Not every yellow frond means trouble
Palms naturally shed their oldest, lowest fronds as part of normal growth, and some yellowing on those bottom fronds specifically is expected. The pattern that matters is whether yellowing is isolated to the oldest fronds (likely normal) or spreading upward through the canopy (worth investigating).
Lethal yellowing has a specific pattern
This disease typically starts with premature fruit drop, followed by yellowing that begins at the oldest fronds and progresses upward through the canopy over weeks to months. Once it reaches the growing point at the top (the bud), the palm generally can't recover.
Nutrient deficiency looks different
A palm short on potassium or magnesium tends to show frizzled, discolored new growth at the crown rather than the oldest-frond-first pattern of lethal yellowing. This is often correctable with proper palm fertilizer rather than removal.
Overwatering is a common, avoidable cause here
Palms planted in the same irrigation zone as lawn or flower beds are frequently overwatered, which weakens root health over time. If your palm is struggling and sits in a zone watered for grass, that's worth checking before assuming disease.
When to call for an assessment
If you're seeing upward-progressing yellowing, premature fruit drop, or a stalled growing point, it's worth getting a professional look before deciding between treatment and removal — the visual difference between recoverable stress and lethal yellowing isn't always obvious from the ground.