Sounds about right to me. When I had my robusta, it got to about 5 feet tall, but only held about 5 fronds at a time, just as you described, yellowing the oldest one just as a new frond opened.

I now have 2 smaller filibusta crosses, both about 2 feet tall, both can hold about 8 fronds or more at a time. I think the small number of fronds they hold is due to being rootbound. Even in very large pots, they root like weeds and quickly fill out their root space. Seems inevitable to me unless you plant it in the ground.

Hi. I have some robustas growing in my neighborhood that only have a few fronds. Conversely, there are trees that have many fronds. I believe the trees with few fronds may be recovering from Winter damage and perhaps grow only 3 fronds over the Summer. However, perhaps they may have been trimmed by the town. I haven't lived here a year yet but I have seen other town's street palms have been trimmed. Here are some pics of trees in my neighborhood.

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Your problem sounds normal for a potted washy of that size, Get that palm in the ground and it will green up.

Hey Bob, looks like those washys were all trimmed like that.
Many arborists cut too many of the leaves off. Doesnt look good and isnt good for the palm. Just a way for them to make money by claiming its good for the tree. :P

Thanks,

I put it in the ground in November. There are a handful of robuastas around here that survive wthout any winter protection, but usually look pretty ratty or completley de-foliated depending on how low the temps go. I placed it in the most protected spot I could that still has full sun. Sadly, this spot is also the most hellaciously clayey place in my whole yard. I got sick of lugging it around the patio and figured I would give it a shot it the ground. I'm hoping it won't be too angry about the lack of drainage, since I have seen pics of them growing in (or very close to) standing water. Maybe this year I will see some of the "fast" growth they are known for.

Update:

It is much happier now that it is in the ground, It has kept all 4 of it's old leaves from last summer year, and is about to already put out it's 5th leaf of this spring. I am looking forward to seeing how big it will be by November this year....