Answer: Mallows are closely related to hollyhocks and subject to rust infection as well. It is difficult to control. The best preventives are to do a thorough clean up of all plant debris in the fall and dispose of it in the trash. Also remove any weed malvas nearby. Allow ample space between the plants to increase air circulation. Avoid wetting the foliage if you water. You may also want to plant something in front of them to block the view of the bad foliage. I hope this helps!
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