Where in the world you are can be of tremendous assistance to some of us, although my soil is sand while my sisters soil (6 miles west of me) is clay. Usually sand atop a clay base indicates that someone dumped some sand there in an attempt to have a soil kind of easier to cultivate then the clay would be. The clay, under that sand, will keep that sand from draining properly, two different soil types with vastly different drainage capabilities. I would talk with the people at your local office of your state universities Cooperative Extension Service to find out what your soil type shoulld be.

Depends. If the soil has ample amounts of organic matter now and an active Soil Food Web mixing in a high carbon source of material might have little to no adverse affect. However, if the soil lacks adequate amounts of organic matter and an active Soil Food Web, mixing a source of high carbon into the soil can result in the soil bacteria getting busy digesting that carbon and temporarily causing most of the available Nitrogen to be tied up. Once that carbon is digested, or mostly so, that N will be once again available to the plants.

My first garden was created 5 years ago...we took off the sod, amended with compost, tilled and planted and mulched. It was a nightmare. I probably needed 60 times more compost, and never could have afforded it. The following two years I hated working in the garden because it was such hard work with the clay and many plants didn't thrive. I replanted areas many times and each time I would add more compost/mulch, whatever I could get my hands on. I also added a soil conditioner that was very expensive but works like gypsum...breaks down clay. (Who knows, maybe it WAS gypsum with a bigger price tag.) It's 6 years later now and I have to tell you that the garden is just a delight to work in now. I plan to spread gypsum a couple of times each year and continue mulching the beds, but I'm sure I'll never have to do all that double-digging like I did before....just keep on piling on the stuff like everyone wrote above, and before you know it, your beds will be as you need them to be. I also highly recommend that you search out plants that LIKE clay, so that your plantings will be successful. I spent many, many dollars buying plants that needed more drainage than I had and would die...and I wondered why. Some of those plants might do ok for me now in the same garden, but I think it's important to plant things that actually LIKE the ground that they are in today. Good Luck!

Someone here is having good results with amending clay with 50 percent sand and then topping the area with sandy loam. The nurseryman who runs Laguna Hills Nsy and gave the soils class takes the stock he buys and removes most of the mix around the roots. Then he replaces it in peat moss, perlite, pumice,sand and some charcoal. He would add more sand in the mix he sells bagged but the bags would rip or be too expensive to ship. The charcoal is there because the world's best soils have some charcoal content. A building supply in Costa Mesa sells something called Rick's mix that is sandy loam and decomposed granite for improving clay. I have used the best potting mixes I could buy and watch the plants die off in a year. With the mix from Laguna Hills, it doesn't happen. Now I use a mix of my own soil, sand and the Laguna Hills formula. I have been making charcoal all winter and sifting it to throw out the ash which is alkaline. In the old days the nurseries planted in Sandy loam and sold bareroot. No one amended the holes or they planted high in large mounds or raised beds if drainage was poor. Now the wholesalers who planted in real soil are being edged out by those who plant in composted wood. The plants grow fast and are lighter to ship but eventually the breakdown of the planting material kills the plant. You can slow the process by letting the mix dry out almost completely before watering again, but it stresses the plants, especially in our warm climate. In the old days, a nursery could water every day with no root problems at all. A nursery could keep their stock for years and water every day and feed once a month until it sold. Now it's a race to sell the plant before the mix degrades and the roots die. The nurseries have to move their stock quick before then. Even if you plant it in good soil, the plant might not make it to five years because the mix around the trunk has become poisonous to the plant. Some plants grow fast enough to get roots out beyond into good soil. Arborists use augers to drill out holes around the trunk and backfill with sand to get the oxygen into the toxic area. You can also dig into one side and replace with 100 percent soil and six months later do the other side. The formula is stay away from three times the diameter of the trunk when removing roots. That was the formula for moving plants sold in soil wrapped with burlap. Any plant you fix needs to be shaded for two weeks. You can also help them by spraying the leaves with 1 gallon water 1 oz Karo syrup 1 oz seaweed 1 oz fish fertilizer a little wetting agent I hope this helps anyone trying to save a plant. I think it's rotten that plants are being sold that they know will have problems later on. People think it's their fault. The landscape reflects the trend towards only plants that can overcome the crappy potting mix and we all get taught wrongly to add this stuff to the soil at planting time.