I let them callous over for a few days beforehand.
I’ve had a leaf take several week to grow roots, and then nearly a year once in dirt to actually grow a new shoot.
Goodluck!
During the fall-winter time usually it takes months to grow some poor roots on Sansevieria. And some types do this much slower than other in my expirience.
Actually right now I have one Kirkii leaf in water for 4 months, and still nothing.
Growth powder.
I never callus mine. I trim my overgrown ones with a wide "^” shape (upside down ‘V’). I stick them in a jar of water like yours and let it face the sun. Occasionally refill the water and rinse if necessary – sprouts roots like crazy and even further sprouts. Fun fact: they thrive in water!!
I couldn’t get mine to do anything in water. Last resort I just threw them in dirt and bam…got roots. Just recut them and stick em in.
