when is the last time you changed the media???

media does not last forever ...

and is the pot black on the bottom.. or is that an indication of a water problem ???

i would NEVER have trees.. that large.. in that small a pot .. in full sun ... and i am halfway to the north pole ...

i think you have a water management issue.. which may also be a nutrient issue ...

but unless you solve the media issue.. dumping fertilizer in.. wont help ...

lets see what the others say ...

ken

ps: coffee buzz.. but arent these houseplants ... ?? .. meaning he is growing a plant that can cope with very low light.. in blinding Mexican sun ....??? ... i feel i am missing something obvious.. and blame it on the coffee .. lol ..

Judging by the size of the chair in the picture, the pot isn't that small. Ficus microcarpa can be grown inside, but is a common (and invasive) street tree in tropical locations. It's a good candidate for container culture and is a favorite bonsai specimen.

You do need to answer questions about your potting medium (medium is singular.....media is plural of medium) . Does it drain rapidly, do you know what the ingredients might be (peat moss, petlite, and bark fines are typical), is it coarse textured or silty, is it tightly packed?

I don't know what the yellow spots are. Is there anything on the back of the leaves? Nutritional disorders can be common with plants struggling in poor quality, compacted, or poorly drained soil.