This past Friday was Arbor Day and I was working with a local community to help celebrate by planting a tree. Of course one of the important parts of planting a tree is making sure to mulch the tree after planting. I've spoken before on the benefits of mulch but with the gardening season really winding up, I figured it was worth it to revisit proper mulching and the benefits it provides.
Proper mulching – save plants, save money. I think like most people we like saving money. I bring this up because I was speaking with someone who had recently seen a lot mulching jobs that were done wrong and used so much mulch it ended up costing money. It could potentially cost more money because of having excessive amounts of mulch surrounding their trees, also known as volcano mulching, compared to what it would cost to properly mulch. The cost is both for all the extra mulch and the potential expense to plant health.
Proper mulching provides numerous benefits to plants, especially trees.
- Moderates soil temperatures
- Helps to maintain moisture
- Overtime breaks down adding organic matter
- Reduces soil compaction
- Reduces soil erosion
- Can help to reduce weeds
- Prevents mechanical damage from mowers and weed whips
To gain all these benefits it's critical that you utilize organic based mulches such as cypress, shredded hardwood, or cedar as examples. I tell people to avoid rock mulch and rubber mulches as they don't provide the benefits listed above. Rock mulch accumulates heat and can't provide the soil temperature moderation that you gain from organic based mulches.
The other part of the equation is making sure to mulch properly. Mulch should be 2-4 inches deep and kept away from the crowns or trunks of plants. Mulch up against plants can cause health issues such as rot by holding moisture against the plant or provide easy access for voles to tree trunks by burrowing through the mulch.
I am often asked how big the mulch ring should be which usually results in an impish grin from me. That is followed by me saying out to the drip line if possible usually followed by shocked looks. At minimum I tell people that you want a 1 to 2 foot mulch circle around the tree for benefit.
Even though over time the organic mulches break down and need to be replaced, the benefits they provide is well worth the investment.