I did the fall image and I just had to do summer! Completely photoshop.
nice style i like it,but…
the colors are very cold,when i hear the world “summer” i imagine very warm colors,mainly red tones and orange,with some soft yellow light tones.(maybe its just me)
the pic itself is simple but nice,looks like a book ilustration.
keep making more seassons 
Too similar to the “autumn” one. While I recognize this might as well be a series, you should still try to vary them somewhat, or else it’ll seem like you found creativity, and then fell into repetition due to atrophy.