So they went to seed and fell to the ground - this makes no sense. The harvest was related to the 1st century in particular the Israelite kingdom/Jewish nation.
(Mat 13:41 The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity)
The kingdom of Israel is the context of the harvest and the above.
(Mat 13:24 Another parable put he forth unto them, saying, The kingdom of heaven is likened unto a man which sowed good seed in his field)
(Mat 13:30 Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.)
The kingdom/vineyard only applies to the Jewish/Israelite nation of the 1st century:
(Mat 21:33 Hear another parable: There was a certain householder, which planted a vineyard, and hedged it round about, and digged a winepress in it, and built a tower, and let it out to husbandmen, and went into a far country)
(Mat 21:37 But last of all he sent unto them his son, saying, They will reverence my son.)
(Mat 21:39 And they caught him, and cast him out of the vineyard, and slew him.)
(Mat 21:40 When the lord therefore of the vineyard cometh, what will he do unto those husbandmen?)
(Mat 21:41 They say unto him, He will miserably destroy those wicked men, and will let out his vineyard unto other husbandmen, which shall render him the fruits in their seasons.)
The church is the "other husbandmen".