I'm just dumping the soil outside on an area with some trees. There's some bare soil anyways, and it is on a hill. Figure that since I put a lot (too much) compost in it, should do good things for the trees. The plants themselves are going in the dumpster. Probably the guru's can answer this... Would it make a difference if the containers with tomatoes were right next to the containers with the old soil? They might get splashed while watering. Alice

First, do you know for sure you have lead contaminated soil? Have you had a soil test done that measured heavy metals? Often, in areas that once supported heavy industry that did generate lead contamination, there is far more atmospheric and residual (surface) contamination than soils that are seriously compromised. And the lead problem can be made to go away. Biologically active compost is used extensively for bioremediation of all sorts of toxic and contaminated soils and it is cheap, relatively rapid and very effective. There is also no documentation that supports that lead in excessive levels is necessarily transported into the plant tissue and subsequently to you as the consumer of the plant parts. The greatest risk is exposure to you through working the contaminated soil and its dust or tracking it into your house, etc. So there is really no need for "bottoms" to your raised beds, although container growing is certainly an option. Sterile potting soil is just that - it has been pasturized or heat treated to eliminate pathogens and is used primarily for seed germination. The "organic" component is the ingredients in the mix, often peat, sometimes bark fines or other, non-soil organic components. The microbes typically present in any OM have been killed off by the heat as well - the pasturization process doesn't distinguish between the good guys and the bad guys :-)) But that doesn't necessarily mean your seedlings will starve for nutrients. Seeds are plant embryos that contain all the nutrients necessary for germination and the development of the first true set of leaves. It is not until these leaves emerge and the photosynthesis process begins that seedlings are even able to access soil nutrients. And pasturization or sterile potting media doesn't necessarily eliminate nutrients - these elements will remain in place in some quantity regardless. Once the seedlings have started producing true leaves you may, however, want to start supplementing with a dilute liquid fertilizer to ensure they are getting everything they need. And it is at this point in time you can consider potting them up into larger containers with a non-sterile potting medium, as the greatest risk of damping off or other fungal problems that affect seedlings has passed at this stage of growth.

...if you are near the ocean... And even if you are not. I can set up a saltwater aquarium here in MN, and it will quickly become populated by algae whose spores have been carried by air currents all the way from the Pacific Ocean. It's really amazing how much stuff is just floating around in the air. I have to agree that any sterilization is only momentary. Good cultural methods will prevent inevitable pathogens from taking over. What little seed growing I've done has been with a gritty soil and substantial air circulation in order to prevent the wet, stagnant conditions that allow pathogens to thrive. And the Opuntia pads we're talking about here are mature growth that is much less susceptible to pathogens than seedlings.

Thanks for the reply Pit. When I didn't know any better (last ywo years), I potted rooted cuttings in soil dug up in my yard. It is mostly forest type topsoil, since I live in the mountains and have large pine trees in my yard. All my plants look very healthy but I now start all new cuttings in store bought topsoil. I'm having 5 yards of premium topsoil shipped up from a Sacramento wholesale nursery. Supposedly, it is top quality. I will be potting many hundreds of 1 gallons into 5 gallons this fall. FF