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Re: [SG] Mystery Disease

The astilbe problem sounds like some kind of fungal die-back.  If they are
still alive at all, you might try spraying with a fungicide.  That sudden
collapsing is usually a disease, not an insect attack.

I'd just whack the columbine back to the ground - they will put out new
leaves.  I do this to mine as a matter of course about this time of year or
a bit later - depending on whether I'm saving seed or not.  If you see the
larvae, caterpillar or whatever, you can spray with Bt - but it's easier to
just cut them back.  After bloom, I have noticed that columbines go into a
short semi-dormancy phase and then put out new growth.  They will do this
whether you cut them back or not, but since the leaves (on the ones in my
garden at any rate ) are generally fairly ratty by the time they start to
set seed, I just whack them back.

I've had the same problem with Helichrysum petiolatum.  Have never seen the
adult insect, but the problem is caused by a leaf minor and they can
devastate a plant.  The only thing I've done is remove the affected leaves
(very tedious).  If not too far gone, the plant will leaf out again.   Or,
you can give it a severe haircut instead of cutting off or pulling off the
affected leaves.  If you want to go the leaf by leaf routine, you need to
examine the leaves closely as those affected will have a tiny hole in them
or a sort of transparent spot if you hold them to the light before you
notice the curling and the larvae droppings.  It's a royal pain in the
derrière, but I really like this plant and try to keep them going and in
semi-decent condition.  I've had this problem with *every* plant of
Helichrysum I've ever gotten...for years and years...and sometimes think
they come from the nursery already infected.

Marge Talt, zone 7 Maryland
mtalt@clark.net
Editor:  Gardening in Shade
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----------
> From: Tim Wilson <tpwilson@GWIS.COM>
> Date: Thursday, June 04, 1998 8:26 PM
>
> I NEED HELP!!
>
>     I have several white astilbe that are beginning to die and I can't
> explain why. First symptoms where a sudden drooping look and over the
> past several days the plant has begun to shrivel up. I thought it was
> isolated to only one plant until this evening I have noticed several
> others with same problem. Plants were on the verge of blooming (flower
> stalks grown and up but not open). The astilbe "Pumila" and pink astilbe
> have not been affected. The area has received plenty of water (who
> hasn't in the tornado alley of the upper midwest) but also has good
> drainage. No otherr planys seem to be affected.
>
>     Also I have been attacked by a green caterpillar on my Columbines.
> They have stripped several plants to the bone. They leave small black
> specs on the plant. What is it and what can I do? I am not against an
> organic solution but with no desire to start a war I am also not against
> dropping a nuclear bomb or two. Any suggestions?
>
>     One last bug question. I have hanging baskets with liccorish
> (spelling?) as a trailing plant. The ends are being attached and curled
> up in a web by something I cannot locate. It also leaves the small black
> specs or droppings inside this fine web. What is it and again what can I
> use to eliminate them? They have no affect on the viburnum that is in
> the same baskets.
>
>     Thanks in advance and thanks for the patience on the basket question
> as I realize it is not a shade plant question.
>
> Tim Wilson
> Chagrin Falls, OH
> zone 5
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