When you go about planting flowers in your flower beds and gardens, you might miss the occasional flower that you really wanted to include and you find out that it is past its prime planting season. Can you still plant flowers after their prime window? The short answer is yes, you can. However, there is a long answer to that question as well. You need not worry so much about planting flowers past their prime window but whether their location and the current climate are suitable for the flowers past their prime window. If their prime window is during early spring but they are a flower that usually grows in the south, those above the Mason Dixon line should have no trouble at all.
Sometimes it is all about finding out why the flowers you want to plant have their prime window. Is it temperature related or is it moisture related? Either way, you can usually figure out if your surroundings can offer the flowers you wanted to plant earlier the desired forecast. Can you make up for a natural depletion of water that happens in the summer months? Are you able to provide the flowers enough shade to offset the blazing summer sun? These are simple questions that can help you answer whether or not you can plant the flowers you wish to plant even if you have missed the prime planting window. Otherwise, you can always try to plant them indoors and move them outside the following spring.