Just keep watering to a minimum, but don't let soil dry out completely. Spindle palms are tender plants so the soil temperature should not fall below 60F for extended durations. Make sure palm get adequate sunlight. To make a better diagnosis a photo would really help :).

DO NOT LET THE PLANT SIT IN THE SAUCER FILLED WITH WATER!

Hyophorbes seem particularly susceptible to browning of the leaf tips as a result of fertilizer salt re-uptake, which occurs when drainage water sits there. Figure out how to get rid of the excess right after watering. I prop my pots up on a brick so that the drainage water is separated.

Another way that the fertilizer salts become problematic is if you do not water enough. If slow release fertilizers are in the soil, they require a periodic leaching by watering enough that there is excess drained out the pot. If this is not done regularly, brown tips will also be the result. So every time you water, do it thoroughly. If you have a good soil mix (another topic that would take too long to discuss), there should not be an issue with regular watering unless it is cold. Aeration/ oxygenation is the key.

Lack of light and cold weather will lead to stunted new growth. It should not effect the existing leaves.

How do I know these things? Well, I have the same plants which had the exact same problem. Older fronds had brown tips that were gradually spreading. I thought it was too cold. I thought there was inadequate light. Once I started drenching the soil regularly with the pot elevated from the saucer so that the roots cannot reabsorb the drained water, the problems have gone away completely.

I also believe that acidifying the water with some vinegar may be beneficial. But the "science" behind this is questionable.

x

I only water mine at the most 1 time a week and not very much water then.