I have started a new game and I have found a bit of a trick. When you start out and are on the 1st or 2nd level of dirt and water. The strong plants are very weak. If you get one seed out of them great and then hit the space bar to pause the game, then go sell your plant you can leave it in there as long as you want it wont age since the game is paused. With the bugs, when my plants are growing I always have my net in hand usually 2nd row middle plant. When a bug comes by hit ALT and then swipe at the bug.