Q.My granny used to water her houseplants with cold black tea to feed them &her plants always looked healthy; is this ok to do?
My spider plant is now growing small plants; I believe they are called babies; how do I root them so they can be transplanted?

Certified GKH Gardening Expert
I didn't find any research that supported watering plants with cold tea, but the used tea leaves or teabags can be added to the compost bin or worked directly into the soil around plants for improved soil drainage and structure.
You can easily propagate new plants from the spider babies and instructions are below.
https://www.gardeningknowhow.com/houseplants/spider-plant/propagating-spiderettes.htm
https://www.gardeningknowhow.com/composting/ingredients/composting-tea-bags.htm