(bright music) (mellow guitar music) - One of the areas that I get asked many questions about is pruning plants.

Many people are scared to prune for fear of killing their plants.

Now, those of you who are regular viewers of "Prairie Yard & Garden" may remember that my husband Tom and I have some discussions when it comes to plants in our yard and their care, especially pruning.

I'm Mary Holm, and come along as we all learn how and when to prune our shrubs to keep them looking their very best.

- [Announcer] Funding for "Prairie Yard & Garden" is provided by Heartland Motor Company, providing service to Minnesota and the Dakotas for over 30 years in the heart of truck country.

Heartland Motor Company, we have your best interest at heart.

Farmers Mutual Telephone Company and Federated Telephone Cooperative proud to be powering Acira, pioneers in bringing state-of-the-art technology to our rural communities.

Mark and Margaret Yackel-Juleen in honor of Shalom Hill Farm, a nonprofit, rural education retreat center in a beautiful prairie setting near Windom, Minnesota.

And by Friends of Prairie Yard & Garden, a community of supporters like you, who engage in the long-term growth of the series.

To become a friend of "Prairie Yard & Garden," visit pioneer.org/pyg.

(uplifting music) - Years ago, we found out that planting a tree is as easy as one, two, three.

Then we found out four, five, six, how to care for trees so we don't have to pick up dead sticks.

Last year, we had seven, eight, nine.

Pruning trees to keep them growing and looking fine.

And this year we have Gary Johnson from the University of Minnesota back for 10, 11, 12, keeping our shrubs on the good-looking shelf.

Welcome Gary.

- Well, thank you.

It's always good to be back in Morris.

I would like to point out one thing, that if you look back on the previous shoots that we've done, every time I come here, I bring beautiful weather.

- [Mary] (laughs) Thank you very, very much too.

- You're welcome.

You're welcome.

- Gary, one of the questions I get a lot is, how do you prune shrubs?

And so I wanted to ask, is it important to prune shrubs?

- That's one of those questions that you answer with, "Well, it depends."

First of all, if the shrubs are getting leggy, if you've planted those shrubs to create a visual barrier between you and your neighbor or the highway, and they've gotten older and leggy, which means they lose their lower foliage, that's good reason to prune.

You gotta bring them back down again so you can encourage that lower growth.

That's a good one.

If they've been broken, especially like with evergreens.

They get broken by heavy snows or ice loads, or any type of broken branch.

That's a good reason to prune too.

If they're a plant like red osier dogwood that you value for the bright red twigs, as they get older, those bright red twigs get kind of gray and mottled looking.

And so you want to encourage that newer, younger growth again.

And then on some plants, the ones that you really value for flowering, they usually flower better on their younger to middle age type plants.

So as they get older, sometimes the flowering kind of fades away a bit.

Then the other reason is for shaping, and there's a term called topiary.

And I think everyone thinks that, "Oh, that's for fancy gardens or European gardens."

It's like, "No."

When people shear their hedges, whether they're round or squared off, that's topiary.

And so if people want to control the size or shape, that's another good reason to prune.

- [Mary] Is it better to shape the plants or sometimes buy a plant that stays smaller for a spot?

Tell me what your opinion is on that.

- [Gary] If you do have a very small garden or a small planting space, absolutely.

Buy the appropriate plant for it.

Almost every shrub comes in either a full-size, and then you have compact, and then you have dwarf.. - [Mary] Is there a best time to prune?

- Again, it all depends.

If you have some of the hydrangeas that flower early in the in the growing season, like before the middle of June, those you prune about a week or so after they're done flowering.

If you have autumn flowering plants, like summersweet or witch hazel or althea, then those you prune early in the spring, March, early April.

If you have evergreens and you're gonna shear them, I highly recommend you prune in roughly April, you shape them in April.

Because if you mess up when you're shaping them, cutting them little bit too far, which you're going to, by the end of May, early June, they put on the new growth, and they've kind of covered up your sins on that.

So a lot of it depends on the time of the year.

- So it's really pretty important that you know what you have in your yard or what you have planted in order to time your pruning.

- Oh absolutely.

It's not like the end of the world.

It's not like you're gonna kill them, but you could completely lose a season of flowers.

- All right, when it comes to pruning, let's talk about a group, and I would call them foliage scrubs.

- One of our native shrubs is ninebark.

It's one of those I call a junkyard dog.

If you kill a ninebark, you had to have tried to kill it.

(Mary laughs) They grow just about anywhere.

This is one of the kind of later varieties of it.

And it's an ornamental variety called little devil.

There are other plants, Clavey's honeysuckle.

This one does, Clavey's does have a flower to it.

It's a nice little flower, but again, most of the time, people plant this because they want a low hedge.

They want something to block the view.

And it does have this kind of almost a silvery green foliage to it.

So yes, they have flowers.

We don't plant them because of their flowers.

We plant them because of their leaves, the color of the leaves, the density of the leaves.

- [Mary] So since we don't have to worry about flowering, when is a good time to prune these guys?

- [Gary] Anytime your pruner is sharp.

The big thing about any shrub, almost all shrubs grow by canes, which are multiple stems.

And that really helps you determine how you're gonna prune them, I should say.

- [Mary] Gary, how about flowering shrubs?

- Well, if the shrubs flower before the middle of June, that means their flower buds were set on growth from last year.

So when they're done flowering in about a week or so, then you do your pruning, and that will allow them to put on new growth, new flower buds, and they'll flower normally next year.

If they flower in late summer, then you prune those early in the spring, because they set their flower buds on that new growth early in the spring.

This is gonna sound almost contradictory to what I said earlier.

The viburnums, they have a nice flower to them.

Normally, people don't plant them for their flower.

They plant them for the fruit.

Viburnums like this, they have a pretty good size dark blueberry that the birds love.

And then their autumn color is a burgundy.

It's absolutely beautiful.

This is a before June flowering plant.

So this is one that if you wanted to prune it and still have flowers next year, if you really value the flowers, you would wait till it was done flowering and then prune it.

However, I plant them because I like the fruit for the birds.

So I don't even prune them afterwards.

I wait until the birds have basically cleaned off, and I don't put them on a regular pruning cycle.

Hydrangea is a little bit different.

First of all, there are a lot of different hydrangeas.

And some of them flower on current year's wood.

So you absolutely have to know what variety of hydrangea you have, and you need to know, are they early flowering or later flowering?

Do they flower on last year's wood, or do they flower on current year's wood?

- Well, you said that you'd be willing to actually show us how to do some pruning.

- More than glad to.

A really good rule of thumb on pruning hydrangeas is if you don't know what kind of hydrangea you have, don't prune it.

Unless it's getting really too leggy or too big, or you have deadwood.

So one of the things you can do safely without the, "Oh, am I gonna ruin this?

Am I gonna ruin the flowers?"

No, you never get flowers off deadwood.

So you can just prune off the deadwood.

And it kind of cleans it up a little bit.

There's a broken branch, clean it up, get out the deadwood, and no harm done.

And you've actually kind of made it look a little bit nicer too.

Obviously, if I prune any off here, I'm gonna lose the flower.

So I would just let it go.

And like we said earlier, if you don't like the floppiness of it, you can just give it a little bit of artificial support.

- [Mary] Okay.

- Yeah, hydrangeas are a little bit of a challenge for pruning.

I'm gonna go back to this viburnum, and there's another type of pruning, and it's called renewal pruning.

Renewal pruning, we use this a lot on lilacs, old forsythia, old honeysuckle, old, old red osier dogwood.

And we go in and we remove the canes that are thicker, older, and are blocking out sunlight to the base of the plant.

So in this one, even though it's a fairly young plant, I have to demonstrate on something, I'm gonna prune these back.

Gonna pick out one or two of the older canes, and I'm gonna prune them right back almost as close as I can to the ground.

And that's good enough.

Now what's gonna happen on these, two things happen.

One is you have really good sunlight now penetrating down here.

The more sunlight you get down in there, there are buds in there, and they'll sprout.

By going through and just selectively.

Maybe do this, take out one or two of the stems every year for three or four years in a row.

And eventually, you're gonna have a nice full plant again, but it takes three or four years in a row.

Could you hand me that ninebark?

- [Mary] Oh, you bet.

- So this one is very, very healthy.

Like I told you, ninebarks are junkyard dogs.

And so the opposite of a renewal pruning is a rejuvenation pruning.

Just prune it as close as you can to the ground.

And this is gonna sprout up.

If we planted this in the ground today, this would be back up to that size probably by mid August.

So it's a way of rejuvenating a plant.

So renewing, you're just kind of slightly taking out the older ones, gradually a little bit.

And rejuvenating, just cut them right back.

The more canes they have, the faster growing they are, the healthier they are.

I always recommend rejuvenation pruning.

Now, looking at the two methods, if your spouse trusts you, I would use this tactic.

If your spouse doesn't trust you, then I would use the renewal tactic, where you're just taking out a little bit at a time.

'Cause it's less of a shock that way.

- Should you water the shrubs after you prune like this?

- I would water them before I prune.

If you figure you want to prune them back, maybe for a week or two before you do that, start irrigating them, make sure they're healthy.

After you prune them, absolutely, keep them well-watered.

Could you hand me that viburnum, please?

- [Mary] You bet.

- There are more species and varieties of viburnum than any other flowering shrub.

So first thing I'm gonna do, just 'cause I must have done this when I transported it, broke a couple branches, and I'm gonna prune those off.

But the reason I want you to look at that versus Arrowwood viburnum.

What I hope you notice is there's one stem.

This has one, two, three, four, five, six, seven.

So this has multiple canes.

That has one.

This is one you can actually prune into a tree.

This is a Viburnum lantana.

You can actually prune this into a tree if you want to, because it grows so well single stemmed.

But that's also how you normally prune it too.

It's like, "All right if I cut it back to the ground, holy buckets, that could be quite a shock on this, on a single stem one.

Maybe what I'll do on this one instead of renewal or rejuvenation, I'll say, "Well I'm gonna do a little bit of thinning pruning."

So in this one, I'm just gonna give it a little bit of shape and keep the central part as the main leader and just kind of shape it a little bit just because I want to.

I don't need to.

Quite honestly, for a good portion of their life, most shrubs don't need a whole lot of pruning.

But if I just want to do a little bit of sides or shape control, I would just thin it like this, and then call that good enough.

This one I would not cut back to the ground, because it is single stemmed.

This is potentilla.

So we throw out all the rules with potentilla.

I'm gonna cut this back, and I can guarantee you, I'll plant this out at our nursery, and you can see it's flowering now.

I've never, I'll have to be honest with you, I'm kind of sick of potentilla because they were so over planted for so many years.

But one of the things I really like about them is I'll plant this out.

It'll just sprout like crazy, and it'll flower.

- The same season?

- The same season.

And I can let this come up, let it flower, cut it back again.

It'll put up new growth, flower again.

They repeat flowering off of current year's wood.

And I mentioned earlier, Japanese spirea is the same way.

So in those, if you like the flowers, shoot, it doesn't matter when you prune, because they're gonna put out new growth.

They will flower.

Now we'll look at a couple of evergreens here, and this is mugo pine.

And if you're gonna, the reason why people prune mugo pines is, "Oh they're getting too big."

Now, this is a dwarf one, so I don't really need to do it.

But if you are roughly, what are we now, the end of June?

In another week or two, you can go through and you can snip back these candles, just like this, and candles don't have any, they don't have nodes.

They don't have buds on them like a spruce would or juniper or something like that.

So you can just prune them back, and this will get them to get even more bushy if that's what you want, but it's a way of controlling their size.

So you do this late June to mid July.

If you prune earlier than that, it kind of kills the candle a little bit.

It doesn't kill the shrub, but you'll get some browning in that.

And if you go late in the season, then the needles kind of turn brownish.

This way by pruning it here, these needles haven't fully expanded, and they'll cover up any browning or any empty spot in there.

But before we leave evergreens, and actually a different type of pruning, I'm gonna look at kind of another size control tactic, and then a way of shaping plants too.

When you look at all the evergreens that we can grow in Minnesota, we have Japanese yews.

Japanese yews are the easiest ones to work with because you can literally cut a Japanese yew back to a few inches from the ground, and they have all these dormant buds that'll sprout right up.

The opposite end of the spectrum we'll look at are junipers.

And once they get shaded out in the center, the buds die, and you pretty much have a dead looking plant.

In the middle are arborvitae, or northern white cedar.

So this is one of the globe arborvitae.

And one of the rules of thumb with arborvitae in terms of pruning is you can shear them.

You can reduce their size by as much as 20% at any one time.

So it's kind of nice if you selected the wrong variety, and it's gotten too big for you, or it's blocking a window or something.

You can start bringing them back.

And one of the ways you can bring them back is you can shear them back.

So on this one, it's just typical head shears, you can take off 20% of the size both in height, and I'm gonna use the hand shears for this, get that off, both in the height and the spread.

And you're looking at this and thinking, "Oh my gosh, it's taken off an awful lot."

They'll recover from this beautifully.

That's one of the nice things about arborvitae is they do have that ability to recover from shearing like this.

And, again, the only reason I would do this is if, oops, I planted the wrong one in the wrong spot, and it's getting way too big for the area.

So once I do this, though, one of the keys to keeping an evergreen really nice and healthy is making sure that enough sunlight gets down in there.

So those interior buds and interior foliage stays nice and green.

So once I reduce the size like this, then I just kind of randomly go through and open up little pockets of sunlight.

You can do this again next year.

It's gonna grow back more, and you can bring it right back down to this size again next year.

Again, with junipers this is a variety of Chinese juniper, which is the most common landscape juniper.

And people like to shape these too.

So they'll shape into mounds or square them off, or put them in hedges, which is, there's nothing at all wrong doing that.

And you can do it with the shears, or you can do it with your hand pruners.

(shears click) Start it off, and then you say, "Okay, now I want it to be a little bit more rounded.

So I'll kind of finish it off."

And there's really nothing wrong with doing this.

The problem is, each year when you do this, it develops this green crust, and it gets thicker and thicker and thicker foliage.

And the interior foliage, the interior buds, they die, turn brown and then die.

So the trick to being able to reshape a juniper or keep it smaller is once you shear it or prune it back, is, again, you go through, you open it up so you get plenty of sunlight penetrating all the way into the center of that.

And this way, you can shear, you can have topiary junipers for a long, long, healthy life, because you're allowing more sunlight to reach into the center.

And that'll green up from the center of them too.

So this is the last one, deciduous.

We're back to the Clavey's honeysuckle.

And again, we can go a little bit of topiary on this.

If we want to plant these and trim it into a hedge.

So this is approximately the height of the hedge that I would like to keep it at.

The whole thing about hedge pruning is, again, sunlight.

And the base of the plant should always be broader than the top part.

So you never square it off straight up or round it straight up.

Because what'll happen is you don't get enough sunlight to the lower branches.

And then the leaves, the buds die, and it gets leggy.

And then, what are you gonna have to do?

You're gonna have to cut it all the way back to the ground, start over again.

So I'll give it a little bit of a shaping.

This'll be kind of a rounded head shape.

Just imagine a whole bunch of these in a row.

This is a good, healthy shape now for it.

And again, the last thing I'll do is just go through again.

Do a little bit of selective pruning to open up sunlight in there.

It's all started off now.

It's got a little bit of a shape to it.

It's got plenty of sunlight penetrating in there so we'll keep the foliage good and healthy.

And we're good to go.

- Gary, as long as you're here, I have a couple of plants that need pruning.

Would you help?

- Absolutely.

Let's go do it.

(laid back music) - I have a question.

How can I tell when apples are ripe for picking?

- Well, I think the thing that we look as apple researchers is something that a consumer may not think about always.

So for most people, they would consider the redness of the apple to determine the ripeness.

But in fact, the redness is actually a fairly poor measure of ripeness.

Redness actually just means that the fruit has been exposed to the sun.

So you'll see the fruit here that's exposed to the sun is turning nice and red.

You see the fruit inside is not so red.

So there's really not that much difference in maturity, but appearance-wise, there is.

So when we are trying to determine the ripeness of an apple, what we look for is the background color of an apple.

And the background color is basically the part of the fruit that's not red.

And so sometimes you'll have to turn the fruit around.

Some fruit will be 99% red, and it's hard to find that background color.

But when you do find that background color, what you'd like to see is a more of a yellowish green.

And in fact, the more yellow, the more ripe it is.

Now, let me just give you an example of an apple here.

This is a variety called Paula Red that's grown throughout the Upper Midwest.

This turns red probably three to four weeks before it's actually mature.

So if you were to look at that fruit, either in the market or on your tree, you'd say, "Oh, well, they're completely ready."

By turning that fruit around, you see how bright green that is.

So that fruit is probably still a week or 10 days away from maturity.

While this one, another variety, State Fair, is completely ready.

This tree behind me is Zestar!

Apple, one of our best early season apples that we have in Minnesota.

And you can see, again, the fruit looks fairly ready on the surface, but if we pick that, you can see that there's still quite a bit of green behind that.

So it's not that this fruit can't be eaten, but it is immature, and it won't have the sugars and the full flavors that the fully ripened fruit would.

- [Announcer] Ask the Arboretum Experts has been brought to you by the Minnesota Landscape Arboretum in Chaska, dedicated to enriching lives through the appreciation and knowledge of plants.

- Gary, here is a potentilla that needs some help.

- Yep, well, there is some deadwood in there that needs to come out.

It's a little rangy looking.

I would recommend that I rejuvenate it.

Basically, cut it back to the ground.

Do you trust me?

- Oh, absolutely.

Go for it.

- Okay, good.

Most of the time when I'm rejuvenating, I like using these long-handled loppers, mostly because I don't like bending, and this allows me to get right down in there to start pulling it out.

So if you look down in here, you can still see there are buds in there, right in here.

Now that they have sunlight, they'll grow and fill in real fast.

And by the end of the summer, this thing will look beautiful again.

And it'll be flowering again too.

'Cause they flower on current year wood.

- [Mary] Here is a lilac tree that has really kind of overgrown its area.

What should we do?

- Well, looking at it, it's pretty darn healthy.

But if you look to the interior, you have a lot of the canes that are getting pretty big.

And I think if we, versus the rejuvenation pruning we did on the potentilla, we're just gonna do a little bit of selective renewal pruning on this.

And I'm just gonna cut out a couple of those larger canes so sunlight can get in there and start filling this lower part in with shorter but nice full green foliage in there.

And I could do it with one of three pieces of equipment.

I can use loppers again.

And so for instance, we can take this part off.

We've opened up some sunlight there.

Thank you.

If you have a really, really big and it's a really overgrown hedge, I like using pole saws.

'Cause you can just kind of work your way in there and find the branch you want to cut out and saw it off without having to get all the way to the interior.

And some of the shrubs are kind of spiny or spiky.

That's why I really like using these.

The other is you can just use a basic folding saw like this.

And this is a Corona, a really good saw blade.

They have the tri-cut blades on.

Most pruning saws now, if you look down at the blade, you'll have teeth going this way, and they're just razor sharp, and it makes it so nice to saw through.

So I'll use these on one.

I'll use the saw on one or the other canes, and I'll take them.

I'll take this one off.

So that's opened up, that's opened up lots of light in there now.

And so there's tons of buds in there and small leaves, branches.

So those'll green up faster and grow fast and fill that in.

This is what I call pruning that's more acceptable to spouses.

Because you're only taking off a little bit each year, a little bit at a time, and it just slowly renews the plant versus cutting it all the way back.

(mellow guitar music) - Thank you so much, Gary, for coming out and teaching us all about pruning shrubs.

- Oh, you're welcome.

I love doing this kind of work, and I love coming to Morris.

So you are welcome.

- [Announcer] Funding for "Prairie Yard & Garden" is provided by Heartland Motor Company, providing service to Minnesota and the Dakotas for over 30 years in the heart of truck country.

Heartland Motor Company, we have your best interest at heart.

Farmers Mutual Telephone Company and Federated Telephone Cooperative, proud to be powering Acira, pioneers in bringing state-of-the-art technology to our rural communities.

Mark and Margaret Yackel-Juleen in honor of Shalom Hill Farm, a nonprofit rural education retreat center in a beautiful prairie setting near Windom, Minnesota.

The Minnesota Arts & Cultural Heritage Fund, with money from the vote of the people of Minnesota on November 4th, 2008.

And by Friends of Prairie Yard & Garden, a community of supporters like you who engage in the longterm growth of the series.

To become a friend of "Prairie Yard & Garden," visit pioneer.org/pyg.

(bright music)