Question
Hey, Mike;
I hope this is fair question to ask of you. In building a small elevated garden (above grade, enclosed within six (6) railroad ties [two on each side, one on each end]) is it necessary or of any consequence to remove any of the original soil surface before filling the enclosure with top soil? Shouldn't topsoil the depth of the thickness of the railroad ties be sufficient to provide anchorage, nutrition and moisture for tomatoes, carrots, peppers and other common garden vegetables? If not, what do you recommend?
Thank you very much.
Gene Michael
[email protected]

Answer
Raised beds should be a minimum of 8" high.  It is advisable to turn over the existing soil prior to adding topsoil.  A secret I learned long ago is to cover the existing soil with 2" of newspaper.  The thickness of the paper prevents weeds from growing, and the paper slowly decomposes, adding carbon to the soil.

I would also recommend adding as many organic supplements as possible.  These include peat moss, compost, aged manure, dried grass clippings, and shredded leaves.  These materials will improve the tilth of the soil, improve drainage, and still retain the proper amount of moisture needed for strong root development.

Good luck, and please write again if I can ever be of assistance.

Regards,

Mike