I agree with Amadeus Forzin, it looks like an outdoor bug damage. Handling insect pest is not an easy task at all. The warm, moist conditions in plants favor the growth of many pests and diseases as well as your chosen plants. The best way to keep your plants pest-free is to pay attention to...
seedsoflife, have you checked out the plant. Did you find anything near to it. It can be due to a low or excess of watering or there can be some pest that would have harmed your plant. You can try several do it yourself methods or techniques to save your plant. If you have tried some do it...