To clarify for anyone....I am in Ishad N'ha...the Damn Plants are right outside the gate of Ishad N'ha...there are 4 of them...my highest character is like a 10th level warrior....unfortunately I do not have firestorm and I wish I did. I just want to go to the castle but it is looking pretty slim. I will try the things you all have recommended..Thanks for all the help.
Timult

Let us know what works!

I had the same problem on the first run-through of the game, and was near desperate after reloading 20 times. Eventually, I was able to run past them (without getting caught in the trees) with one character left alive, and a few Restore Life scrolls (you know what I mean, I forget the title). Then I was able to get a few more scrolls in Shurugeon and restore the party. After that, returning to town I moved VERY slowly and hit them with as many distance spells as I could (thrown weapons seem to do little, and binding force doesn't bind them).

One suggestion would be to take your party back to the Serpent Temple or east of the caves and kill things (increase your monster spawn rate) until you gain enough levels for Flamedrop or Burning Haze spells. Really, the Sun spells seem to get them best, although several Fiend spells like Summon Creature or Pain work well too. By the way, I also got whammied by several mantraps waiting for me outside of the stout mines, even though they hadn't followed me there.

And on your next runthrough of the game, beef your characters up early and then hunt the nasty things down.