"And behold, it was completely overgrown with thistles; Its surface was covered with nettles, and its stone wall was broken down"
What is interesting about this proverb is that it describes all the things that weren't done for this farmer or vineyard owner to be successful. This is the life of the sluggard. Lots of dreams for big money and an easy life, but the small little things that need to be done to get there never seem to be done.
No weeding -- small little daily excuses that allow the thistles to completely take over. If the weeds in your life are not taken care of, then they will eventually consume all of your ability to be productive.
This could be not fixing the little problem that a careless word causes, an errand that was not done, an unresolved conflict with someone, or a compliment or encouragement that is not said. It just allows the weeds to take over so that you have no ability to move forward because broken relationships and mistrust are everywhere.
No boundaries -- it seems like a small thing but the boundaries and edges of your vineyard are not kept distinct and in good working order. When the boundaries of your life are not clear, then your life will become a mess. What kinds of words will be acceptable? What kinds of actions will be acceptable? Will you cut corners in order to accomplish your goals? Will you take time for your family or just let work take over your whole life and hope your family understands. These look like no big deal, but they are big deals and are the mark of a sluggard -- a person who is too lazy to keep the boundaries of their life clear and moral.
Notice that Solomon learned something by what was broken down and unmaintained in the sluggard’s life. It doesn't say that the basic elements of planting were not done. In the off season the thorns and nettles had completely taken over because they had not been out there tending to the small things that they needed to in order to make the field ready for planting when the time came.
What is your field? Have you told yourself that you will gear up for a new promotion, a great family, going back to school when the time comes? But now you feel you don't have to be disciplined and focused. Don't be too sure. It is in the small compromises that the sluggard lets life slip away.