Hibiscus was flowering when we bought it

Question

We had some cool and windy weather and after that it looks like it has some disease attack it. Some leaves have turned yellow with black spots, but most leaves are a healthy dark green but no flowers.

Answer 1

I suspect your hibiscus has a fungal infection which can be treated with a fungicide. For verification, here is what a fungal infection on a hibiscus looks like:

http://www.hiddenvalleynaturearts.com/images/blackspots1.jpg
http://www.hiddenvalleyhibiscus.com/images/blackspotssm.jpg

Have you fertilized your hibiscus? That may encourage it to bloom as a growing hibiscus needs lots of nutrients in order to bloom well. . For more information on fertilizing hibiscus, please visit the following link:
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-fertilizing.htm

Additionally, hibiscus will be more inclined to bloom if their care plan is being followed. I recommend a double-check on the care of your hibiscus using the following article:
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/how-to-care-for-hibiscus-plants.htm