- From the fungus-infested Univest Studios at Lehigh Valley Public Media in Bethlehem, P.A., it is time for another blighted episode of chemical-free horticultural hijinks, You Bet Your Garden.

Arborvitae seem to be turning brown all over town.

I'm your host, Mike McGrath.

And on today's show, I'll reveal what I've learned about arborvitae blight, and what you can do to stop it, or at least slow it down.

Plus, yes, we will take that heaping helping of your fabulous phone call questions, comments, tips, tricks, suggestions, and heartily harassing harrumph-ifications.

So keep your eyes and/or ears right here, cats and kittens, because it's all coming up faster than you turning those brown spots back to green right after this.

Support for You Bet Your Garden is provided by the Espoma company, offering a complete selection of natural organic plant foods and potting soils.

More information about Espoma and the Espoma natural gardening community can be found at... - Welcome to another thrilling episode of You Bet Your Garden, from the Univest Studios at Lehigh Valley Public Media in Bethlehem, P.A.

But I must acknowledge that my mind is in Philadelphia right now.

Now we're taping this show on Wednesday, I believe it's the 26th, and the World Series will not start until two days from now, on Friday.

And the Phillies' first home game will be on Halloween, which is always a lot of fun, which is why I'm not getting ahead of myself.

I don't want to throw a kinohara at the team, so I'm just wearing my National League pennant Phillies gear.

And hey, come on, kids, the pennant is something!

You get a ring, you know?

And Bobby, the bobble head is excited about the upcoming games, too, aren't you, Bobby?

Yes.

Once again, kids, I have lost it.

But I'll pull it together to take a couple of your fabulous phone calls at... Kirsten, welcome to You Bet Your Garden.

- Thank you.

Nice to be here.

- It's nice to have you here, how are you?

- I'm doing just fine.

I'm doing just fine.

I'm actually just outside Philadelphia.

So we are all experiencing and happy about the whole Phillies going to the World Series, and it's a really good vibe around here.

- Grease the poles!

So what can we do you for?

- So I am reaching out because we are redoing our landscaping on our suburban property, and I need to put in a hedge fence in my backyard because I'd really prefer greenery to a large wooden fence, and I'm struggling with what exactly to put in.

I had originally thought that I would do Skip Laurels, and we had somebody tell us that they're maybe starting to get some disease here and there.

We really have to treat them to stay on top of it.

And then, there was also a suggestion of California Privet and I had some concern with that as I saw that it was invasive potentially.

And so, I'm just struggling with what's the right hedge to put in, because we really do want privacy from our neighbors, and for our neighbors.

And so, I just really wanted to call in and get your advice on what you would recommend.

- Whenever you research invasive plants, it'll tell you this plant has been given the title of invasive in California, New Mexico, whatever.

But I don't believe there is any prohibition.

It's, you know, it's informative.

They're hoping gardeners will be good people and not buy invasive plants, and that nurseries will be good people and not sell invasive plants.

But there's no penalty.

And so, you know, without the rap on the knuckles with the sharp stick, people can probably just do what they want.

And I get complaints all the time of nurseries selling invasive plants.

Now, before we get to my recommendation, did you look up Skip Laurels and see if you could find any bulletins on disease?

- No, I could not.

I did go to the Google for that, and I was not able to find anything with regards to disease currently.

- I would want to research that further.

And you know what?

Why don't you just send an email to Penn State, to their extension service there?

They're the main extension office for all of Pennsylvania, and see what they say and search it at their website, because maybe it's having disease problems down south, but not in the Philadelphia area.

You know, Privet is one of these catch-all terms.

It's like boxwood.

You know, people don't know what to call it.

They call it a privet or a boxwood, or something like that.

So, Chinese privet is the worst.

It is the most invasive.

It should not be sold.

I mean, I'm going to agree with my frenemy Doug Ptolemy here, they should be cut down and destroyed.

They are nasty plants.

California privet, I mean, that's another slippery term, you know, but when you get down to named varieties, things become a little easier to research and be specific about it.

- That's really helpful.

Thank you very much.

- All right.

Good luck to you.

Kenneth, welcome to You Bet Your Garden.

- Thank you.

Thank you for taking my call.

- Well, thank you for making it, may I call you Ken?

- Please do.

- May I call you a cab?

- I answer to anything, especially when it comes from my wife.

- Right, right, just don't call me "late for dinner".

Well, how are you doing?

- I'm doing fine.

It's getting a little chilly.

I'm out in California.

I'm in Palo Alto, near San Francisco.

So, now we know who you are and where you are.

What do you need?

- Well, usually, I rake up all my leaves, and I put it over my vegetable beds during this time.

But lately, because of the drought, the leaves haven't been decomposing until about mid-summer.

So, when I put in my tomato plants, I'm digging a hole in the pile of leaves and planting it in there.

So this year, I thought maybe since we're going to have another drought, I would get a leaf shredder and maybe hasten the process.

So I was wondering, which kind would you recommend, and do you have a brand?

I could use any advice.

- I have... Well, first of all, we're in a whole new world.

There's no need for gasoline, and there's no need for long electrical cords.

My garden equipment is totally rechargeable cordless.

I have, I believe it's a GreenWorks leaf blower, with a reverse setting that shreds the leaves in a collection bag.

So no more bending over.

But before we continue with that, it is vitally important to shred your leaves, because whole leaves are going to prevent any water you get from getting into the soil successfully.

So when the leaves are shredded, they slow the rain down, but it all goes through very quickly.

And with whole leaves, you can get mold on the bottom if you have a rainy spell.

- Oh, okay.

- So, I mean, your head's in the right place.

I gave up on gasoline, like, the first year I gardened.

I felt like I was poisoning everything around me.

And these machines are much quieter.

Your neighbors aren't going to hunch their shoulders up and go, "Let me get my B.B.

gun, Ma!

"I'm going to teach that boy a lesson!"

So, everything about them is great.

I mean, they're great for the environment.

And again, because they're shredded as you suck them up and they go into a collection bag, there's almost no work involved.

And, you know, spend your time wisely, spread it out.

Every dry day you get, go out and, you know, shred a couple of bags, 2-3 bags.

And what you don't need for your garden beds, put them in a compost bin.

Shredded leaves alone make excellent compost.

And if you want to make even better compost and make it faster, you mix in spent coffee grounds with the leaves, mixing it as you go, and that will heat up the pile.

You'll be able to warm your hands over the top of that compost pile on those cold mornings.

- The only leaves that I have hesitation grinding up would be the magnolia leaves, because I heard they take a long time to decompose, if I shred it, would that be okay?

- Yes.

They're almost succulent, you know, they have a lot of moisture inside them.

So, the drier you can get them, the better.

And the old adage with this and black walnut leaves, and other, you know, kind of iffy things is don't make them a huge part of the compost, you know, or the leaves you suck up.

10-20% is fine, but you don't want to try to make a compost pile out of one type of leaf, if it's unusual, like yours.

- Terrific.

Thank you for all your help, I appreciate it.

- We appreciate your call.

Good luck now.

Linda, welcome to You Bet Your Garden.

- Thank you.

How are you today, Mike?

- I am just Ducky!

And I'm baseball-mad because my Phillies won the National League pennant.

And when this show airs, they'll be in the World Series.

As we say in Philly, grease the poles!

Where are you?

- I'm in Pennington, New Jersey.

- Okay.

You could be a Phillies fan.

- So my problem... - Yes, please.

- I have two beautiful trees.

They're probably about eight years old.

We planted them two years ago.

One is a red bud, and one is a dogwood.

And they're planted in a meadow kind of area of my backyard.

We only mow it every 2-3 years.

- Okay.

- And over this past winter, either mice or voles, or something decided to make camp at the bottom of the dogwood, and they chewed the bark about six inches up from the ground and made a complete ring all the way around the tree.

And I'm afraid it's lost.

- Well, you know that your meadow gives mice and voles excellent cover to get in there and nibble at the bark.

Did they touch the dogwood?

- No...they did the dogwood.

The redbud is still good, so I want to protect that over the winter.

I'm figuring I need to mow around it and then cut everything way back so there's nothing next to the trunk that is attractive.

But I didn't know if there was anything we could do to save the dogwood.

- Well, the first thing you want to do, I don't think the mowing is necessary because they're just going to hang out in the long grass and, you know, take a short walk over to your bark.

But you can buy at any nursery or garden center tree guards.

And there's many types.

When fruit trees, young fruit trees are sold, they almost always include a tree guard.

And one of the most interesting is it's just a long strip of white plastic that's continuous.

So it's really easy to wrap around the tree, but it's a deterrent.

Since this sounds like an out-of-the-way area, you could also just get chicken wire or welded wire fencing and make a little cage around it, not touching the trunk of the tree.

Now I know that everybody will try to sell you products to repair the damage.

The only thing that can repair the damage is the tree itself.

Anything you apply to the damage is going to make things worse.

Now, so this happened last winter?

- Yes, and it bloomed and did really well all summer, and has beautiful leaves that are turning now.

It looks good.

- Then nothing's wrong.

You always... - Really?

OK. - I know the line is any time the bark is girdled, the tree is dead.

But that's not true of all trees.

For instance, the tree that we get cork from.

Close up our wine bottles.

That cork is the bark, and it's harvested regularly, and the tree doesn't mind.

Same with cinnamon.

That is the outer bark of a tropical tree.

So there are plants in there that can survive this.

But you appear to have done the best thing possible in this situation, which is nothing.

And it's the hardest thing for gardeners to do, because we always want to help the plants.

But a lot of times the best thing to do is let nature take its course.

And if that tree, you know, put out its leaves and bloomed, you don't have any problem there.

But I would make sure you protect it like now, with tree guards or caging, so that the... - Yeah, we had loose caging up to keep the deer from rubbing on it.

So I think we just need to get down to the ground.

I'll get a tree guard.

- Yes, because with for instance, with chicken wire, I now think about it, mice and voles can go right through the holes.

So I think you want to invest in a couple of real tree guards.

And they're not expensive.

So it should be easy.

Just make sure you take them off in the spring.

Because especially if they're covering a wound, you don't want them to get sucked in there, so to speak.

- Okay.

Great.

Well, I'm glad there's hope for the dogwood.

Thank you very much.

- Oh, thank you.

It's my pleasure.

And good luck to you.

- Thank you.

Same to you.

Bye-bye.

- Bye-bye.

All right, it's time for a very important Question of the Week... Ed from Delaware left us this phone message.

"My Emerald Arbor Vitae are starting to die.

"They're turning brown.

What could be the cause of this?

"I have 15 of them, and five are turning brown."

Yeah, and I'll bet they're all in the middle, right, Ed?

Well, we were originally going to have Ed ask his question on the show in a phone call, and I figured I would offer my usual answers.

Wood mulch touching the trunks of the trees, chemical lawn treatments near the trees, poor drainage, trees planted too deep in the ground, a nearby neighbor spraying herbicides on windy days, or sunspots.

But we've gotten this question a lot lately, and I wondered if something else was afoot.

Or a tree.

So I decided to investigate and turn it into a Question of the Week if I found something other than the usual suspects.

And did I ever!

It wasn't easy, but I finally located a bulletin from the University of Massachusetts at Amherst, that told me all about Arbor Vitae needle blight.

Anyone who has any type of Arbor Vitae on their property should read this bulletin.

We'll include the link when we post this article at the Gardens Alive website.

Anyway, two pathogens are responsible.

Both are poorly understood, virtually unpronounceable, and at least one was unknown before 1989.

Note, all Arbor Vitae are members of the Thuga family, which is why you'll see variations of this word throughout.

I quote from the bulletin.

Oh, God, am I going to have to...?

I'm not going to try to pronounce this thing.

Let's just call it Philo, okay, because that's how it starts out.

It is believed that philo is the primary species encountered.

This fungus was first described in 1989 and is thought to occur only on thuga species, but based on submissions to the University of Massachusetts plant pathology lab, this pathogen can also be found on label in Cyprus.

False Cyprus, Japanese cedar, and juniper/red cedar.

Infected arbor vitae typically have blighted needle tips and/or discolored pale green to yellow needles that may appear desiccated, means they're dried out.

Infections often initiate at the needle tip and progress inwards.

During wet weather, black pads of fungal tissue rupture through the epidermis on symptomatic needles to release large volumes of spores, which are then blown or splashed onto nearby shoots to initiate new infections.

Now, because arbor vitae have dense canopies, especially those that have been pruned for deep density, ideal conditions exist for the development of this pathogen.

Most infections are likely to become established during wet weather in the spring, when new needles are emerging and not yet fully developed.

However, the pathogen may also be actively sporulating during the autumn season, especially when moisture is abundant.

Overly aggressive pruning and winter injury are likely the most important stresses that lead to infection.

The fungus invades the plant at the tips of new shoots, or it can utilize pruning wounds as a source of entry.

Once established, it causes browning and dieback that can eventually kill small branches.

Overall, the second pathogen, which we'll call pesta, is more aggressive in comparison to the other one because of its ability to attack stems and small branches.

Thilo is primarily restricted to the needles.

Pesta is opportunistic and attacks weakened plants predisposed to infection by drought, insect feeding, mechanical damage and planting stress.

This fungus is a known endophyte, meaning that it can live dormant within the plant without causing disease and adaption that allows it to readily overwinter in asymptomatic plant tissue.

Pesta produces small pads of fungal tissue underneath the epidermis of the plant, and when moisture is abundant, the pads rupture, producing a long black mass of spores.

During wet weather, these spores are blown and splashed onto healthy nearby plant parts, initiating new infection centers.

The best course of action for management of any needle or shoot blight pathogen is to prune and discard as many infected plant parts as possible.

Dead shoots and needles harbor the fungal pathogens and allow them to overwinter in the tree canopy.

When they sporulate, or is it spore-you-late?

I don't know.

I just love that word, from the dead tissue the following spring, the spores are in very close proximity to newly-developing and susceptible plant tissue.

On well-established, mature trees, this level of pruning can be a daunting task, but a necessary one if the disease is to be successfully controlled.

However, it is important to keep in mind that spores travel long distances, and both pathogens are widespread in the environment.

Avoid pruning during wet weather, as this is the time when the fungus is most actively producing and disseminating spores.

Avoid watering with overhead sprinklers that wet the foliage, which allows moisture to linger on the needles, facilitating spore production and germination.

Drip irrigation, or hand-watering of newly-planted trees is preferable.

End quote.

Now the author, Nicholas Bracey, goes on to mention the importance of cleaning the forest floor, as any infected needles or branches not cleaned up are capable of spreading the fungus.

He also recommends the ancient organic herbicide copper as a way to prevent or control the disease.

Plants should be sprayed with copper in the spring and fall, ideally as a preventative before symptoms emerge.

Sunlight is important, as well.

Although somewhat shade-tolerant, these plants do best in full sun.

The more shade, the better the chance that these two fungi will thrive.

I'm a fun guy!

On a more positive note, kind of, the wood of arbor vitae is highly rot-resistant.

I did not know that.

And would serve well as a frame for raised beds or a compost bin.

So, if you wind up cutting down any trees... Well, that sure was some depressing information about arbor vitae blight, now wasn't it?

Luckily for yous, the Question of the Week appears in print at the Gardens Alive website.

To read it over at your leisure or your leisure, or whatever, just click the link for the Question of the Week at our website, which is still and will forever be... Gardens Alive supports the You Bet Your Garden Question of the Week, and you'll always find the latest Question of the Week, and old ones, at the Gardens Alive website.

You Bet Your Garden is a half hour public television show, an hour-long public radio show and podcast all produced and delivered to you weekly, I also think it's strongly, from the Univest Studios at Lehigh Valley Public Media in Bethlehem, P.A.

Our radio show is distributed by PRX, the Public Radio Exchange.

You Bet Your Garden was created by Mike McGrath.

Mike McGrath was created when he awoke one night to find Captain Nemo's Nautilus in his front yard.

Yikes!

My producer is threatening to attack my arbor if I don't get my vitae out of this studio.

We must be out of time.

But you can call us any time at... We actually got rid of the old calls, and you can really leave a message now, or send us your email, your tired, your poor, your wretched refuse teeming towards our garden shore at... Yeah, and we fixed the problem with the emails, too.

Hey, always include your location.

I'm your host, Mike McGrath, and I'm watching helplessly as evil squirrels replace my spring bulbs and garlic with black walnuts.

And I'll be cursing those long-tailed servants of Satan until I can see you again next week.

- Hi, this is Lydia.

I left a message on your squirrel-hater kind of stuff.

I wanted to add to it.

They're really good about dispersing nuts in the forest.

You said we aren't supposed to feed them, so they can learn how to feed in the wild.

Well, I live in a place where they're tree-haters, and a lot of them have cut down their big, beautiful nut trees.

So there's hardly any native plant elsewhere.

So just keep that in mind.