But they are "capped" at the moment with a wax "cap" on top of their main stems. They are shooting from the sides and bushing up, which is what I want them to do for now, but I am wondering when and how to take these caps off the yucca to allow them to grow.

Is autumn into winter best, or should I let them rest a little and do it in Spring? Also, once the caps are off, should I leave them off of re-apply each year.

Sorry - it may sound like a silly question - I have about 300 or so cacti but have only just started growing yucca!!!

Thanks - Chris

What an interesting way to force them to grow sideways.

I should think that it would be best done in Spring, but, depending on your climate (if you can give it heat and water and sun, preferably all at the same time), most Yuccas are adventitious growers.