On this week’s episode, the guys talk about soil chemistry and the importance of having the correct soil pH. They define pH as the concentration of free hydrogen ions and explain how the pH scale works. Most vegetable annuals prefer a soil pH that is just slightly acidic, usually around 6.5. They talk about factors that can lower soil pH, which include rainfall, addition of fertilizer and certain cover crops. Greg talks about the importance of performing periodic soil tests to keep an eye on the soil chemistry. While soil pH can be easily raised with the addition of lime, it is extremely impossible to lower pH if you get it too high. That’s why it’s important to have a soil test so that the correct amounts of any pH adjusting material are added. Finally, they discuss the important of macronutrients like nitrogen, phosphorous, potassium, calcium and sulfur. If pH is incorrect, then the availability of these nutrients will be affected.
On the Show & Tell segment this week, Travis talks about his recent sweet potato harvest and brings an extremely large sweet potato to show the audience. He mentions several techniques he tried this year that seemed to work well on his sweet potatoes. They also talk about the Rattlesnake pole beans growing in Travis’ garden. These have been a very prolific crop thus far and are very appealing to the eye because of their purple color.
On the Q&A segment, they answer a question about composting and whether it should be applied to the entire garden or just where the plants are going to be. Travis mentions that compost can serve two purposes — to improve the workability of the soil and also to provide nutrients. He also mentions that most composts are carbon-based, while they use mostly manure-based compost which has much more nitrogen. The carbon-based composts may be applied to the entire garden area as a way to amend or improve the soil structure, while the manure-based composts are typically only applied along the row due to the high nitrogen content.