I do all my adjustments on layers as not to harm the orignal.
First thing I'd recommend is using the crop tool to correct the verticals, feels like you have a short leg.
Then create 2 adjustments layers for saturation and colour balance. The picture needs warming up and colour bringing out of the flowers.
Possilbly an axtra layer for brightness/contrast to whiten the building a tad more. You can always use the ereaser tool over the adjustment layer to mask out the effect on other parts of the image.
Hope that helps