“‘The time of figs was not yet’, says Mark, for it was just before Passover, about six weeks before the fully-formed fig appears. The fact that Mark adds these words shows that he knew what he was talking about. When the fig leaves appear about the end of March they are accompanied by a crop of small knobs, called taqsh by the Arabs, a sort of forerunner of the real figs. These taqsh are eaten by peasants and others when hungry. They drop off before the real fig is formed. But if the leaves appear unaccompanied by taqsh, there will be no figs that year. So it was evident to our Lord, when He turned aside to see if there were any of these taqsh on the fig tree to assuage His hunger for the time being, that the absence of the taqsh meant that there would be no figs when the time for figs came. For all its fair show of foliage, it was a fruitless and hopeless tree.” (F. F. Bruce, The New Testament Documents: Are They Reliable?, p. 73-74)
Ah, that explains it. When Mark wrote ‘the time of figs was not yet’, it didn’t mean that Jesus was unreasonable in expecting something to be eaten from the tree when ‘the time of figs was not yet’, but precisely he should expect some taqsh to be there to be eaten.