Myrtle Problem with Leaf Spots

I have a myrtle growing in a pot. It has developed some brown spots on some of the leaves mostly near the top of the plant. I am in Wisconsin, USA and it sits in a south facing window. Any idea of what this could be??

The most likely cause is that the plant got a bit too dry at one point, probably at least a month ago. Possibly you started heating the house at that point , which resulted in much drier air and much faster drying of the soil. Since the plant has leathery leaves, it takes a long time for damage to show. It is one of the plants that dies if it is allowed to dry out completely, even once! The dryish spell damaged roots and now the plant cannot take up enough water to sufficiently supply the top. The top is more exposed to the sun and so the leaves show sun damage. Keep a bit shadier and evenly moist for the next month, by which time the roots should have regrown and you can slowly increase light.
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