rose flowers have faulty bloom | New Gardeners | GEEKGARDENER

hi there, I am a newbie gardener in JP nagar bangalore. I have bought some rose flowers from nurseries near Big banyan tree and kept on my terrace. I am now observing faulty bloom in my roses. When i bought them they had very beautiful flowers but now all new buds that bloom are getting faulty bloom.

Planting Environment :
1. Potting medium :: Rose plants is in pot. soil is of type clay.

2. sunlight :: pots are on terrace. sunlight available for whole day. I moved it now under a tree branch shade where it gets partial sunlight during peak hours ( 12 pm to 3 pm). Plant leaves that were also burning have recovered because of that but blooms are not recovering at all (considering new blooms also).

3. water :: once daily in morning. I do not wet the leaves.

4. fertilizer :: NPK once in 15 days. mixed in water an applied only to soil.

5. pesticide :: Keracid. once in a month. 10 drops in a litre. sprayed on the plant and blooms in morning.

Please advise. Pics : https://www.flickr.com/photos/.....93521@N08/