Yes, they reseed themselves.
I would think around the end of autumn when retailers need to make room for winter items.
Spring
For a nine year old I would only recommend doing lawn maintenance, during the summer and weekends during school-time. That is only if the nine year old is able to understand the responsibilities involved. The best bet is to have the child cut his family's grass to begin with and to study books from the library on lawn maintenance.
I have seen pretty good prices for riding lawn mowers at Sears and Lowes. I recommend checking the consumer reports to find out the best riding lawn mowers, I bought one and it broke in a year so be careful with your pick.
The best time of the year is July
The best waterproof and weatherproof materials are the ones that say waterproof and weatherproof on the packaging. Then you can leave your lawn furniture out all year long.
Babysit or help neighbors with lawn chores.
Every year my block has a contest for best lawn. I want to do something special this year. Is there a website that offers landscape design?
form_title=Lawn Maintenance Services form_header=Lawn Maintenance services brings you the expertise your lawn needs to look its best year round. How often would you like your lawn maintained?=_ Does your yard currently use underground sprinklers or above ground?= () Underground () Above ground How often do you water your yard?=_
Actually there are different seeds available for different times of the year. You can find seeds best used for winter/fall growth or spring/summer growth. You can check at Home Depot or Lowe's in the garden department.
Babysitting, lawn work, newspaper routes, and working for relatives are your best options.