All luggage is inspected at the airport by the United States Department of Agriculture. From their website, here is a partial list of items that can NOT be transported from Hawaii to the Mainland: Items from Hawaii Not Permitted into the U.S. Mainland: Berries of any kind, including coffee berries and sea grapes Cactus plants or parts Cotton and cotton bolls Fresh flowers of gardenia, jade vine, and Mauna Loa Fresh pulpy fruits and vegetables (except pineapple) Kikania and fresh pandanus Live insects and snails Plants in soil Seeds with pulp and fresh seed pods Soil Sugarcane Swamp cabbage (unchoy) Sweet potato (raw) Looks like the prohibition on transporting soil is going to be the one that ruins your plans. Sorry. -Steven