Steven,
If the plant that is browning has already flowered then that is normal. After Bromeliads flower the mother plant SLOWLY withers away.
If this is the case, then removing the pups depends on a couple of things, the species of bromelaid and their roots.
The pups you say are a 1' tall already, normally that it is a good sized pup that sounds like it's ready to be potted up. However, some of the larger bromeliad species will have pups that big that are not yet ready to cut off yet.
Look at the base of the Brom, where the pup meets the main mother plant (You might have to pull down the leaf directly under where the pup is coming out of to see). Check and see if the actual pup is producing roots yet.
If the actual pup has roots, it is ready to remove and pot in it's own pot. Not all pups develop at the same rate so check them all before proceeding.
To remove the pups, you can use a saw but I prefer to just use a heavy duty garden branch lopper. Which ever you use, make sure it can make a clean cut as most broms can be tough to cut as the stolon is very thick usually. Cut as close to the mother plant as possible, it is actually ok to shave off a slither of the mother plant with the pup as this ensures you don't cut the pup too high and damage it!
Once the pups are removed you can apply a fungicide/rooting hormone top the cuts part of the pup if you desire - but honestly it is not needed, even though not a bad idea. I sometimes powder the cut part, but usually don't. Pot the pup up with water soil mix you currently use for your broms and water well, make sure to fill the vase.
Now the mother plant will do 2 things, it will either produce more pups now that it is no longer supporting the pups that where cut off, or it wont... Either way it will eventually wither away. That is of course if it is an already bloomed brom, which it sounds to me like it is
Hope this helps, and have fun Chopping!!
Warmest Regards and Happy Growing,
-Jc
Miami, Fl
