thats one massive and hell-a-tall ponytail you got there!!!

i've had luck both ways. i've got two large (though not as large as your) pontytails. one i went ahead and whacked the head off when it got to tall for my porch. its been a year since then and i've now got three nice full branches. the other ponytail i inherited from my grand mother. it had been in the same pot for nearly ten years!! the pot was huge and i was low on space so i just tipped the plant out of the pot and whacked a third of the roots off the ball with my trusty kitchen knife and re-potted. its been a little over a year since then, and its thriving on a south-facing enclosed porch.

i'm sure others will be able to get a little more technical about it. but my ponytails have seemed to thrive on the very little attention i give them. i only water them maybe once a month. and if i put them in the shower to get the dust off the leaves, i just count that as my watering. i only feed them twice a year, and that's if i remember too.

good luck, that's a gorgeous palm, and hopefully you can get many more years of enjoyment out of it.

Hosta, your ponytail is gorgeous. I've never seen one so tall. Wow.
Fertiling once a year, keeping underpotted, plus pruning roots, may halt its growth some, but you may have to do what Stokes did. It's too nice a plant to give away. Cut back 2/3rd plus roots. I've no idea how you haul it around to clean and/or take outdoors. No wonder you have back problems..LOl. Keep it going, Toni