A lot of things play into that. Sunlight, temperatures, moisture, fertilizer and so on. One of the biggest things is the age of the plant. We have a rose bush in our yard that is many years old. I am guessing 30 years or better. Every spring it produces tons of roses. For the type of rose, they are pretty big.
However, if we would prune them and allow only one rose per stem, the rose blossom would be much bigger. It is the same with fruit trees. The less fruit they have to feed, the bigger the fruit. Same with a rose bush. More flowers to feed means less nutrients for all the roses.
You can see how this could be a daunting and time consuming task. That is why some of the roses grown and sold as cut flowers are so much more expensive. Time and more time goes into farming them. Feeding, pruning and caring for the bush so that only the most graceful and elegant roses are produced.
I can only imagine how many hours are spent on farms raising roses on the farms. It must be truly a love of what the growers do to put so much care into the roses. So next time you see a huge rose at a floral shop, remember all the work and planning that went into growing that elegant blossom for your pleasure.
