Not only pest resistant, it is freeze resistant. I have it on the pond tray for my koi pond (formerly my tilapia pond and my catfish pond) and my friend the aquaponics expert was telling me how you can't do anything aquaponic in the winter in Texas unless the pond is in a greenhouse, and I showed him my green and red swiss chard. I grow it because my grandmother grew it, but also because spinach does so badly in Texas