I have a grafted cactus that I picked up at Lowes on the discount shelf. The bottom portion or the rootstock had a gash in it. It has since turned brown and squishy. It can't support the top part which appears healthy. What can I do at this point to bring it back or at least save the top?
I Have a Grafted Cactus I Am Wanting to Save
When a cactus - or any plant, for that matter - is brown and squishy, it's dead, and there's no saving it. You might, however, be able to regraft the yellow top onto a new cactus. It has to be grafted because it has no chlorophyll so it can't make it's own food. This article will help you with that project: https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/grafting-cactus-plants.htm