Note:needs high level plants. At least lv6 Primal Potato Mine.
Code:
Circled red=MUSTbe destroyed before using Spear-mint for the first time
Black=first tomb to be busted by Gravebuster
Orange=plant the first Bombard-mint
White=(hopefully Bombard-mint will destroy that tombstone and all the
Red-circled ones, if not) use 2nd Gravebuster to destroy, and then plant a Primal Potato Mine there(lv6+ will destroy all the red-circled tombs)
Green=use the first Spear-mint here. Most of the time, Spikerock will appear on all the tiles closest to the zombies.
Purple=reserve that tile for Primal Potato Mine. If Spikerock appears on it, shovel it.
Hopefully everything will go according to plan.
All red tombstones destroyed. Start planting Laser Beans from the back. Try to spread evenly, but concentrate on one lane if a Bucket-8 bit is making progress. As a last resort, use Mower-launch or Parsnip.
Use Gravebuster to destroy tombstones at the very back(if Bombard-mint didn't do it), and plant Laser Beams in their place. Will deal with any tombstones left in front.
Keep using Primal Potato Mine on the reserved tile, and use Bombard-mint whenever it recharges.(wait a little for zombies to mass)
Keep Using instant recharge on Spear-mint after 35-50secs(depending on its level, recharge&duration).
Plant as many Laser Beans as possible, and you should be successful.(If high level Laser Bean that is)
I use Moonflowers to get a great sun production so that I can spam Parsnip and Lazer Beans. Eventually they all get shovelled up but hey, they're useful for me. Getting scores of around 750k.