So I've been playing survival endless for awhile and it just doesn't seem possible to get past wave 10. The gargantuars and giga-gargantuars are just too much for my defenses to handle. I know most players use cob-cannons for damage, but the problem is if I put my cob-cannons too far back imps and diggers get to them and if I put them towards the front they get crushed or eaten. Is there a way to get them right in that "spot" where they are protected from imps, diggers, and just the zombies in general? P.S. I play on android so I only have 9 seed slots instead of 10.
For this particular issue the Split Pea (which shoots two peas backwards) could help. Position it in front of the Cob Cannon so it can cover rear attacks.
The PvZ fandom wiki contains a lot of useful strategies for Survival: Endless btw, give it a read: https://plantsvszombies.fandom.com/wiki/Survival:_Endless/Strategies
Also check the 'tips' section: https://plantsvszombies.fandom.com/wiki/Survival:_Endless?so=search#Tips
I recommend looking at some of the online guides for survival, for example this one. There is more than one way to get past this issue. General tips for your question include:
- Do not place the Cob Cannons at the back four lanes on land, where an Imp can be thrown at them or can be attacked Digger. Either place them on on the pool water or in the 5th or 6th columns on land (doing them on the 7th or closer up also works, though they may then be vulnerable to zombies at the front).
- Pumpkin zombies at the back so that they are protected from Diggers. Multiple Gloom-shrooms can be effective at killing Diggers quickly when Pumpkined. Alternatively, two columns of Spikerocks at the back will kill Diggers before they reach the 3rd column
- Frost Melons on each row can slow zombies at the front. This gives the Cob Cannons more time to recharge before Gargantuans can reach your plants in front.
- You won't plant all the plants you want in one round, even with 10 slots. Priotise which plants you want at each round, with a larger focus on upgrade plants including Cob Cannons later in the game.
- Spikerocks being the closest plants to the far right on the land is helpful against Gargantuans since they take 3 hits to be destroyed, a luxury that other plants do not have.
- As a late-game goal, Pumpkin every plant that can be Pumpkined
- Do not use Peas or other single-target plants late-game, Split-Pea included. They will not keep up with the huge number of zombies. Cattails are a possible exception as they can kill at least some Imps that get past your defences to minimise the reliance on Cob Cannons regardless of the lane they're in.
- Try to time Cob Cannon shots so that you kill the Gargantuans before they throw their Imps. In the case of Gargantuans, firing two Cobs one shortly after another at them will accomplish this. (Note Gargantuans may still appear between the two shots, meaning they only take one shot and will then ready their Imp). However, this is considerably harder to achieve with Giga-Gargantuans (need to hit them with two Cobs when they're ready to throw Imps).
An example end-goal layout of endless with 8 Cob Cannons is below (by no means is this exact layout necessary).