I have kept a common pl*co in almost every planted tank I've had and
never seen him even slightly damage any plant. If your pl*c's are
eating plants then they must be seriously starved. The only other
explanation I can think of is that by "tear up" you don't mean eat but
litterally mean tear up. I could imagine that happening. Pl*co's tend
to go wild when they get spooked and the thrashing could potentially
rip some plants to shreds - the solution being to provide better cover
for your pl*co.

Easy plants that I have kept with pl*cos include Vals, Java fern and
moss, Anubias, Hornwort, Frogbit, Duckweed, Anacharis, Swords of
several different types and Water Clover. In addition to these I've
kept perhaps a dozen or so different varieties of more difficult plants
and plants that I no longer remember the names of.

I would suggest one or two large Anubias as the main focus since they
are hardy and rather difficult to rip up with a background of Java fern
which will also be difficult for a pl*co to destroy. Any floating plant
will obviously fair well since the pl*co won't go near them and then
throw in a sword or two for interest and some Java moss for ground
cover. Expand from there if the pl*co doesn't give you any trouble.

If your pl*co really is eating plants then start feeding him algae
wafers on a daily basis and cucumbers at regular intervals. If it is
the spooking that is destroying the plants then add a cave to the
aquarium that is at least as big as your pl*co.

-Daniel