Level 1: Day Time Part level, part tutorial, the number of lanes expand as you go through the levels as do the plants on offer. You’ll need at least three sunflowers for all levels. But grow as many as you can. Use the Wall-nuts at the top of the lanes to stall the zombies for as long as possible You’ll need at least one Pea-Shooter per lane, preferably at least half-way down the lane. When you get the Snow-Pea, you’ll need one per lane as well.
Level 2: Night Time Use your free mushrooms!! Get as many in each lane as you can while you get a row of sunflowers and sun-shrooms established. Don’t forget your Wall-Nuts, right end of the lane – Stall those Zombies! You’ll need a FumeShroom, at least one per lane and at least two peashooters and two Snow-Peas per lane. Use Ice-Shrooms to defeat the Disco Zombie. Keep a grave buster on hand, those graves keep taking up more and more space.
Level 3: Pool Don’t place sunflowers on lily-pads, keep them on the lawn – again aim for eight. Don’t start filling in the pool with lily-pads straight away, the water zombies don’t start straight away. Use your Wall-Nuts, on the lawn and in the pool! You’ll need at least two peashooters and two snow-peas, per lane, even in the pool. When available, you’ll need a cactus in each lane too. In the water, fill up with lily-pads, it does slow the zombies down. Tangle weed is also very effective but can only be used once.
Level 4: Fog Welcome to the real dark. The same grid pattern applies – but you have to be a bit more trusting of the grid and listen carefully! Planterns are reasonably cheap and long-lasting… but they can be munched through by zombies. Defend with a Wall-Nut and build your grid up as much as possible. Blovers are instant and reasonably long lasting – they can’t be munched through – but the effect wares off. Use your free mushrooms as much as possible to start a good line of defense. Keep growing sunflowers to get as much sun as possible. You’ll need at least two pea-shooters, two snow-peas and a cactus per lane. Triple Pea are very effective, as they fire in to three lanes and the Split-Pea is a necessity – the moment it becomes available, add it to your arsenal. The Split Peas are also very useful – they can be installed after a zombie has passed a square and still be effective…also the mining zombies work backwards and these are the only things effective against them.
Level 5: Roof Here you need to place pots as well as plants. Try and get as many pots on the grid as possible in the beginning – like Lily Pads they also slow the zombies down. Again, defend from the right with Wall-Nuts then fill in with ‘pults’ starting halfway down the board. To start you’ll need one cabbage-pult and one  kernal pult per row, but pretty soon you’re going to need two and then three. Where the roof flattens out (on the far right), you can use pea-shooters and snow-peas. Do it!! At least one per lane. Watermelons are expensive, but very useful, try and get one per-lane, but it can be done with just cabbages and kernal-pults.

Finale:

• Set out like a mini game you don’t have to worry about stockpiling sunshine – you do however have to make use of what comes along the conveyor.
• The same strategy as always applies, keep as many ‘pults’ in each lane as you can – the more even the better.
• Try and keep one pot free per lane, or be prepared to dig up a plant quickly to replace with a Jalapeno or Ice-Shroom. You’ll need these to defeat the large balls of ice and fire produced by the Boss.
• You’ll know when one is coming, because the robot (and mad scientist) will lower his head down to the roof. He’ll either snort fire or snow, a good indicator of what’s coming, then you have to wait and see just which lane he’s aiming for…get in early and fast – you won’t have a problem.
• Keep replacing the pots and the ‘plants’ as they get smashed etc, and always have a Jalapeno or an Ice-Shroom on hand. The finale is all about getting through to the end, eventually the boss runs out of steam and crashes…leaving you and your brains alone.