May I propose an alternative interpretation of this parable. When the our focus is turned inward and we become more focused on the progression of our own soul and not the righteousness of those outward I believe we can see this parable slightly differently.
The "enemy" does not have power to sow any souls. Could not this parable mean that God plants us in mortality, and the good we have in us, and as with opposition in all things, the enemy is allowed to plant within us tares. God does not cut us off, or dig us up when the tares are perhaps at their fullest in our lives, but rather allows us to continue to grow and live through maturity. As we grow, progress, and repent we approach maturity and the end of our lives at which time, or thereafter, it matters not, the atonement baptises us with fire and the tares of our imperfections are burned away. It is in this interpretation I find the greatest mercy and grace of the Savior. But perhaps that is merely only that which I alone am looking for and not the more generally intended interpretation of the parable.
Nonetheless, it is for you all to ponder in your hearts.