A very common myth associated to spruce and other evergreen species such as fir and pine is that they acidify and lower soil pH. There are many remedies for raising soil pH due to the presence of evergreens, do not use these products as they may cause more harm than good to your soil.
Research has proven that evergreens do not have an immediate effect on soil pH but over centuries and millennia they may. Another factor in dispelling the myth is that our soils in the Calgary and area have a high buffering capacity. Buffering capacity is the ability to resist a change in pH, meaning if you try to lower or raise soil pH the soil will return to it’s original pH quickly.
Our soil, and water for that matter, are alkaline and have a high calcium content. Calcium is what gives our soil and water a strong resistance to pH change. The myth came about because, grass and many other plants do not grow under or near a spruce. Competition for light and water is the reason why plants don’t grow well or die under evergreens.
Bergenia is a broad leaf creeping perennial plant that grows well in a dry shady area if you are looking for a suggestion for planting. You can raise the tree canopy to allow for more light at a sacrifice for tree balance, health, value and appearance. Every live limb removed from a tree is an injury, removing live growth from a tree should be done with reason and purpose. What do you value more your grass or your tree? Rather than fight a losing battle with a tree, work with it. Adding mulch under and extending the bed or dead ring around the tree is a great solution. A mulch bed makes a natural healthy environment for the roots and a nice edge that is more maintenance free. If you are adding mulch make sure that it is around 2”-4” deep while making sure not to put any around or bury the tree trunk.
