I’ve planted them several times. Last year they grew, but not enough to produce any sponges.
They’re handy as disposable, compostable scrubbing sponges, for dishes or skin. They’re on my list of non-edible-but-important survival garden plants, alongside things like soapwort and pyrethrum daisies.
But in my area, they apparently needed to be started earlier than when I started them.
Sometimes temperature can stunt growth if too hot or cold................