My yellow shrub daisies were blooming great but now they have not bloomed in a good 2 1/2 months. I believe they had spider mites and I sprayed them but need to spray them again this weekend. The foliage looks good, but I noticed the bottom of the plants had a grey look. Could the spider mites keep them from blooming at all?
Treating the plant with neem oil should help with eradicating the spider mites. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
While mites can occasionally affect blooming, this isn't always the case. You may need a bit more phosphorus, which helps promote blooming. this article should help: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm