Annual crops in the kingdom of God

Jesus repeated the use of seeds in other parables.

In the Gospel of Mark only, Jesus told a parable describing how we sow seeds, having no understanding of how they grow, and yet we sow expecting to reap a harvest.

"And He was saying, 'The kingdom of God is like a man, who casts seed upon the soil; and goes to bed at night and gets up by day, and the seed spouts up and grows - how he himself does not know. The soil produces crops by itself; first the blade, then the head, then the mature grain in the head. But when the crop permits, he immediately puts in the sickle, because the harvest has come."
Mark 4:26-29

The point of the parable is that, in the kingdom of God, the word grows on its own, without our efforts. The investment cycle begins with sowing seed; in the course of growth no seeds are to be found. What was just a seed in our hand becomes something very different, very not seed-like. But in time, new seeds are seen in the mature grain. It is then the time for harvest; the investment cycle is completed when the word that we sowed in the beginning has been replicated fully.

This is part of doing business with the riches of the kingdom of God. We don't have to understand how the word can grow in a man; we should just expect it.