Hi János. I'm not really an expert at taking pictures of flowers, but I think that if you want to show a red flower, red background may not be the best choice. The green leaves do stand out well against that wall, but judging by the title, I'd say the picture is not about the leaves.
As far as the composition goes, placing the subject right in the centre of the photo sometimes works, but I'm not sure it's the case here. I'd also remove the wooden stick.