Of course in the general run of things then most gardeners will grow vegetables under hydroponics conditions. However this is not always so. Especially when starting off when growing young plants. As can be seen flowers can be grown under strict conditions when using hydroponics. To start with a strict control can be used to measure the correct amount of light. In other words lighting can used to lengthen the amount of daylight. So, tricking the young plants about the time of year. Importantly, this can be seen when driving passed the large growers.
Glasshouses are lit to give the flowers a full days sun light. Of course this is the reason that we can buy out of season flowers such as roses. Not too long ago then roses could only be bought when in season (summer time). Now because of hydroponics and day light extending lighting systems then roses can be bought at any time of the year.
Of course the other big advantage with hydroponics is that plants including flowers can be grown with full control of nutrients. So growing without soils enables the flower plants to draw in nutrients into there roots. At the same time the young plants are not effected by pests such as weeds disease or insects.
Hydroponics can be used by large and small growers alike. As I have siad in the past then I started out with a self watering system. Consisting of a plastic reservoirs for the water and nutrients to be added. Also there are various systems for connecting up plastic piping to you growing pots. So, the video below gives a good example of what can be done using hydroponic systems to grow flowers.
Although I do grow my own flowers, so they are mainly used as companion plants. For example, I use French marigolds to deter white fly from my tomato plants.