The parable of the seed and the parable of the mustard seed

The parable of the seed taken from Mark 4:26–29, using the NIV;

26He also said, "This is what the kingdom of God is like. A man scatters seed on the ground. 27Night and day, whether he sleeps or gets up, the seed sprouts and grows, though he does not know how. 28All by itself the soil produces grain—first the stalk, then the head, then the full kernel in the head. 29As soon as the grain is ripe, he puts the sickle to it, because the harvest has come."

The Mustard Seed, taken first from Matthew 13:31–32;

31He told them another parable: "The kingdom of heaven is like a mustard seed, which a man took and planted in his field. 32Though it is the smallest of all your seeds, yet when it grows, it is the largest of garden plants and becomes a tree, so that the birds of the air come and perch in its branches."

And then from Mark 4:30–32;

30Again he said, "What shall we say the kingdom of God is like, or what parable shall we use to describe it? 31It is like a mustard seed, which is the smallest seed you plant in the ground. 32Yet when planted, it grows and becomes the largest of all garden plants, with such big branches that the birds of the air can perch in its shade."

And finally Luke 13:18–19;

18Then Jesus asked, "What is the kingdom of God like? What shall I compare it to? 19It is like a mustard seed, which a man took and planted in his garden. It grew and became a tree, and the birds of the air perched in its branches."

Jesus told both these parables at the same time, according to Mark's gospel. I'm really not sure what to make of this one. I think the parable of the mustard seed talks about faith, how it takes a small "seed" to help someone find christ, but faith grows to become powerful and so on?

As for the first parable. Eh, I guess it's talking about the end time. Christ will return to "harvest" his followers when the time is ready?

I'm afraid I'm pretty useless today. Sorry.