Would you work outside for a handful of hours and receive thousands of dollars? I would!
I can't tell you how many houses I have shown to potential buyers and they are instantly turned off by the neglected landscape or the poor condition of the front of the house. There have been times where they don't even want to get out of the car! I even had buyers walk up to the house to instantly turn right back around to the car. If the front of your house is messy, more than most likely the inside is neglected too. The front yard is the first impression of the rest of the home. When driving up to the house, you want buyers to have a warm, welcoming feeling and experience as to how it would be to live there. Having a negative feeling before they even walk in the house is not a good first impression.
Spend a weekend or 2 (depending on how bad it is) mowing the grass, pulling weeds, laying mulch, digging up dead plants/trees, etc. It's worth it. Trust me. Ask a neighborhood teenager to help or do all of the work. Being a high school teacher, there are many students who would even volunteer to help local families with yard work. Same with pressure washing the house and driveway. Just ask! Also, don't forget to put away items that are not necessary in your yard - buckets, pots with no plants in them, yard tools, kid's toys, garbage, dirty diapers...yes, unfortunately, that has happended.
Your goal is to not make it immaculate and spend hundreds to thousands of dollars. Start with the front yard and work your way to the back and sides of your home. Just like you would clean the inside of your house, clean the outside. AND do it on a weekly/biweekly basis.