I wouldn't DARE put a higher nitrogen fertilizer on my inground fig trees. They, especially the one out back, would try to take over the whole city.Maybe it only applies to the Southern regions of the country because it's warmer and the growing season is longer and the trees have more time to put on growth compared to how they do in the cooler parts of the country.
I saw what happens with higher nitrogen fertilizer the two years Mike tried to murder the two Celestes with lawn weed and feed. First, the weed killer socked the two trees so hard all the leaves wilted back and I thought the trees were dead, for sure. But then the feed part got to them several days later and the trees came back and shot up like they were going to go into orbit. No figs started and the node spacing was huge. The trees only got figs later in the season and not very many of them.
I told Mike that it was the weed and feed that did that to the trees and he refused to believe me, so he repeated the same regimen the next year, after the larger Celeste had been planted out back inground.
That tree had been in a pot the season before, when the weed and feed first hit it. After that, it had literally burst out of its 5-gallon pot and planted itself into the ground and had gotten some amazing trunk growth toward the end of the season, so it was pretty hefty by the time it was transplanted out back. (It wouldn't stop growing. Even so, it never froze back anywhere over the winter.)
So Mike, again, put weed and feed on the lawn in front and back and guess what happened? I told Mike that it was the weed and feed and he got so mad at me I wanted to kill him. I was convinced he wanted to murder my trees so he didn't have to mow around them.
The following year, I cried at him and asked him to please not put that weed and feed anywhere near my fig trees, told him, again, that fig trees put roots all over the place and that's why the weed and feed affected them. I told him to just not do it that year. So he didn't put any weed and feed near the trees and they did beautifully, which was proof enough to him that that stuff needed to be kept away from the trees. Then he felt badly about the trees.
The tree out back was all messed up for several years and I didn't think she was going to make it, but she did.
I know the lawn feed had much more nitrogen in it that a higher nitrogen fertilizer for plants would have and the trees had an exaggerated reaction to it, but for inground trees, I wouldn't want to put a fertilizer on them with even just 3-2-1. I don't want to chance that when they put on such lush growth without it.
I would think that trace minerals would also be good for inground, or potted trees.
This is just my opinion after my experiences with my trees.
I've read that fig trees are nitrogen-sensitive and I think they just might be. It might make a difference because fig trees are semi-succulents.
I saw what too much nitrogen did to my trees and it did indeed delay fig production and ripening. I saw this for myself.
Potted figs may be a different story as to the fractions of P & K building up in the soil after the N is used up.
Sometimes what people think SHOULD be, on paper, and what IS, are two different things.
What's sauce for the goose may not always be sauce for the gander when you look at the vast expanse of this country.
Balanced fertilizer might not work for cooler regions of this country.