Parajubaea cocoides question

[Sean Osborne]

I recently became caretaker for my father's place in Santa Barbara, including his palm tree collection. I have a question about the growing habits of the mature specimens. 

Below is a pic with a trio of Parajubaea cocoides on one side, and a single P. cocoides on the other. The trio is 15-20 years old, and has the classic hairy-looking trunk. The bottom 10-15 feet or so are smooth, having dropped the frond bases entirely, but from there on up the trees are holding tight to the remnants of the dead fronds.

The single P. cocoides on the right is well over 50 years old. As you can see, the trunk is smooth almost to the top. 

It appears to me that P. cocoides begins shedding its fronds as they die once it reaches maturity. I really want to be right about this. I want someone to say "that's right, you won't need to trim the older tree at all, it will simply drop its fronds like a King palm."

Because that would mean that I have one less really tall palm tree to trim.

Does anyone know what these trees are like at this age?

[tim_brissy_13]

I’m 99% sure you’re right. I’ve never grown Parajubaea to that size, but online images of very old ones show clean trunks. 
 

This is common to many species. Washingtonia robusta is a really good example. Old tall ones are clean while younger ones have retained leaf bases (and fronds if not trimmed). What I think happens is as a palm reaches maturity, its trunk girth stays uniform and doesn’t expand much after the crown is developed like it would when it was younger. It’s this expansion that locks leaf bases together. Happens clearly in Dictyosperma and Hyophorbe too. 
 

I’d suggest not trimming the fronds will actually speed up the process because leaf bases are more likely to fall with fallen fronds from wind. 

[quaman58]

Beautiful looking palms once they shed the old leaf bases. Very few around here reach that age for some reason. My neighbor has one that’s 20-ish years old. He’s come close to losing a few times to infection, but it’s always responded well to treatment. Although his is seeding, it’s still holding on to the leaf bases and fur on the trunk. Tim’s observation of of similarity to Washingtonia makes sense to me. Beautiful palms!

[TropicsEnjoyer]

I’m not in a position to answer your question but I must say those palms look spectacular. I love that trio, and honestly the trunks look good with or without the old leaf bases. This is another palm that I’d love to grow if it wasn’t so big haha.

[Darold Petty]

Here are two from Otavalo, Ecuador.  My adult plant died before shedding much fiber.

[Jim in Los Altos]

My 18 year old torallyi recently began dropping old leaf bases. Not super smooth underneath but I imagine over time it will be.