I generally recommend choosing trees, shrubs and perennials that fit the conditions a site has to offer, rather than attempting to "improve" the soil to fit the plants you'd like to grow.
However, when it comes to vegetable and annual flower gardens, its impossible to add too much organic matter!
The links below will take you to "Garden Journeys" episodes where I'll show you how to determine the texture of the soils on your property, as well as options for increasing their organic matter content.
If the links above don't work, click the "back" button on your browser to return to this page. Then, if you would, click on the link below to send me an e-mail to let me know that the link now leads to a page that's no longer valid. I'll then do my best to track down the new address for the page and/or point you toward a different resource.
Terry L. Ettinger Horticulture Consulting Services takes no direct or implied responsibility for the information or recommendations found at any other website. Please keep in mind that all do-it-yourself activities involve a degree of risk. Skills, materials, tools, and site conditions vary widely. The reader remains responsible for the selection and use of tools, materials, and methods. Always obey local codes and laws, follow manufacturers’ operating instructions, and observe safety precautions at all times. Please read all labels carefully before purchasing, applying and storing any pesticide.