Tag Archive | Disease

Is There Something Wrong With My Hosta?

 

20170806_131212Hostas are wonderful shade and even occasionally sun plants–bone hardy in the cold, increasing in size every year so that you can divide them and either spread them around your garden, share them with friends, or have plants to sell at your garden club’s plant sale (but do be aware of those patented varieties!)

But what happens if you notice a hosta that’s not behaving like that?

 

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Well, first thing first, take a closer look. Might you have a pesky underground rodent like a vole nibbling on the roots?

Are deer or rabbits nibbling at it from above? Is a woodchuck eating it from both sides?

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If none of those things seems to be occurring, take an even closer look at the leaves. Do they exhibit anything out of the ordinary? If so, you may have a hosta infected with hosta mosaic virus, otherwise known as hosta virus X (HSX).

How does this  virus manifest itself? It can appear any number of ways. The leaves can appear puckered or stippled or stunted. The color can appear broken–in fact, when the virus first appeared, many breeders thought they had new unique variations among hostas on their hands before the virus was recognized.

This fact sheet from the University of Wisconsin not only has some great information about the virus, but has some great photos of infected leaves.

HSX has been around since 1996 but I know when I was working in retail gardening (from 2001-2008) it was only beginning to be recognized as an issue so that tells you how long it took to catch on, even in the trade.

Thee is no cure for HSX. Infected plants need to be removed–carefully–from your garden and destroyed. Do not compost them! And now, after re-acquainting myself with these photos for this post, I need to go out to take a hard look at a couple of my own hostas!

 

 

 

 

Powdery Mildew

Powerdry Mildew on Crape Myrtle

This is a Black Diamond Crape Myrtle called Pure White. I don’t think they meant the leaves, however. It, along with the one next to it, Best Red, were sent to me this spring as test plants to see about their hardiness. Unfortunately they arrived fairly battered so I’ve been growing them on in the pot to try to get them to a decent size for planting.

Each plant is affected by mildew. Nothing around them–annuals, tender perennials, and behind them are perennials and shrubs planted in the ground–are affected so I’m going to say that it is a particular characteristic of these plants that makes them susceptible. I am not amused. I don’t like finicky plants.

But maybe they’re not getting what they need. This is the “temperate East” as I persist in reminding folks and it has been way cooler than normal this summer. Maybe they need to bake. They are not baking this summer, although it has been a lot drier than normal. It just hasn’t been quite as warm as normal. Perhaps I ought to set them on the driveway where they’ll get more sun. Perhaps they’re not getting enough.

How will I treat them? Disease is a funny thing. Once plants have it, it’s hard to treat. And I’m not a huge fan of spraying stuff-any “stuff” whether it’s organic or not (despite the Spoiler’s latest transgressions) because whatever gets sprayed tends to affect insects that land while what you’ve sprayed is still wet. If I do spray anything, I’ll spray in the evening, and I’ll take these to a place where I hope there are no pollinators nearby.

And I might try my “old farmer’s remedy” first–milk and water–just in case. The Spoiler’s already done enough harm for 1 summer.

Why Is My Black Lace Wilting?

With a title like that, this could almost be a Victorian murder mystery or something.  But no, I am talking about one of my least favorite plants, sambucus nigra ‘Black Lace, ‘ or Black Lace elderberry.

I say least favorite because it is the plant that has reputedly had the most number of words ever written about it (and here I am adding to that).  But it was supposed to be the cold climate gardener’s answer to a prayer–if they couldn’t grow a japanese maple, they could grow ‘Black Lace.

I don’t have trouble with japanese maples but I sure am having trouble with ‘Black Lace!’  It was extraordinarily slow to start and slow to grow and lo and behold, just when I got it to a respectable height and it started flowering, I have this:

What appears to be happening is the stems are shriveling up and dying.  Here’s a close-up of this delightful phenomenon.

Research across the internet indicates that all elderberries are susceptible to verticilium wilt, but typically that would come later in the season, would result in the entire branch dying back, and would begin with a yellowing, not with this blackening.

I did note that the plant had aphids earlier in the season.  One of the reasons that aphids should be managed is that they can and do spread diseases of both the viral and bacterial kind.  I suspect that this is what has happened in this case, although I have not found any independent sources that confirm this.  No internet sources even indicate that aphids are a problem on these shrubs!

I will continue to watch the plant and to prune off the wilting parts if they become too severe.  I would hate to lose it for the wildlife value–the birds value the fruit.  Other than that, if it dies, I surely won’t mind at all.

{See post of June 17 for a follow-up–it turns out there are stem borers in these stems}

{Because this is by far my most popular post, I contacted Proven Winners to see what they recommended as a control for these borers.  They recommended giving the shrub a hard pruning, which they say it will take.  That’s fine if your shrub is mature.  Otherwise, I guess the control is still just to prune off the affected areas!  It is a lovely shrub for wildlife!}