Garden Panic - Level 25
I composed this walkthrough after gaining quite a number of stars, but estimated how many I'd have if I were starting level 25 for the first time. These are the stars used during the making of this walkthrough, but all of them are not necessary, and you should be able to pass the level with fewer.
This level is about uncertainty -- where should I put my plants??? Which way will the bugs go? The answer is to catch them at the ONLY certain points -- the entry or exit: they all start at the burrow and end at the strawberry bed. This walkthrough builds up significant damage zones right at the burrow entrypoints. Of course, some of the critters are liable to escape, so create an insurance plan by planting defenses at the strawberry patch end.
In later waves, the pests become quite difficult to defeat, and plant placements in the middle help kill bugs that cross over, and should have range to damage the ones that go the top or bottom path.
Begin with the starting plants as in the picture.
Then plant a corn at 5, cactus at 6, peashooter at 7, cactus at 8, another peashooter at 9. Plant a tomato at 10, poisonflower at 11, and peashooters at 12 & 13.
You are looking to create a mirror-image setup, since the composition of bugs from each burrow is unpredictable. Poisonflowers damage the bugs right as they leave the burrow, corns (at level 4) stun enemies, giving the tomatoes a chance to hit multiple targets. Peashooters damage both air & ground bugs, but are critical to keeping your ground enemies in check.
After this, upgrade the first of the peashooters once (the rest will not be experienced enough), upgrade the cacti and tomatoes, and the poisonflowers as well. Then add cacti at 14 & 15, to increase your air defenses, and tomatoes at 16, 17 to provide an extra level of defense against bugs that escape your initial bombardment. Add a tomato at 18 at make up for the lack of a peashooter mirrored on the other side.
Upgrade the central peashooters, then upgrade the corns to level 4 to start stunning them around the main damage area.
After that, upgrade plants evenly around until the end of the level, none need be upgraded past level 4, (the 150 level). Prior to the final wave, sell your cacti, and upgrade the tomatoes & peashooters near the burrow -- you'll need them!
There is some danger in this level of an inability to upgrade plants close to the strawberry beds. If you find that most of your bugs are ending up there, consider placing peashooters/tomatoes there in the early stages of the level so that they gain more experience and be upgraded.