Hello Professor Lee,
I want to grow a plant outside next to my house. The side I want to grow on is very secure and gets lots of light. The soil is however lousy. It’s mostly just red clay and rocks. How should I prepare the soil to get the best results?
I suggest starting some seedlings in starter containers. When they are ready prepare the planting bed by digging out about 18 to 20 inches of soil. Save the soil on a tarp or a wheelbarrow for later use. Next use a shovel to loosen the soil at the bottom of the hole. This will aid in water drainage. Add a couple inches of rock or gravel to further aid in drainage.
Next put down a 3 to 4 inch layer of well composted cow, chicken, or mushroom compost to act as a natural fertilizer. Second fill the remainder of the hole with a mixture of compost, perlite, and vermiculite. Now water the soil mix to help settle things and prevent any dry spots.
This next part might seem a little weird, but it really does work. Lay down a layer of wet cardboard and punch a planting hole every place you want to start a plant. This is why having seedlings already started and ready to transplant makes everything a whole lot easier. Cover the rest of the exposed cardboard with 3 to 4 inches of mulch right up to the stems of the plants. Use the clay you dug out of the planting bed to build a wall around the bed at least six inches high. Compact the clay as you build the wall to make it as solid as possible. This will catch rain and make watering a lot easier.
This is about as cut and dry as I can explain to build a trouble free planting bed. I hope it helps