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Oxalis/purple shamrock problems

Posted by i_love_flowers 5 (My Page) on
Tue, May 17, 11 at 10:57

I have a purple shamrock that I bring in in the Winter and recently I noticed that it was looking really bad so I took a closer look. It looks like it might have powdery mildew but I'm not sure. Everything I've read so far make it sound like the mildew should be on top of the leaves. My plant has white powdery circles on the underside of the leaves and the top of the leaves have dark brown/black dried up spots...sort of looks like blight spots. Does this still sound like powdery mildew and what should I use to get rid of it? I have already taken off lots of infected leaves but almost the whole plant is infected so that would leave almost no leaves. Should I just cut the whole thing back and let it start over. Help please!


Follow-Up Postings:

RE: Oxalis/purple shamrock problems

Hello, I love Flowers. It could be mold, but are you familiar with Mealy Bug?
Is it possible your Oxalis has Mealy instead of mold?

Either way, if it was my Oxalis, I'd cut off the leaves, then remove ALL bulbs from soil.
Check bulbs for firmness. If their soft, they''re most likely rotted.
Wash(firm) bulbs w/soapy water. Rinse.
Repot in fresh, well-draining soil. Water. The pot MUST have drainage holes.
Place pot in a bright spot. Water well, but don't keep soil wet. Let soil dry a little between winter, water less.

Hopefully you can save your plant. Oxalix are fast-growers, especially spring and summer. Don't worry about cutting long as the bulbs are healthy, new leaves will return.

Good luck, Toni

RE: Oxalis/purple shamrock problems

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Tue, May 17, 11 at 21:10

ILF - Maybe you could search some of these possibilities to narrow it down: It sounds like it could be chlorotic ring spot disease, a common affliction of Oxalis that isn't treatable. Another likely possibility is Oxalis rust, which usually makes its presence known through the mustard-yellow to light-orange concentric rings on the underside of foliage. The rust IS treatable with a variety of fungicides, and neem oil is fairly effective as both a prophylactic measure and a fix. Graymold (botrytis blight), which might be what you were referring to is another possibility, the treatment of which, with fungicides, is generally unsuccessful.


RE: Oxalis/purple shamrock problems

Toni: thanks for the advice. I think I will end up cutting the whole thing back and see what happens. I'm familiar with mealy bugs and I'm pretty sure that's not what the problem is. Could be mold though.

Al: I don't think it's rust as there is no yellow/orange on the leaves....only white. You mentioned chlorotic ring spot and that it's not not treatable do you mean the whole plant is lost or can I cut it completely back and let it start over? I will do some looking into the graymold and see if that's what it looks like. Thanks for the reply

RE: Oxalis/purple shamrock problems

I Love Flowers.. Since you're familiar with Mealy, it's probably mold.

Don't worry about cutting leaves..they grow fast. But, I'd consider removing them from soil, and repotting.

Oxalis don't like 'too wet' feet..Moist, yes, but not wet.
If you decide to unpot, 'depending on the length of time you had this plant, and age,' there will be a number of bulbs growing alongside the others..Try not to lose them. lol.
Hopefully, you're Oxalis will be fine..Toni

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