g'day andy, as it is a storm water drain, which takes run of from streets and footpaths as well as other homes, i wouldn't be too concerned especially if you grow mostly above ground crops like the fruits and brassica's etc.,. then with root crops ensure they are properly washed for eating if they get cooked then i'd be thinking that would negate any other things as most what you talking abut would be adhere to the outside of the food. whatever may be in the storm water comes from the air mostly so is here when it rains down on your garden. len Here is a link that might be useful: lens garden page

Hmmm. No one ever talks about the microbes. Microbes make top soil unique - definitely not the same as sub soil. Microbes act as the interface between the organic material in soil and the plants. Plants will suffer in sterile soils, not matter how rich the soil is, without microbes - unless of course, the soil is treated with synthetic fertilizers and/or hormones. Plants in soil without microbes (and no fertilizers) will essentially starve. Dirt is not an appropriate synonym for top soil. The two are quite different things. Top soil is almost impossible to store, as the microbes require oxygen. The oxygen only penetrates a few inches in the best of soils, to about 8 inches max. Heavy soils can have top soils that are only fractions of an inch deep, or even none at all. Deprive the microbes of oxygen, and the microbes die in hours. Plastic-bagged, manufactured top soil, will not have appropriate conditions for microbes to survive if they were ever present. Even true top soil, if harvested through grading and stored in piles, will only be true, healthy top soil on the top few inches of the mound. Within hours all of the microbes below the top layer of the mound will have died. True top soil is a living thing. Top soil needs to be harvested and properly placed in a very short period of time. Take a yard of dirt (or at least a good pile) from below the top soil, mix it with fertilizer-free compost, mound it up in a remote area of your yard and watch what happens - nothing. Nothing will grow on that pile, even though it is dirt amended with compost, because it essentially sterile. After one to two years, the microbes will begin to permeate the top layer of the pile and plants will start to show up. With true top soil, the mound would explode with plants after the first rain. Manufactured mixes "cheat" by stuffing the created mix with fertilizers. This works, but is lousy for the environment in many ways, and "hooks" your plants on synthetic fertilizers like drugs. When you hear such names as Monsanto, Miracle Gro, etc. think "pusher". Microbes do not like synthetic fertilizers, so once using fertilizers, you are stuck using them unless you do a lot of work to fix the situation, or wait until the soil regains a proper ecological balance. Plants will grow well in many types of media, even water, if given proper aeration and proper nutrition, i.e. fertilizer. But this is needlessly expensive and again, potentially problematic for our environment. True top soil is magic. It's ecology is wonderfully complex and is only barely beginning to be understood. No manufactured mix will do what true top soil can do for your garden. Growing plants really needs to be thought of first as growing your soil. True top soil, air, and water are vital to most life forms on Earth. We would all starve without true top soil, unless we were able to subsist on fungi. Labeling requirements for growing mixes are virtually non-existent. Those ingredients that might be listed will be very vague. Notice that no synthetic fertilizers are listed, even if they are there in quantity. Anyone can sell any dirt as topsoil, and people often do as a means to avoid disposal fees for dirt. Get top soil from people removing their raised beds, those who have graded the top few inches of an area, people taking out lawns, etc. or from your own backyard. If there are unused areas of your yard that support a dense mat of weeds, at least during wetter, warmer months, then that is true top soil. Yes there will be weeds, but a good mulch will take care of most of that problem. My advice to any gardener is to start with good top soil, nurture that soil by continually adding organic material, worm castings and compost tea, and use a good mulch. These items are 80-90% of the battle for the vast majority of plants.

What's in the Sta-Green mix? I just went to their website to see, and here are the products they list: Soils & Ammendments African Violet Potting Mix All Purpose Potting Mix Cactus & Succulent Potting Mix Charcoal Flower Planting Mix Houseplant & Tropical Potting Mix Nursery Blend Planting Mix Perlite Seed & Sod Starter Soil Sphagnum Peat Moss Vermiculite First of all, I wouldn't trust a manufacturer which can't spell "amendment." Secondly, I don't see a "Flower and Vegetable Mix."

Look at this as a wonderful opportunity. Less organic material for you to find and labor to add for your plants. If I wanted a lawn with the plantings I know how I would go about it. Three to eight inches isn't very much, so it could be all done by hand ... if we're not talking about a ginormous amount of space. First I would get out as many garden hoses as I have and use them to sketch out the wanted lawn area. Doing it this way gives you a good idea of how it will look in real life, as opposed to a pretty drawing on paper. You can leave them there and reconsider after you've lived with the plan a few days. Move as needed. Once your ready to begin, gather up the mulch that's in the future lawn area and use it to create berms in the flower bed areas, keeping in mind these will decrease in height quite a bit over the next year. But with luck you will still have enough added height to add drama to the floral scene. IF the flowers are to be viewed from both sides , the height needs to be in the center of the beds, with tallest plants in the middle. I did this a couple times with a picket fence at the front of the house and the extra height of those taller plants on the small berm not only helped give more privacy to the front yard and front windows, but the street view was much more eye catching. Everything just looked so much bigger than expected. I'm not talking about a high berm, just enough. ;) Vary the heights of the raised areas too or the whole thing gets too predictable. If by chance you find old dead, thatch where a lawn used to be, and it doesn't seem suitable to be planting on top of , this too can be used for added flower bed height. Just clear a space, throw all that thatch can be used, then cover with more of the compost material. Regular shrubs and perennials can work their way through that sort of thing just fine over the next year or so it takes to break down. I have routinely planted directly in mushroom compost that comes from big trucks ( the bagged is finer) and never had any problems. But that doesn't mean yours isn't slightly different, plus your different climate. What about watering an area and then checking later to see how well it holds moisture ? Heck, throw a test plant in there while your at it and see what happens to it. Hopefully you will not need to spend $$ on more soil to maintain a moisture level. Better to spend on plants and cool hardscaping! Oh, and the perfect birdbath.:) Now get out your collection of garden books and magazines and have fun looking at all the beautiful designs you admired in the past. You have a wonderful, fertile blank slate to work with. How exciting.