Question
I am about to create my first vegetable garden, ever. I am a converted organic locavore! I want to use a spot in the lawn in a good sunny position. However, I don't know the history of the lawn. Should I cover it with plastic and then place soil over it? Is plastic a problem in terms of organic? How deep should the soil be? Do I have to go to the trouble of testing the soil (beneath the grass)?

Answer
Dear Michael:

Congratulations on becoming an organic convert!!  You can use a sunny spot in your lawn and dig.....or, perhaps you should consider raised beds. Depending on how large the plot will be for your garden, the use of a raised bed provides much convenience.  Using 8 feet long landscape timbers and stacking them 3 or 4 high and using either large nails or L-shaped metal brackets to secure the corners with screws or smaller nails.  Fill in the newly created bed with bagged soil available from your garden center store.  The link below will provide you would more information about raised bed gardening:

http://extension.missouri.edu/explore/agguides/hort/g06985.htm

If you decide to dig directly into the lawn, I suggest you consider filling the cavity with bagged soil unless the existing soil is very fertile and/or of the sandy loam variety.  If you plan to use existing soil, then mix in organic materials such as compost, greensand, or cottonseed meal.  Dig to a depth of 18 inches or deeper.  Lining the bottom of the cavity with plastic sheeting is optional and could deter proper drainage.  Soil testing is optional and likely you may want to wait until next season to test it.  I hope you have a compost pile or plan to start one since this will provide you with a steady supply of organic material to make your garden grow.

Best wishes for your success.

Sincerely,

Mack Jean
AllExperts
Master Gardener
Tennessee