Hardy Cactus

Hardy Cactus

Part of Ep. 1905 Water Conservation

Wisconsin has its own native cactus, prickly pear cactus but there are others that are hardy here as well.  Cacti and succulent grower Dan Mahr shows off his collection of of both hardy and non-hardy cacti and tests Shelley on her cactus knowledge.

Premiere date: Jul 06, 2011

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley Ryan:

You're looking at prickly pear cactus. It is the only hardy native cactus. And yes, it's native to Wisconsin. I am with cactus hobbyist Dan Mahr in your home near Sun Prairie. Dan, this isn't the only cactus you grow here.

 

Dan Mahr:

No, prickly pears, there are several prickly pears which are hardy, because they come from the northern tier of the United States, and even up into southern Canada. But there are a few other type of cacti which, although they don't grow here naturally, they do survive our winters. And again, they're from northern areas, so anywhere from the Dakotas across Colorado and even up into Washington state, there are cacti which we can grow here in Wisconsin.

 

Shelley Ryan:

You know this because you've been growing cactus for how long?

 

Dan Mahr:

Way too long, over 50 years.

 

Shelley Ryan:

So hardy ones, and also inside a greenhouse. I mean, if it's cactus, you go after it.

 

Dan Mahr:

That's right. I grow many different types of succulent plants, just a few cacti. The ones out in the garden are very nice because just in a couple weeks these are going to be in beautiful bloom, yellow and purple and pink flowers on them.

 

Shelley Ryan:

Prickly pear is the only one native to Wisconsin?

 

Dan Mahr:

We have three species of native prickly pear here in Wisconsin.

 

Shelley Ryan:

But it's all prickly pear.

 

Dan Mahr:

That's right. It's all prickly pear. The other hardy cacti, most of them occur further to the west.

 

Shelley Ryan:

Let's talk about some of the other ones then that we could grow in the garden in addition to the prickly pear. We've got one right here by my feet. I'm not going to touch this, but what is this one?

 

Dan Mahr:

This is one of several species which are called Hedgehog Cacti--

 

Shelley Ryan:

Very cute.

 

Dan Mahr:

Because they're spiny. This will have big purple flowers on it. In fact, there's a bud coming so in another few weeks, it will be in full bloom.

 

Shelley Ryan:

Most of these are spring bloomers?

 

Dan Mahr:

Most of them are spring bloomers, yes.

 

Shelley Ryan:

They really add color to the garden in the spring, too.

 

Dan Mahr:

That's right.

 

Shelley Ryan:

You've got a couple behind you as well.

 

Dan Mahr:

Yes, there's a couple over here that we call pincushion types of cacti.

 

Shelley Ryan:

I love the pattern on that.

 

Dan Mahr:

These stay small. They will gradually increase in size, and they will put little offsets around the edges, or extra little stems, so they'll gradually cluster. They also have flowers coming. These are both in bud as well, so they'll be blooming with little pink or purple flowers.

 

Shelley Ryan:

These seriously can handle Wisconsin winters?

 

Dan Mahr:

Yes, these have been in the ground here for several years. We do nothing unusual to protect them other than they are in a very rocky, gravelly soil, which provides good moisture drainage for them.

 

Shelley Ryan:

Okay, plant in rocks, good drainage. Do we have to worry about buying the wrong thing? I mean, do these look like something that's not hardy?

 

Dan Mahr:

Yes, that's a very good point. There are only some species which are really hardy here, so you have to be careful. Some of our better garden centers actually do carry a selection of hardy cacti and other hardy succulents.

 

Shelley Ryan:

So, buy the ones with the name that we're showing on the screen for these. Don't buy something else.

 

Dan Mahr:

That's right, because they won't survive here.

 

Shelley Ryan:

Okay, looking at all of these varieties just right here, and then the ones that you grow in the greenhouse, what actually constitutes a cactus? What's a cactus?

 

Dan Mahr:

That's a really good question. The term cactus refers to a particular family of plants called the cactus family, Cactacae. It's one of about 60 different families that constitute succulent plants. I've got a test put together for you, Shelley, to see just how well you can tell a cactus plant from another type of succulent. You want to go take that?

 

Shelley Ryan:

Let's see if I'm smarter than a 5th grader. These are all your tender collection, right, Dan?

 

Dan Mahr:

That's right. These are all non-hardy plants. These have to be protected from cold weather so they spend the wintertime indoors.

 

Shelley Ryan:

So, how does my test go?

 

Dan Mahr:

The first thing I want you to do is let me know what you think designates a cactus or signifies what a cactus is.

 

Shelley Ryan:

Well, without 50 years of background in this I think spines and no leaves.

Dan Mahr:

Spines and no leaves. Okay, why don't you point to the ones that you think are real cactus.

 

Shelley Ryan:

Well, this one for sure. In fact it looks a lot like a prickly pear cactus we just saw.

 

Dan Mahr:

Okay.

 

Shelley Ryan:

This one also kind of looks like the cactus we saw in your back yard.

 

Dan Mahr:

Okay.

 

Shelley Ryan:

Now, it's a stretch, but this one to me has spines and no leaves, so I think this is a cactus, too.

 

Dan Mahr:

Okay.

 

Shelley Ryan:

How did I do?

 

Dan Mahr:

Well, you did kind of okay. You got two right. Let's just go around the table. We'll start here with the first one that you picked out.

 

Shelley Ryan:

Okay, this one.

 

Dan Mahr:

And this is indeed a prickly pear cactus.

 

Shelley Ryan:

Oh, cool.

 

Dan Mahr:

It's not a hardy one, but it's a prickly pear cactus. It comes from South America.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

You were good on that. That is a true cactus.

Shelley Ryan:

See, I knew that.

 

Dan Mahr:

Okay. Now you said a plant that has spines but no leaves, which would rule out the next plant.

 

Shelley Ryan:

Yeah.

 

Dan Mahr:

Because even though it does have spines, it does have leaves on it. You're right there as well. This is actually in the Euphorbia family.

 

Shelley Ryan:

Really?

 

Dan Mahr:

This is actually very closely related to our poinsettia. It looks nothing like it, but that's what it is. It's from Africa, as well.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

The next little plant down here actually has spines on the leaves.

 

Shelley Ryan:

I'm not touching that one!

 

Dan Mahr:

That's an aloe, so that would be related to our aloe vera, our medicinal aloe, for example.

 

Shelley Ryan:

So, not a cactus.

 

Dan Mahr:

Not a cactus. That comes from Madagascar.

 

Shelley Ryan:

Okay, so far, so good, sorta.

 

Dan Mahr:

This one we would rule out also, even though it does have little spines on it, it's got leaves on it.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

This is actually really a cactus.

 

Shelley Ryan:

Oh, rats!

 

Dan Mahr:

There are some cacti that have really good leaves on them.

 

Shelley Ryan:

Really?

 

Dan Mahr:

Yes.

 

Shelley Ryan:

Okay, so what is this?

 

Dan Mahr:

It actually will grow into a small tree or a big shrub and it's from South America. In just a minute we'll talk about what actually constitutes a cactus, and then we'll be able to point out why that is actually a cactus.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

But that's a cactus, a true cactus.

 

Shelley Ryan:

Okay, with leaves. I was wrong.

 

Dan Mahr:

Then the next one has leaves and spines, but it's not a cactus.

 

Shelley Ryan:

Okay, so my theory is totally not.

 

Dan Mahr:

You're theory works for this one, because it does have leaves. But your theory is not universal is what we're getting at.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

You were right on this one. In fact, this looks very similar to some of the ones out in the garden. And this is a South American cactus. It is a true cactus.

 

Shelley Ryan:

This is the one I was wrong on?

 

Dan Mahr:

This is the one you were wrong on. This is actually another Euphorbia.

 

Shelley Ryan:

Really?

 

Dan Mahr:

It's very closely related to poinsettia. What tips us off here is the flower. You can see the little tiny bright yellow flowers. These flowers are totally unlike any type of cactus flower. All right?

 

Shelley Ryan:

Okay.

 

Dan Mahr:

But, spines, no leaves, so you would think it would be a cactus.

 

Shelley Ryan:

Yeah, that was my theory at least.

 

Dan Mahr:

Here we come to our fourth cactus. This is a true cactus. This thing that looks like green strings is actually a true cactus.

 

Shelley Ryan:

Does it have spines?

 

Dan Mahr:

It has very tiny rudimentary spines. That's part of the definition of a cactus. We'll come back to this, but this actually occurs in the rain forest of South America.

 

Shelley Ryan:

Oh, this is beautiful.

 

Dan Mahr:

The one in the middle of the table that looks kind of like an artichoke is an agave. It's in the century plant family. Again it does have spines, but the spines are on the succulent leaves similar to the aloe that we talked about earlier.

 

Shelley Ryan:

So, these are all succulents.

 

Dan Mahr:

These are all succulent plants, but only four of them are cacti. Let's talk about what specifically makes a cactus.

 

Shelley Ryan:

Okay.

 

Dan Mahr:

If you look at the prickly pear, and you notice where the spines come out, you'll notice that there's like a little tiny pad of felt on the stem.

 

Shelley Ryan:

Like that little node there.

 

Dan Mahr:

That's called an aeriole. And only members of the cactus family have that. No other plants have that. That's one of the things that designates a cactus as a cactus.

 

Shelley Ryan:

Even if I go to this thing with a magnifying glass, somewhere I'm going to see that aeriole?

 

Dan Mahr:

That's right. They're very, very tiny on here, but they are there. In fact you can see very tiny little spines associated with them.

 

Shelley Ryan:

Very interesting.

 

Dan Mahr:

So, that's what distinguishes cactus. That and there's one other thing. The cactus have a particular type of pigment. One of the purply pigments that most other plants do not have. So that's kind of a biochemical way that distinguishes a cactus, also.

 

Shelley Ryan:

Well, regardless, I think I'm going to have to try to grow some of these only with gloves on. All right. So, thank you very much, that's very interesting.

 

Dan Mahr:

Very good, Shelley.

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