Fungus

Let’s Talk Mulch, Shall We?

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In my neighborhood right now, there’s a whole lotta mulching going on. Of course, a few folks have houses for sale, and nothing says, “well-kept home” than nicely mulched beds. I understand that.

But for the rest of the folks, this is exactly the wrong thing to be doing at exactly the wrong time. They might as well go out and trim the hedges when they’re done (and knowing my neighbors, that’s probably coming too–as soon as they’re done having the lawn care companies spread fertilizer on the street. Sigh).

You know me. You know I hate mulch worse than I hate mums. I do understand that for most gardeners, in most parts of the country, particularly the drier parts, it is a necessary evil. But I think nothing is prone to more mismanagement and misunderstanding than mulch (except perhaps fertilizer, but we’ll leave that rant for another time).

So indulge me here while I tell you that unless you live in the far, far northern climes where the ground is just about to freeze–let’s say Alaska or perhaps the intermountain west of the United States–this is the exact wrong time to be mulching the garden. Here’s why.

Mulching at the wrong time in the fall–and by the “wrong” time, I mean before the ground freezes–encourages all the destructive little critters in your area to seek out the newly mulched bed for any number or reasons.

Burrowing animals will seek it out to cache their mast harvest for the winter, thus disrupting your mulch.

Smaller creatures will also seek it out as a place to hibernate (or more properly go into torpor). While that may not sound troublesome, if these creatures are voles (and almost all of the United States and Canada has some kind of vole–the exceptions are Hawaii, Newfoundland, most of Arizona and western Texas) you will find yourself with less plant material than before the winter–in some cases significantly less, depending on the severity of the winter.

If you think you’re not familiar with this phenomena but you mulch in the fall and then find woody plants dead in the spring, you may be more familiar with it than you know.

Of course, in years with extremely heavy snow cover, even those of us that don’t mulch can find ourselves losing plants to voles. They tunnel under the snow and feast on the shrubbery, protected from their predators the hawks and owls. But not even I can control the weather!

But At least I do what I can by not mulching in the fall!

Wordless Wednesday–the Good Guys

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beneficial fungus

A garden writer of my acquaintance has won awards for his books Teeming with Microbes and Teeming with Nutrients. The Microbes book is about the soil food web and the beneficial fungi (among other things) that live within it.

I’m well aware of that relationship when I garden “in the wild” in the garden and that’s why I try never to spray anything–organic or not–in the garden. I try not to destroy the soil ecosystem I’ve carefully built up in my garden.

For those of you that rototill, take note. This is a house plant. It had gotten too big for its pot in just one season (which surprised me). When I dug it out of the pot, this is what I found: all this beneficial fungus on the roots. Clearly this was helping the plant thrive.

I have no explanation for why this plant developed this this year. It surely wasn’t because of rainfall–we’ve been fairly dry. All I’ll say is that I’m grateful.

By the way, I re-potted 6 other plants this weekend. Only this plant had this good fungus. Very interesting.

Looking Back At The Difficult Summer

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As this past summer goes, here in New England, we’ve been blessed.  We didn’t have very many 100+ days, we had drought, but it wasn’t the searing drought that so much of the rest of the United States had, and when the rains came, for the most part, they did not bring with them the damaging winds that so many other parts of the country got.  Connecticut was, I believe, even spared its usual tornado or two although we did have plenty of watches and warnings and occasional straight line wind damage.

So I found it interesting that I was getting so many calls for my “Putting the Garden to Bed for Winter” lecture.  And judging by publicity for other speakers, I see that they are getting the same requests.  I have to wonder what’s behind this and I’ll certainly ask my groups when I speak to them (after the lecture of course).

I have a couple of theories. First, I wonder if it doesn’t have to do with the fact that none of us could “Put the Garden to Bed” properly last year because of the freak October snowstorm.  For most of us, the gardens lay under a tangle of vines, broken branches with wet, brown leaves and who knows what else, until springtime came.  As a result, many people lost plants–or thought they did–because of that.

For those that were able to get the gardens cleaned up–or out–last fall, after the storm (and I was one of those) what I found this spring  was even more disheartening!  I’ve never had as much dieback on my hydrangeas as I’d had over the last winter (I’ve spoken about this before–and even shown photos–for those of you that are longtime readers).  I attribute that to the long-term drought which is still continuing here.  We have consistently been 5″ or more shy of the moisture we need since the beginning of 2012.  Hydrangeas, as moisture loving plants–are going to take that worse than most.

The other phenomena that we’ve had is these heavy flooding rains that come all at once.  That’s really not terribly beneficial for the garden. It’s great for replenishing the reservoirs–I’m not going to complain about any rain at all when we get it–but as far as the gardens are concerned, so much of it just runs right off it can’t really benefit them much.

I’ve been seeing evidence of this all over the place–down by our lake, in the runoff patterns leading to it, in my own gardens where the water will pond (hooray for clay soil–at least it traps and holds the rain better than most) and in clients’ gardens where I go to consult and also see runoff patterns in their beds and mulch.

It is said that this is the “new normal:” patterns of drought followed by huge storms.  Again, remember, weather does not equal climate so I’m not going to pass on reasons, other than to say that I firmly believe that we are killing the earth with our behaviors.

But if this is in fact the pattern of what is to come in the future, we’re all going to have to change how we garden–and how we grow food, for that matter, both in our own yards and on a large scale.  But that’s a post for another day.

What’s Wrong with My Rose Leaves Now?!

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Earlier this month I did a post on the rose sawfly larva chomping on the backs of my rose leaves (and this year they were so bad they were chomping on the tops of the leaves, and the stems and even the buds–but I digress!).

I had photos of the leaves looking a little like stained glass windows–without the pretty colors.  If you think that sounds more like the problem you’re having with your leaves, you can jump over to that post here: http://wp.me/pOm4T-1gV

Now there’s this: this is a whole separate problem.  Usually most of my roses don’t have this problem, and so far this year, only my yellow rose,’ Charlotte’ is showing signs of this fungus called black spot.

What am I going to do?  Nothing. Remember my Black-eyed Susan post where I said that fungicides only control a problem they don’t cure it?  So what’s the point? These leaves will drop off.  I will clean them up.  That’s the extent of my intervention.

I also won’t water overhead, keeping water off the leaves–but I can’t give that advice to nature, who is causing this problem to begin with. Once we get into our hot dry days of July, this problem will self-correct.

By the way, most folks do seem to love yellow roses and I’m included in that “most folks” category.  However, yellow roses are genetically the weakest rose.  The bloom the least and are the most prone to every pest and disease out there.  Therefore, if you truly want to have an easy care rose garden, select your yellow roses very carefully.  This rose is a David Austin™ rose.  And while they are very hardy for me, they are not generally known for their disease or insect resistance.

The other thing that I obviously haven’t done is given my roses enough space.  Roses are supposed to have 2′ around them for good are circulation.  My poor roses are lucky if they have 2″ around them in spots.  For the roses with “good genes,” this doesn’t matter.  For those with less robust genes like poor ‘Charlotte” here, she’s going to catch every fungal spore that blows by.

And then, because she’s already weakened, the few Japanese beetles that I do have seem to find her the tastiest too.  Isn’t it interesting that the insects know the plant that’s already in a weakened condition?

There are “easy care” yellow roses but unless ‘Charlotte’ gets plowed under in a snowstorm or something, I won’t pull her out.  She has sentimental value for me, even though she might be the wrong plant in the wrong place at this point.  The original 4 David Austins in this garden were the last things I planted with my dad before he passed away in 1999.

So unless something happens to one of them, they will stay there, even though they are not native, and even though insects seem to like them more than they should and they require more work than most other parts of my yard at this point.  Because gardening connections to people you love who are no longer with you can’t be explained–and sometimes they are worth all the work.  After all, they are beautiful too!

There IS Fungus On The Black-Eyed Susans

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Back in June I did a post about the black spots on the leaves on black-eyed susans (rudbeckia  species) being caused by leaf eating beetles and not a fungus.  It is consistently one of my highest read posts.

If this photo doesn’t prove that hypothesis, nothing will.  We’ve had a very wet late summer here in Connecticut–things are mouldering away on us faster than we can cut them back.  As I was cutting back some of the stalks on the black-eyed susans last weekend, I came across these strange fungal growths down deep in the leaves.  If the photo’s a little unclear, what they appear to be are almost solid puffballs of a powdery grey substance–as if a mushroom of powdery mildew has surrounded the stem.  Delightful!

Notice, however, that they leaves around them are pretty much unaffected by any fungus or black spots themselves!  They do have a bit of the white fungus on them as you would expect–but none of the “black fungus” caused by the beetle–because it’s not a fungus, of course.

Fungus Among Us–Cedar Apple Rust

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Last May I did a post on Cedar Apple Rust.  At the time, I mentioned that it was a symbiotic host and that it affected plants in both the cedar/juniper families and in the malus family–apples, crab apples and the like.

In that post I showed this spectacular orange gelatinous mass hanging off a juniper–a lovely thing–and mentioned that in the following year apples and crab apples were affected.  Well–here we are, one year later and here’s what it looks like on a crab apple.  Not nearly so spectacular but surely disfiguring.

This is where the fungus gets a little more interesting–when you turn the leaf over and see the fruiting spores of the fungus.  This is roughly equivalent to that gelatinous mass on the junipers and cedars.

As this Bulletin from Cornell’s Cooperative Extension further explains, the two fungi have  a rather complicated inter-relationship.  And apparently there needn’t be a year between the appearance of the fungi on the cedar and its corresponding appearance on the crap apple–they can appear in the same year according to Cornell.

The reason I’ve never treated my crab apple is that fungicide–lime sulphur spray to be exact–is supposed to be applied to the first time while the tree is still dormant in February.  Think back to what you all remember about February.  Rarely is there a time when I want to venture out, particularly to spray a fungicide!  It’s all I can do to get out and walk the dog!

Then you’re supposed to spray twice more, at bud break and after flowering.  Well, that’s entirely too much spraying of chemicals–even if they are quasi-organic–in my yard, particularly since this tree has had this particular fungus for 15 years now and doesn’t seem any worse for it.  And if the time comes  that it does become a problem, I think the tree will need to go.  No high maintenance trees in this yard for me.

But until then, the birds do enjoy the fruits–so I’m hopeful that the tree will continue to shrug off the fungus just as the dogwood does with the anthracnose.  The birds enjoy the dogwood fruits too.  So there will be no spraying in this yard.

Fungus Among Us–Botrytis

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Back in my retail gardening days, if we had a very wet spring, I would get the question about why the customer’s peony buds were turning black and falling off.  In fact, if you look closely in the photo, down at the base of one of the leaves is a tiny black bud.

This is the classic case of peony botrytis, a fungus that affects peonies in damp, wet weather.  Fortunately, my peonies bloomed beautifully this spring and it is only this late season latent bud that is affected.

But as I was looking for an informative link for this post, I was surprised to find that my geraniums had botrytis this spring.  Now I knew they were rotting from all the rain in May and June (hard to remember that, isn’t it?)  And I knew I was pulling dead, fuzzy, icky leaves off the stems.  But I wasn’t thinking too much about what particular type of fungus they had–I was just trying to stop it (and thankfully I did–quick action, good soil drainage and clay pots helped).

So here’s the article from the University of Illinois that helped me have my “aha” moment.  That’s the great thing about gardening–you can always learn something.

So you just heard me describe what I did for my geranium.  And what I’ll do for this poor peony is cut off all the foliage and discard it–not in the compost pile but elsewhere so any spores do not accidentally get spread elsewhere.  But  this peony is not in a good situation–it’s hemmed in too closely by black-eyed susans.  So even with my good cultural practices, in hot and humid weather, the fungus will likely be back next year.

So long as it’s at the end of the season, I won’t care.

Fungus Among Us–Anthracnose

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Anthracnose is a fungus that most associate primarily with our native dogwoods, cornus florida.   In fact, that’s what the above photo is of–anthracnose on my white native dogwood.  It doesn’t kill them–this tree has had anthracnose just about every year that I’ve lived here and I’ve been in this house 19 years now.  But it is disfiguring and it can weaken the tree and leave it susceptible to other problems that dogwoods are susceptible to like borers, so it’s not a good thing.

 A close up of this leaf shows how truly disfiguring the fungus can be. And because it overwinters not only in leaf litter but in small branches and shoots, it comes back year after year (as I’ve mentioned, this tree has had the fungus every year since I’ve lived in the house).

As this Fact Sheet from the University of California show, anthracnose is not just a disease of dogwoods, however.  It can affect many other hardwood trees and ornamentals as well as fruits and vegetables as well. They suggest that the fungus can be managed on a small scale (presumably with the veggies) with a fungicide but I wouldn’t want to eat vegetables treated with a fungicide so I just let my cucumbers die every year once they get that wilt spread by the cucumber beetle.    Some years I’ve planted late enough that I’ve missed the beetle–and the wilt–entirely.

The Fact Sheet from UC Davis has a list of resistant cultivars that can be planted in lieu of susceptible varieties of plants and I was pleased to see not just the Kousa dogwood, which doesn’t have a very high wildlife value but the Cornelian Cherry (cornus mas) a very early blooming type of dogwood with pretty yellow flowers and a smaller reddish fruit that has a much higher wildlife value than the kousa.

If you are searching for an alternative to our native dogwoods and don’t like the look of those ‘Rutgers cross’ trees, take a look at those.  You do have to like yellow flowers though.

Fungus Among Us–Powdery Mildew

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It’s easy to see how this fungal disease gets its name, isn’t it?  You come out one morning to find your plant dusted with talcum powder.

A close up of the leaves and the effect is even more startling.  On this lilac it seems to affect the whole leaf.  On plants like garden phlox (phlox paniculata) which are also especially prone to this fungus, it will cause the leaf to yellow and drop as well giving the flowers a “lollipop” effect.

With a fungus like this, it’s very tempting to want to treat and treat immediately.  Not only is the fungus disfiguring, but in the case of the phlox, it’s unsightly as well.

You can treat–but as I remarked yesterday, prevention is much better than treatments since fungicides only control and do not cure once the fungus is present (remember for next year–it’s too late for this year.)

But powdery mildew doesn’t invade the tissue of the leaf so it’s not really doing the plant any harm (despite the fact that it may be doing harm to your eyes to look at it!)  So not treating at all isn’t going to affect the plant from one year to the next.

Now in the case of the phlox, where you have leaf drop, I’d advise you to clean up the leaves and remove them from the garden and do not compost them so that you don’t have any spores that might over-winter there to re-infect.  But chances are you have the cultural conditions present that this fungus likes and you will have the fungus again next year.

In the case of phlox there are some things you can do for existing plants to try to control the fungus.  You can remove every other stem to improve circulation within the plant, or cut down the outer stems by 1/2 to achieve the same effect.  It’s worth a try.

With a lilac it’s a bit harder.  Mine’s in a bit too much shade.  And unless I want to take down some trees–which I don’t–or move this established plant–which I also don’t–I have few options.

This bulletin from Colorado State discusses the disease and its controls in a bit more detail than I have.  It also give you some chemical controls–which you know I don’t endorse.

Fungus Among Us–Black Spot

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Since we just finished talking about roses last week, I thought I’d discuss one of their most disfiguring problems this week since all this week I’ll be discussing what happens to plants when we get hot and humid weather.  As you can imagine, my approach to all of this is rather hands off, but some folks do like to treat.

Two things I’ll tell you about fungal diseases–they are easier to treat before they are a problem.  So if you have them this year, plan to treat proactively next year.  Next, fungicides are much better at preventing problems that they are at curing them.  Once you have the fungus all they can do is manage it.

I’ll also tell you that it is a rare fungus that will kill a plant.  Sometimes you will wish that the plant will die because it gets so ugly–but that’s a different thing.

Blackspot can be prevented in roses by giving them good air circulation.  You can see that I break that rule and so I’ll have issues.  This David Austin™ rose is underplanted with both a smaller Fairy rose and with catmint.  The catmint deters the japanese beetles, but it runs amok in the garden and probably causes moisture to linger, hence the blackspot.

What do I do?  Nothing.  When the leaves get too diseased, I pull them off and throw them in the trash.

Should you wish to be a little more proactive than I am, there are lots of good organic remedies that are easy on the environment.  Neem oil is said to be a fairly decent fungicide in addition to being a pesticide.

If you’d prefer to use something less toxic than that, a 50%/50% mixture of milk and water is always a good remedy.  Just be sure to clean out your sprayer after every use.

I’ve heard that liquid seaweed or liquid kelp sprayed on the leaves is also a good preventative but I have not tried it myself.

And finally there are organic fungicides on the market, but they do vary in toxicity to bees and other beneficials so be sure to investigate those before using, even proactively.