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Cornmeal/Polenta and Rose Black Spot

K67 · 2021-03-11 18:53:17

Reading the other day that a handful of cornmeal round your roses, worked in and watered as new leaves appear and repeated monthly is supposed to keep a rose clear. Has anyone tried this before I add it to my shopping order? Cornflour/cornmeal contains a fungus called Trichoderma which destroys the fungus that causes black…

Posts

edhelka Posts: 2,351

October 2021

I looked into buying Trichoderma directly in past but decided against it, there just isn't enough evidence to support any significant benefits.

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