Maybe a spray with a micronutrient mix? Like a Palm nutritional?

Epsom salts works wonders on palms too.

How do I use the salt? Mix with water, or just sprinkle the salt and then water? What proportions?
Thanks,
Sanda

Yellowing of Queen palms this time of year is typical in many parts of SoCal. A good fertilizer like Apex Palm Food will solve the prob.

When I was in San Diego last month, I noted many slightly yellowing Queens, Kings, and Philodendron selloums which I hadn't noticed at all in early trips in Jan - Oct earlier.

I asked if that was maybe due to the low 40F temps in March. I didn't get a definitive answer.

If nutrition is a problem in Feb/Mar and not other months, what causes the problem to be seasonal?

Epsom salts/Mg sulfate can be had in the garden dept of chain stores, but it is not a very efficient way to cure Magnesium deficiency. Apparently not much of Mg sulfate is actually uptaken by the plants. "not much" maybe enough, but most is wasted.

A slow-release palm-specific fert like suggested Apex Palm which also contains chelated minerals is really the best fert for serious palm care. It quickly fixed the "frizzy top" on all the Queens of a friend of mine in Chula Vista who had never cared for his mature Queens.