Flowers constantly need some little care.
This time of the year flowers need a lot of water. However, it is not good to water them with cold water. They could get a cold shock. It is better to water the plants with room-warm, stagnant water. Best is to refill the watering can after every watering. So the water is already stagnant for the next time. In addition, please make sure to water the flowers only at their roots. The leaves should not get wet because strong sunrays could burn them.
Many flowers are self-cleaning by dropping their dead blossoms. Nevertheless there are also some flowers which do not clean themselves. That is why you should pinch off withered blossoms with your thumb and finger. This allows the flower to build new blossoms.
If your flowers develop magnificently, sooner or later the flower pot might get too tight for them. In this case, you should either prune the flowers or replant them into another bigger pot.