Mulcing 102 - Types of mulch

Mulching does many things including,

• Protects soil from extremes in temperature and moisture,
• Inhibits the growth of weeds
• Protects the trunks of trees from injury
  
• Can add organic matter to the soils

Lots of different materials qualify as mulch, from rocks to recycled rubber, but the most effective mulch in the urban landscape is arborist wood chips. Why?

Coarse woody debris, or wood chips, break down slowly and release their stored energy back into the ground for use by other plants. Interestingly, their slow release rate is less likely to overstimulate plants in the way that a commercial fertilizer or compost would do.

Wood chips also require a fungal relationship to break down. This fungal symbiosis then reacts with roots of plants in a form called mychorizae (see image above), which is neither root or fungus, but a whole new organism benefiting both. Fungal growth also inhabits the niche that weeds like to grow in.

In other words, more fungal activity in soils equals less weeds!

The Douglas-fir tree, a NW favorite

I am often asked, "What is your favorite tree?"

My favorite tree is the Douglas-fir, Pseudotsuga menziesii.

Like many of us in the Pacific NW, this tree is not easily put into a box. Sometimes called a pioneer species, it may live to well over a thousand years. Often dismissed as too big, the Douglas-fir is a very strong, flexible tree, capable of adapting to the urban environment.

The serious question for arborists in the NW is how do we care for a tree that can grow to 150 feet or more, right next to a house? Many of my fellow arborists have been debating this for years now. If you have one of these amazing trees, stop and admire it from time to time.