I don't know if this is common knowledge, but if you prep the Titan Guitar, it will destroy all the walls on the level on start. This can be crazy powerful with a prepped earthmother. I can easily get 11 or 12 shots of vine form or greenblood on pretty much any map this way, and as a side benefit, the titan guitar slows everything when you use it, so you can even get xp when you petrify enemies!
The disadvantage you get from prepping earthmother is even helpful in this situation; during the end game you have plenty of piety and plants to fuel many clearances (and those fireballs are especially painful to an enemy with 12 layers of corrosion, aren't they?).