Ramial Wood Chips is a good choice verses Pine Park mulch is a bad choice
Why isn’t Pine Bark mulch good for my plants? When pine bark mulch starts to break down some not so good chemicals such as terpenes and phenols are released into the soil that damage biological activity. Some of these compounds are antimicrobial. These compounds, and or chemicals, are good while on the tree as bark to protect itself from the environment, pathogens and pests. But not in large quantities in the soil.
Pine bark mulch is used almost extensively in landscape bed preparation but should not be 100%. Pine bark mulch when fine and medium-sized is a bad choice when it comes to improving soil biology and fertility. Several years in a row of Pine bark mulch applications can not only damage beneficial organisms in the soil but also develop into a compaction zone reducing air and water flow into the plants root system. In some cases we’ve seen this layer of pine bark mulch become hydrophobic https://en.wikipedia.org/wiki/Hydrophobic_effect
A much better choice would be Ramial Wood chip mulch (ground up tree tops and shrub trimmings). Ramial Wood chips are a perfect balance of carbon and nitrogen (30:1) from the wood, bark, flowers, fruit, buds, stems, cambium, xylem, phloem and green leaves. The branches and or twigs can be less than 2 ½ inches around the large end of the branch. Species that have been chipped should mostly be deciduous for the benefit of soluble lignin used by the white fungi rots. A diversity of mixed species chipped, containing no more than 20% softwood (conifers like pines, spruce, fir, cedar, etc.), will not only favor the beneficial white rot fungi but will allow you to spread the wood chips fresh. The wide diversity of microbial foods in Ramial wood chip mulch will increase the diversity of bacteria and fungi that helps hold these mulches onto steep slopes much better than pine bark mulch.
Here is a great Primer by Michael Phillips on Ramial Wood Chips: http://www.groworganicapples.com/organic-orcharding-articles/ramial-wood-chip-primer.php
Harrington’s OLC making enhanced Ramial Wood Mulch:
Call for pricing on Ramial Wood Mulch http://harringtonsorganic.com/residential-products/#lightbox/1