Caterpillar Observations with Master Gardener Pat Concessi

Hi, welcome to The Garden Shift.

In this episode, my guest, Toronto Master Gardener and Toronto Nature Steward, Pat Concessi, joins us to talk about caterpillar observations in her garden. We also discuss chickadees, moths, and more.

I hope you enjoy.

Tina: Hi, Pat, it's Tina. Great for you to join today.

It's so funny because I'm getting calls from people about something's eating my plant. Help. Is it good? Is it bad? Am I in trouble? Should I do something about it? I think the latest one was from my sister. She identified the same thing that you and I were talking about. So let's talk about the parsley caterpillar.

Pat: Yeah, you know, I've had caterpillars on two parsley plants in two different gardens.

I think when I was talking to you, I sent you a picture of the black swallowtail caterpillar on the parsley plant in my backyard. And we put parsley on our meals just because it's there. But when I look really carefully, it may be that the caterpillar ate as much of that plant as we did.

And really, to tell you the truth, I grow it for the butterflies. I remember Paul Zamet saying years ago that he tucked it into containers just for the swallowtails. So ever since then, I've always had a parsley plant in a big clay pot.

And I noticed it when I was watering one day. But a couple of days later, I was down at the school because, you know, with the teachers away, I do the weeding in the herb garden there. And I pulled out a pretty good size ragweed plant.

And there were two caterpillars on that parsley. And one of them was the size that you think of as sort of being full grown. So a couple of inches long and as big around as a marker. But the other one was half the size and really thin.

Tina: On the same plant?

Pat: Yes, yes, they were on the same plant. And they were actually on the side that had been adjacent to the ragweed. Because when I got in the car and went home, I thought, oh my goodness, I wonder if that ragweed was keeping the birds from seeing it.

Tina: Right.

Pat: But I wasn't going to leave the ragweed. But I wondered maybe if I put a wire mesh screen around it, that might protect it from the birds.

But I know what you're going to tell me next is it's all part of habitat and the birds need to eat too. But somehow, when you see somebody in the garden, you just get that really protective feeling about that one insect at that vulnerable stage of its life.

Tina: Yeah, it's interesting too about how we have to stop and observe our gardens, right? Actually, actually like just be in our gardens, not walking through it and rushing to water, walking through it and pulling out a weed. I think being in the garden allows you to really understand why your backyard is so important, right?

Pat: Yes, because parsley is a wonderful plant, but it's not native. And so I looked in Rick Gray and Sean Booth's book that I'm always raving about, Gardener's Guide to Native Plants of the Southern Great Lakes Region.

When I look in that book and say what plant is host to the black swallowtail, it's Zizia aurea, golden alexander. So I planted mine in the front yard and I couldn't tell you whether there were black swallowtails on it because it's out near the curb. You know, it's underneath my Sumax there. I don't spend any time sitting there watching it.

And I feel like I know what's happening with the plants that are where I sit and have coffee in the morning, where I sit in the shade later in the day. So you're so right. We need to put the phone away and just sit and watch the garden.

Tina: Yeah, I have a hard time putting my phone away because I'm afraid I'm going to miss something that I need to capture on my phone. But I think the idea of having your lawn chair move around the garden for you to sit beside some of your favorite plants.

You know, the other thing that occurred to me during COVID, it probably occurred to you well before this because you've been a birder for longer than me, is how important it is to have caterpillar food for our birds.

And if we don't have caterpillars, we're not going to be feeding all of these fledglings. And, you know, they need those proteins. They need those fats, right? So I think we have to help people to understand the importance of these caterpillars for people who love to see birds in their garden.

Pat: And to celebrate the fact that we see an oak tree and its leaves have been eaten. That's a good thing. There's a caterpillar who had breakfast, lunch and dinner in that oak tree. For as much as, when I look in my garden, I'm usually looking down and I'm rarely looking up.

But sometimes when I walk around the park across the road, I do look up at the oak trees to see how the leaves are doing and whether there are caterpillars in there.

Tina: Yeah, and I love that study. Can you speak to that study that Doug Tallamy, the entomologist from Delaware, did about the chickadees and the shocking amount of caterpillars they need for their fledglings?

Pat: Yeah. Now, you put me on the spot and I can't remember, but I think it's six or seven thousand caterpillars. And I see the chickadees constantly coming back and forth to my shelled sunflower.

But that must be just to keep their own energy level up, because Tallamy says they feed the babies caterpillars because they're soft and mushy. I'm hopeful that they're finding caterpillars they need to feed their babies and then coming to eat the seed just to get the protein and the energy that they need to keep themselves going.

Tina: Yeah. And then that other thing is people say, oh, there's a huge field across the street or there's tons of agricultural land they can go to. But again, Tallamy, our favorite entomologist, says that they're just not going to fly that far. I mean, once they have those babies, they need them close by, right? So no, they're not going to go flying over miles to go look for caterpillars.

Pat: Well, not with the hawks that live in my neighbourhood.

And we tend to think of our ravines as being full of goldenrod and asters and all those keystone plants that Tallamy talks about. But I'll tell you, from my time stewarding in the ravine close to me, those plants just aren't there. The parks tend to be either mowed grass or mature forest.

So those plants that would grow on the verge, the goldenrods and the asters and rudbeckias, they're just, you rarely see blooming plants when you're walking in our natural areas.

Tina: Yeah, that's just so depressing. And then when you do see, you know, a carpet of something, it's something invasive, like periwinkle, that's taking the place of what should be an ecologically important plant or significant plant, right? So we'll have another episode on invasives and you can talk about that with your ravines.

Pat: Well, when you mentioned carpet of flower, what comes to mind is the scilla, the blue bulb in the spring, which really keeps the native ephemeral plants from getting started, and the lily of the valley.

Tina, before we forget it on birds and their dependence on plants, my cardinal flower is looking beautiful and the hummingbird has been here to visit again this year.

I don't know how large its range is because I see it very infrequently, but when it is there, it's back and forth horizontally in and out of those trumpet shaped flowers on the cardinal plant.

Tina: I don't know if this season is just different or if I'm more aware, but there just seems to be a lot of hummingbirds around in my garden and my friend's gardens. Definitely drawn to trumpet shaped flowers and colour, right? Red specifically?

Pat: I don't think I've ever seen a hummingbird on my great blue lobelia, which has, well, it isn't trumpet shape. It's sort of the same spike with flowers on it, but the one that they reliably visit is that cardinal flower.

Tina: And you didn't have any trouble getting that cardinal flower established?

Pat: Well, it was tricky because the rabbits or the groundhog loved it. And the first year they ate it and I put, you know how I make a cylindrical tube out of hardware screening? That stuff that I buy at the hardware store and the grid is about a little bit less than a square centimetre. And I put a tube of it over and that little plant came back from its roots.

The first year it was a really tall spike and it bloomed beautifully. The second year, not so much, but it's back this year and there are seedlings around it this year. And of course I collected seed from it and I grew some of them. So I've got it scattered around the yard.

Tina: Okay. Well, listen, Pat, I would love you to come back and talk about seed collecting with us because I know we're getting close to that time. When would be a good time to really start looking and collect these seeds in your garden?

Pat: Well, I know you and I both collected our wild columbine because that seed matures early in the year. I think the next one up for me, I have some lion's leaf coreopsis that are brown.

I always say when the stem turns brown, the seed is mature. And it's usually about six to eight weeks from the end of the colour on the bloom to the seed being mature. So most of my plants are going to be another six to eight weeks.

Tina: So we should be, we should be collecting our Zizia, our wild, our columbine alexander, right? I think mine are pretty brown. I got to go have another look at them.

Pat: Yes. And the anise hyssop isn't far behind. So sometimes you'll have a long blooming perennial and you can be collecting seed from one seed head while others are still blooming.

Tina: Right. And that book that you mentioned that I got as a birthday gift, which I'm so excited about, Native Plants of the Southern Great Lakes Region, Rick Gray and Sean Booth has all the propagation and seed collection information, right? Listed?

Pat: Yeah.

Tina: As well as the host larval butterfly moth associations of each plant.

Pat: So it's just packed with information. It's the one book that you can take it out into the garden rather than needing to come in and get on the internet because all the information that you want as a native plant grower and propagator is in that book.

So many other books help you identify a plant in a garden, but they don't help you to grow that plant for your own garden.

Tina: Correct. Yeah. It's a great book. Pat, thanks for taking the time with me. Love talking to you.

Pat: Okay. Talk again, Tina.