Scottish Rock Garden Club Forum
Cultivation => Cultivation Problems => Topic started by: Giles on July 17, 2009, 09:16:09 PM
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I bought a Magnolia officinalis earlier in the year, but it has now started producing leaves with underdeveloped/malformed leaves (all midrib and no lamina).The only thing I can think of that I've seen like this is as a result of herbicide damage (aminopyralid being somewhat topical), but it has had no direct exposure or applications of manure etc that could account for this. Any ideas?
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It looks very poorly, Giles. Might it have suffered some damage from a weedkiller before you got it, which is only manifesting itself now? Have you repotted it or planted it out? I'm wondering if the compost might have been contaminated ......lots of similar damage this year from manured compost that has herbicide residues, as I expect you know ........ not sure what action might remedy the problem..........complete washing off of compost from roots and replanting, giving feed and lots of water.... in effect - trying to flush the system........ :-\ ???
No chance of "drift" of herbicide from passing municipal workers, for instance? That happens here in town quite a lot :'(
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My borough council hires outside contractors to spray weeds. They do this on quads with a spray bar at the back and a hand held lance for spot spraying. The do this even in windy weather. When I see them I tell them to to spray near my garden
Is it possible plants are getting resistant to Roundup? I sprayed weeds a few weeks ago on my drive, around the house and in a neighbours garden. They are still alive!
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Giles,
You have never had a water can that you have used for weed killer standing empty near the plant have you the reason I am saying this is when I was part time in a large Garden Centre a customer came in with a tomato leaf just like that I told her it was weed killer she said she had never used it near the Greenhouse it turns out she had washed the water can out but stored it in the greenhouse and the fumes did the damage.
Derek
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You have never had a water can that you have used for weed killer standing empty near the plant have you?
Buy a special watering can for use with weedkillers. Its color should distinguish it from all your other watering cans. For example, you may have dark green cans for regular use, but a shocking pink one for weedkillers. A refinement is to mark it with the word WEEDS in large letters so anyone unfamiliar with your color scheme has a clue.
Keep your special can where you keep your weedkillers, not near growing plants.
Very elementary methods like this can save a lot of grief in the garden.
Do these forums need a "Hints from Heloise" thread?
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Giles - I have the same distorted thin leaves on a few Magnolia seedlings, various M.'Black Tulip' crosses. I also see one campbellii cross looking exactly like yours. It was apparent in the late winter when they leafed out in the greenhouse which was quite cool at the time - +5-+7c. They grew out of it and then repeated the same growth during our recent 7+ week course of gloom. I assume part genetics, part weather but I may be off course, a shot of magnesium sulphate or dolomite might unlock some nutrients as well. Some grow out of it in time, others go down and some need to be trashed. I'd say don't panic just yet.
I will add a photo to this tonight if I can take the heat in the greenhouse.
johnw
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Hi Giles,
Could it be attacked by virus?
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I think it was due to hormone weedkiller damage.
Since being planted out, although the growing tip has aborted, many side shoots are now breaking out.
I think the exposure was before I bought the plant,( a M. x wieseneri from the same nursery was similarly effected).
I always keep separate cans and sprayer for weedkillers, and keep them on the opposite side of the garage from my usual kit.
The RHS have a useful bit on their website: http://www.rhs.org.uk/news/pressreleases/pdffiles/WeedkillerUpdate250708.pdf
I broke up the root ball, to allow a good interface with soil microbes, and it's doing fine now.