This plant is dry as a rock

This was said by a friend about a houseplant.  It is a nice mashup of “hard as a rock” (very hard) and “dry as a bone” (very dry).  Bones and rocks are both dry and hard, and are both one syllable words, hence the metaphor mixup.  A big thanks to frequent malaphor contributor Yvonne Stam for hearing this one and sending it in!