Yucca trees - straying from the subject.

by Jo
(UK)

I know this page is primarily for vegetable gardening, but can anyone help on this problem of mine.

I inherited an enormous Yucca tree when I moved here. Last year it produced five very large flower spikes - each about 18 ins. long. This year there are eight flower spikes.

My question is do I leave the old spikes where they are? It would difficult to remove them - needing a ladder and fighting my way in to get to the source of the spike amongst all the other spikes which have nasty tips.