marguerites, coriander, cosmos. And Cosmos really appears in a lot of strategies for attracting a whole host of beneficial insects. Because it's a member of the composite or Asteraceae family. The good guys really like those flat flowers because they don't have that long probiscus for probing so they love the daisy-like flowers. So if you're going to intersperse with your vegetable garden, a lot of different summertime annuals, what are some of your favorites?
Jessica Walliser 07:00
Well, in Plant Partners, we actually look at some of the cool research that's out there, the scientific research that looks at what types of flowering plants we can use to enhance that biological control or the good bugs that we have in our gardens. And so that dill family that you mentioned, or carrot family, where everything has the structure of a double flower, if you think about that, which is actually an inflorescence. It's hundreds, if not 1000s of tiny flowers all put together to create that umbrella-like structure. Each one of those tiny flowers needs to be pollinated by a tiny insect. So those are great for attracting and supporting parasitic wasps in particular, but also ladybugs and lacewings and other good guys. So, you've got the dill, the fennel, the cilantro, Angelica, izea, which is a great native perennial. So anything with that umbrella shaped inflorescence is a good choice. Also for me, a lot of the flowering herbs in the mint family. So things like oregano, and basil. Yeah, you don't have to plant regular mint, which will take over the garden, of course, but a lot of things that have that high essential oil content. And then also you need to allow them to flower because they will provide nectar as well.
Farmer Fred 08:14
One herb that we like to grow out here in the cool season during the winter here in the western United States is cilantro. But cilantro starts bolting when the weather starts warming up in April in May. And a lot of people when they see the bolting, they'll rip out the plant. I like to keep cilantro in the yard, because those flowers attract a whole host of beneficials, including hoverflies. So like you say, it really pays to let those plants go to flower.
Jessica Walliser 08:41
It does. And then you get coriander if you harvest the seeds. And if you don't harvest the seeds and you let them drop, at least here in Pennsylvania, we end up with those seeds just laying on the soil all winter long under the snow. And they germinate first thing in the spring. And then I get a really wonderful early spring crop of cilantro. So you know lots of reasons to let them go.
Farmer Fred 09:06
I really like your book, "Plant Partners: science based companion planting strategies for the vegetable garden". When I first saw the title of the book, I go Oh, here we go again, marigolds and nematodes. But you don't even talk about that. And I'm so glad you don't. Because planting marigolds to control nematodes is a very iffy proposition. And what you have in here, and this is the impressive part of your book, is the bibliography. The fact that everything you talked about in this book is backed with scientific research, as outlined in the back of the book, many of it from peer-reviewed scientific journals. And I recognize a lot of names in here of people I know at UC Davis who do plant research. And of course, what really sold me on your book was the fact that the foreword to the book is written by Jeff Gilman. Jeff Gilman, and for those of you on Facebook, may know him as part of the Garden Professors. And an outstanding garden writer in his own rite. So by having Jeff Gilman in your book that kind of sells it.
Jessica Walliser 10:08
Well, good. I hope so. Yeah, I mean, he is such an iconic figure in the gardening community in terms of sort of dispelling garden myths and, you know, homemade remedies and all that kind of stuff. So I was thrilled that he decided he wanted to write the foreword for the book, it's a really important part of the book, as you mentioned,
Farmer Fred 10:28
One of my favorite chapters in the book has to do with trapping crops, and one pest that I think is probably universal in the United States in the backyard garden is aphids. What are some strategies for companion planting to control aphids?
Jessica Walliser 10:46
So for me, aphids are one of those pests that are, as you mentioned, that are everywhere, but there's also beneficial insects that eat them everywhere, right?
Farmer Fred 10:59
That's the whole idea.
Jessica Walliser 11:01
Right, right. I mean, they are the prey, right? So they are the gazelles and the you know, the ladybugs and lacewings and parasitic wasp and hoverflies, they are the lions, right? So, what we want to do is, we want to actually I like to encourage the aphids in my garden, because I know if I have aphids, I'm going to have a lot of good bugs around. They can also in turn, help me control many other pests that might be more challenging to control. So if you have aphids in your garden consistently, there are some plants that you should plant to support the biological control, and number one for me is sweet alyssum. And that's because sweet alyssum is very attractive to the hoverflies, whose larva feeds on aphids. And so they are number one, and you see that I know a lot of times in California, the lettuce farmers will interplant with sweet alyssum to help attract those good bugs. So that's one of the easiest ones that you can do. The one of the easiest plant partnerships that you can choose to help control those aphids.
Farmer Fred 12:02
In today's show notes, I'll have a link to one of the Farmer Fred Rants that gets many views. It's called "Plants that Attract Beneficial Insects". And in that post, I have pictures of the beneficial insects but not just the adult, but also the baby stage and the teenage stage. And like you mentioned, the hoverfly and the hoverfly teenage stage might be mistaken for a caterpillar, really the telltale sign of this green, caterpillar like critter that you know it's a hoverfly it has sort of a cream or yellow colored streak down its back. So before you start killing any bugs, identify the bug to make sure it isn't a good guy.
12:41
That is true. That is true. And we you know, our hoverflies that we have here. And I don't know that, you perhaps have different species out there. But most of our hoverfly larva that we have here in the eastern US sort of almost look slug-like, they're kind of clear, they're very, very tiny. They're, you know, not not much bigger than the aphids themselves. And they sort of crawl around on the plants around the aphids, and they're really fascinating. They're tapered at one end, and the end that they're tapered at is their head and, and they kind of swing their head, they don't have eyes. So they swing their head back and forth as they crawl over the plant until they bump into an aphid. And then of course they grab it and have it for lunch. So it's really cool once you learn how to identify all these good bugs in all their different life stages, as you mentioned, and then you can actually go out into your garden and watch them work. And that is the coolest thing. Like I am the nerd that is out there in my garden, you know, sitting on my rear in the garden, watching my plants and staring at them and find an aphid colony and I was so excited because I can't wait to see what good bugs I can find on it just when I stop and spend a couple minutes taking a look.
Farmer Fred 13:49
One of the joys of being a tomato gardener is seeing that tomato warm with what look like little white cotton q-tips on its back because you know then it has been parasitized.
Jessica Walliser 14:02
it is it's so thrilling when we see that in our garden, isn't it and a lot of people think that those are eggs of a parasitic wasp, like they're aware that it's a good bug, but they're not quite sure what's going on. But actually when you see those little white, they look like little grains of rice hanging off the back of that tomato or tobacco hornworm you're actually seeing the pupal case. So you're seeing the hatch of the larval wasp pupating into an adult wasp outside of the body of that hornworm. And what's really cool is if you can catch, what I have a couple pictures of in my various books is the larva kind of oozing out of the skin of the hornworm because they spend their entire larval life stage inside the body of that hornworm, and then when they're ready to pupate, they ooze out through the skin, spin those external cocoons and then pupate there and if you're really lucky, you can actually catch the adult wasp sort of shooing a round hole in the top of that pupil case, and popping it off, and then flying off to go do it all over again.
Farmer Fred 15:08
That is also the telltale sign of a dead aphid. If you turn over a leaf of a member of the squash family out here and you see a lot of brown or black specks. If you look really, really closely, they're probably dead aphids, and you may notice that brown or black circle on their back where they've been parasitized.
15:30
Yeah, I always say they look a regular aphid is lean and mean, a parasitized aphid is fat and sassy. So they're, they're plump and they're round, and they're often a brown or dark gray. And when they look different than healthy aphids, and the kind of their exoskeleton gets swollen and dry. And then yeah, when the adult aphidius wasp is ready to emerge, they chew what is a perfectly round hole in the back of that aphid Mummy, and they pop the top off like a manhole cover. And they emerge and again, fly off to do it all over again. It's just amazing.
Farmer Fred 16:09
I have a question about plant choices to incorporate in your vegetable garden. We've talked about many varieties of especially like I said, the composite family, the Asteraceae family, is there a difference between planting an heirloom variety versus a hybrid variety? Are the garden good guys more attracted to heirloom varieties of these flowers?
Jessica Walliser 16:35
That's an interesting question that you bring out. And I think the jury in many ways is still out on this. But there's a lot of research going on in particular with pollinators, where they're looking at, does the strict native species have a plant? Is it you know, does it support more pollinators than say cultivars, more modern cultivars of that plant? Does it? You know, is there something about the nectar composition that changes through that breeding process? And, you know, there's ongoing research about this. I think most of the preliminary research points to the fact that, yes, cultivars can support just as many pollinators and a diversity of pollinators as the straight species does. But they haven't looked at nectar fitness yet. You know, is it McDonald's? Does it become McDonald's nectar, or is it Whole Foods nectar, right? So does the nutrient content of that nectar change through that plant breeding? I mean, there's so many questions. And as far as I know, there's not much current research that takes all of that and looks at it in terms of predatory beneficial insects. So they're looking at pollinators, but maybe they aren't necessarily looking at the ladybug, who is also drinking that nectar and eating that pollen. So it's very complex. It's very complicated, and I'm not sure we're going to have clear answer soon. From my own personal standpoint, if I have a choice, I try to include as many, you know, native plants in my garden as possible. I do have cultivars in my garden as well. But I do try to avoid plants that have a you know, just an incredible amount of petals, you know, like the double varieties, often because they're nectaries can be really buried beneath all those petals, and inaccessible to a lot of these smaller beneficial insects. So I try to avoid those. They're great for human eyes, but I don't think they're quite so good for the insects.
Farmer Fred 18:30
Very good point there. Yeah, I haven't used chemicals to control insects in my yard in years just because of the plants that are in the yard along with the vegetables. And permanent plantings are very important to to help you control the pests. You talk about this in your book. So let's talk a minute or two about the bigger good guys, the birds and what they require. You talk in the book about hedgerows, which if you have a good sized piece of property, hedgerows, a permanent woody vegetation, is very important for attracting a permanency in your garden for the presence of birds, especially evergreen shrubs that produce berries.
Jessica Walliser 19:08
It's true, it's true, and not only for those birds, but also again for those good bugs and those pollinators. You know they need a place to take shelter in the winter, they need a place for egg laying. So something like an elderberry bush which is a hollow stemmed shrub, if you include those in your hedgerows, I mean that's a winner because you've got the berries for the birds, you've got the hollow stems which are pollinators and many of our beta beneficial insects will take shelter in for the winter. You've got, you know, habitat in their veins like structure for even for rabbits, right and birds that take shelter in the winter and nesting in those plants as well. So, some of the native viburnums are really good for the same number of things. So having a hedgerow, having permanent established plantings, whether they are shrubs or perennials or a mixture of both is really important to so many creatures and so many levels of the ecosystem of the garden.
Farmer Fred 20:06
You mentioned a piece of research that I'm very familiar with. The folks at UC Davis have studied hedgerows at this one ranch outside Davis, called the Oakdale Ranch, where they've constructed hedgerows and studied how many beneficial insects, how many good predators they attract. And like you were pointing out, it's really very much more effective if you use native plants.
Jessica Walliser 20:30
Exactly. And, you know, again, I think the sad part is in this day and age, beggars can't be choosers, right? I mean, I just want people to stop planting lawn and start planting flowers and you know, blooming plants and shrubs and trees and you know, some things with structure, I want them to start there. But then obviously, we all know that there's so many more benefits to be gained by using plants that are native to your region, there's a greater level of value in them. And there's a lot of research pointing to that, especially again, in terms of caterpillars, like butterfly caterpillars, moth caterpillars, yeah, they need plants that they co evolved with over millennia to support their caterpillars, there is no substitute for those guys, right, there's no option, there's no plan B, that's the only plant they can use for egg laying. So I think doing some research, looking into the plants that are suitable for hedgerows, wherever you live in the country is really, really valuable to do.
Farmer Fred 21:30
I think every state has some sort of organization or online presence that discusses the native plants for each state. Here in California, it's the California native plant society. cnps.org is their website. And they have a lot of good websites that can help you ascertain which are the best native plants to use for your very particular area, in the case of California. And I imagine it's like that, throughout the United States, every state has native plants and they work. What I like is we're reinforcing that old bumper sticker that says, "Mother Nature abhors a monoculture".
Jessica Walliser 22:07
Indeed. "Diversity Equals Stability" is my favorite one, I walked into a classroom one time to teach a class at a university. And it was actually written on the blackboard. And it said, diversity equals stability. And I took a picture of that Blackboard, and I use it in a lot of my presentations, because it's an important and valuable message. For gardeners. No matter what kind of garden you grow, but in particular, in the vegetable garden, the more you treat your garden, like an ecosystem with many layers of interacting plants, the better, more stable of an environment, it will be the less pest pressure, less disease pressure, you'll have the healthier soil that you'll have the healthy plants that you'll be able to grow, that diversity is really key. And you know, companion planting is actually planting for diversity, right? It's choosing to partner certain plants together for a benefit. But in the end, what you're doing is you're creating that polyculture, you're creating more diversity, which leads to a better, more stable environment.
Farmer Fred 23:09
The name of the book is "Plant Partners: Science-Based Companion Planting Strategies for the Vegetable Garden," it's by Jessica Walliser. She's also the co founder of savvy gardening.com. Jessica, we learned a lot today. Thanks so much for giving us some great advice about Plant Partners.
Jessica Walliser 23:26
Thank you very much for inviting me and I look forward to talking with you again.
Farmer Fred 23:36
The Garden Basics with Farmer Fred podcast has a lot of information posted at each episode: transcripts, links to any products or books mentioned during the show, and other helpful links for even more information. Plus, you can listen to just the portions of the show that interest you, it’s been divided into easily accessible chapters. Plus you’ll find more information about how to get in touch with us. Leave an audio question without making a phone call via Speakpipe, at speak pipe dot com. it’s easy, give it a try. And you just might hear your voice on the Garden Basics podcast! If you’re listening to us via Apple podcasts, put your question in the Ratings and Reviews section. Text us the question and pictures, or leave us your question at: 916-292-8964.916-292-8964. E-mail: fred@farmerfred.com . If you tell us where you’re from, that will help us greatly to accurately answer your garden questions. Because all gardening is local. In the show notes you’ll find links to all our social media outlets, including facebook, instagram, twitter, and youtube. Also, a link to the farmerfred.com website. And thanks for listening.
Farmer Fred 25:08
Here's a quick tip on how to plant a fruit tree from Ed Laivo from Tomorrow's Harvest.com. Many people are guilty of planting trees too deeply. When you plant a fruit tree, you want to be able to see that bud union sticking up maybe an inch or two above the soil line after you plant it.
Ed Laivo 25:32
Yep, that's a fact. The bud union, of course, is where the tree has been budded on to the rootstock. Probably a simple way to do that when you're planting a bare root tree is to just say the top most root, you know, if you go say three to four inches above that, that's typically a safe place to have your soil line. And if you're planting of a tree in a container, then I always recommend don't plant any deeper than the soil line that exists in the container when you purchase it.
Farmer Fred 26:01
Garden Basics comes out every Tuesday and Friday and it's available just about anywhere podcasts are handed out. And that includes Apple podcasts, I Heart Radio, Spotify, Stitcher, Overcast, Podcast Addict, CastBox and Google podcasts. And for Northern California gardeners, check out this podcast: the Green Acres Garden Podcast with Farmer Fred, also available wherever you get your podcasts. Thank you for listening, subscribing and leaving comments. We appreciate it.
