Subject of what to do about lower leafs on a Jubaea Palm that is browning up or dead but won't fall off has been discussed many times. But recently I have realized after doing a little experimentation, that it is best to leave a dead leaf on the trunk until if falls off on its own. If a dead leaf is cut leaving a stub behind, the stub will persist for very long time often many years. But if the dead leaf its allowed to remain it will fall off much sooner than if cut to stub. Reason for this is the dead leaf is constantly pulling away from the trunk from gravity much more so than a cut stub, allowing for the attached fibers to break one by one until there is nothing holding the leaf to the trunk.

Forcing a leaf or stub away from the trunk should never be done, because it increases the chance of infection entering the wound. The Jubaea prepares in advance of a natural leaf breaking away from the trunk by retreating living tissues in the scar area so that when the leaf suddenly breaks away the wound it is already mostly healed and ready to harden off.

The same principle probably applies to many other Palm Species with normally smooth trunks. Climate, health and other factors do influence whether a leaf will break away from its trunk cleanly but trying to force a leaf or stub off the trunk is risky to the health of the palm.

Not always true.

Trimming leaves is purely for aesthetic purposes in most gardens, any amount of life left in a palm leaf will benefit the palm, no matter how tattered or dying look, the palm needs that leaf right up until it decides to drop it. Leaves are a factory for all plants, it’s only us palm nut fanatics who go crazy with the secataures or pruning saw, I pretty well much leave them on until they fall off. There are some exceptions to that rule a problem leaf rubbing against a roof or building, a leaf that is in the way near a pathway, transplanting a palm you remove a lot the foliage. A leaf that is in danger of doing substantial damage if it falls. But in general wait until it dies and falls off.

Most of us grow palms for their aesthetic value and for me and many of us, dried up brown persistent fronds are a detriment to that. A lush green garden versus one that has lots of dead hanging foliage, hmm, which one do I want to look at and be in? Fortunately most of my palms are self cleaning but many, such as Parajubaea, Livistona, Syagrus, Trachycarpus, Phoenix, and others are not so I trim off yellowed leaves. Rhopalostylis, on the other hand, often shed their oldest frond while still green and quite heavy. The stems and old boots of virtually all the palms that are trimmed here, fall off readily, many right up near the palm’s canopies with just a few exceptions. I don’t think leaving the dead fronds hastens trunk “cleaning” appreciably.

@Banana Belt I see this a lot with local Sabals. The ones in natural forests here are usually full crown but all the fronds below about halfway down are dead and crispy brown. But they fall off complete with the boot in time and leave a completely smooth trunk. Only the Sabals in people's yards still have boots, for the most part. It's probably because people cut off the frond and then gravity doesn't pull the boot off, like you said.

I routinely cut off brown or cold-damaged fronds for cosmetic or clearance issues. But I try to not tear off boots until they are ready to fall off. If I'm pruning stuff and the boots just peel off easy then I'll peel them off until I find one with some resistance, and stop there. The only exception is stuff like a Bottle palm, where I use a razor knife and super sharp shears to carefully snip off the old boots. I might clean up old boots on a Bismarck or Alfredii for similar cosmetic reasons...and because the giant flying cockroaches ("palmetto bugs") love to live in the rotting old boots...

3 hours ago, Jim in Los Altos said:

Most of us grow palms for their aesthetic value and for me and many of us, dried up brown persistent fronds are a detriment to that

I completely understand and find myself wanting to make the palm look better. Dead brown hanging leaves are ugly.