Sunday, May 27, 2012
My apologies. I have been AWOL for some time now. At the end of April my father died after a long illness. As his oldest son and de facto guardian in recent years, it fell to me to organize his departure, and I was absent for almost 10 days. Many joined together to celebrate his life. Now it is time to return to ours.
I left in the middle of talking about soil amendments and the importance of adding organic matter to the soil. Today I want to focus on PH. In addition to being heavy clay, our local soil is also naturally alkaline. For the prairie plants native to this area, this is no problem. For many others, however, including many ordinary vegetables, a less alkaline soil would be welcome.
For many evergreens and for plants that like shade, alkaline soil is inhospitable. They are used to a shady spot in a forest rich in organic matter - especially the acidic droppings of pines and other trees.
This means that we gardeners should skew our soil amendments toward the acid side. We want our vegetable gardens to have a neutral PH -- about 7.0. If we are planting hollies, rhododendron, or many hydrangea, we want our soil on the acid side of neutral. If you have evergreens or hydrangea whose leaves seem to be abnormally yellow, that is an indication of chlorosis -- an affliction caused by soil that is too alkaline.
In the city our naturally alkaline soil is accentuated by things like tuck pointing that add yet more lime to the soil and thus increase the alkalinity.
For those who have established beds, you should use whatever is available to increase the acidity of your soil. The simplest of these is to throw your coffee grounds into your plant beds. A simple crock in the kitchen can store up several days worth of coffee grounds until you have the energy to take them outside.
For problem areas, or for new beds you should include, in addition to compost, lots of peat moss ( which is acidic) and a teaspoon of soil sulfur for each plant. The sulfur should be mixed into the area below the plant. You do not want to let the plant roots be burned by direct contact with the sulfur.
The Beverly area in Chicago is particularly shady. For those of us who live there, these recommendations are especially relevent. If you are going to plant a new bed, you have a wonderful opportunity to provide an environment that your plants will love for years. If you already have established beds, bit by bit amendments will also help. Scatch in a bit of soil sulfur around your hollies or hydrangeas every spring. Use some peat moss a a mulch, and make use of your coffee grounds.