While we're on the topic of Fiji Dwarf coconuts... I have one in a large rain barrel that's developed what appears to be a potassium (and possibly magnesium, but at least potassium) deficiency - yellowing of older leaves, central vein and extreme edges remain green, then the leaflets begin to wither from their tips. How long after potassium fertilization should the chlorosis stop spreading on older fronds? Should symptoms stop spreading essentially immediately, or is there a delay of days / weeks before you see the effect?
More likely to see the improvement in new/emergent fronds. Could be that they're in Iceland. Do you still have it indoors?
Nah, went and planted it on a glacier
Of course it's inside, hehe
The new fronds have never had problems. Nice perfect new fronds, so it's clearly a mobile nutrient that's the issue at hand at hand - so N P K Mg Cl Mo Ni. K deficiency is said to be the most common problem in palms, and the symptoms match best, so unless there's something else causing K deficiency, adding more K seems to be the presumed solution here. I also did something I've never done before, and goes against every bone in my body - I added some salt to the soil. Our water isn't chlorinated, and I've never used a fertilizer that contains any chlorine, coconut palms reportedly love chlorine, and the occasional watering with saltwater is said to be common and useful in coconut-growing areas... so I winced and added some.
I've historically been rather bad about fertilizer, using the "Meh, that looks good" approach. With "what looks good" generally turning out to be way too little. I'm working to amend my wicked ways