I like the idea and execution, but it needs something more. As it is, there is a clear an obvious strategy of planting with 1 square spaces, since bombs don't take out anything and you really don't have time to plant any more. If I were to remake this game, I'd probably remove the time element and try to make it into a minesweeper type strategy game. I'd probably add some special flower that grants extra points, but only grows if there are at least 4 other flowers near it. This would add more things to consider and make the game-play more complex.
I like the way the controls were presented to the player and although it took me a few rounds to figure out what exactly was the point of the game, I think it doesn't need a tutorial. I like the pixel art; it's very clean and you can tell apart the different objects from each other easily.
I disliked the fact that the bomb flowers kill you, but I guess it makes sense. I just felt that it doesn't fit. I would also make the movement square-based, since there is no reason for you to stand in between the squares - it just makes it frustrating when you try to plant/harvest but can't.
Overall, this is a decent entry to the jam and I enjoyed playing it for a few minutes. Good luck in future jams! :)
Screenshot of the strategy: 