Many plants such as evergreens and blueberries prefer a more acidic soil with a pH of between 6 and 6.5 and you can use a soil test from the garden center to check the acidity or pH of your soil. To increase acidity (which means lowering the pH) add  peat moss, pine needles or lots of compost.  Highly organic soil is more acid. You can also apply elemental sulfur to lower the pH and make the soil more acid or iron sulfate that works in three to four weeks to make the soil more acid. The amounts to use should be listed on the package, and these products are available at nurseries and garden centers. Keep growing, Marianne Binetti