How to Calculate Bark Mulch

Posted by Ben Thompson on 03.19.11

It's time to put a refresher coat of bark mulch on your landscape beds.  You make the call to the "mulch man" and he asks, how much mulch (wood chips) do you need?  You freeze and panic.  You ask, how much do most people need?  He says, it depends, but our truck has a minimum order charge of 6 yards to include delivery.  Most people order 6-8 yards.  How many do you want?  You think to yourself...I live in a big house and I have a lot of landscaping....and you say, "I'll take 10 yards please."  After all, you wouldn't want him coming back to bring you 2 yards if you were short and then you'd have to pay for another 6 yards!  You end up only needing 6 yards and there you are with 4 yards of wood chips keeping you from parking in your garage for a month while you try to play it cool with neighbors and invite them to enjoy your benevolence and come get some mulch from you.  Hey, I've done it, you've done it...everyone does it.  I will help you with this right now.

How to Calculate Bark Mulch:

Step 1 - Measure the beds - Length x Width (ft) = Square Footage of a rectangle.  For around trees calculate the area of a circle.  Diameter (ft) / 2 = Radius.  Radius x 3.142 (pi) = SF.  Add all areas up for Total Square Footage

Step 2 - The TRICK! - You need fast volume (cubic feet) at a given depth.  If you take Total Square Footage / 12 = Cubic Feet @ 1" coverage.

Step 3 - Desired Depth.  Take the product of Step 2 x inches = Volume of Mulch in Cubic Feet.  (Tip: To refresh established beds 1.5" - 2" is adequate.)

Step 4a Bags Needed: If you're buying bags at the Home Center they typical are 3 cubic feet per bag.  Result of Step 3 / 3 = number of bags needed.

Step 4b Yards Needed: If buying in bulk yardage take the result of Step 3 / 27 = Cubic Yards required to be delivered.

Dangers of too much Mulch:

  1. Your hands will bleed and your back will hurt from moving too much mulch.
  2. Spend too much money
  3. The never ending pile in your driveway is embarrassing
  4. "Tree volcanos" - too much mulch can kill your trees or promote disease.
  5. Your beds fill up over the years faster than the mulch can decompose they become raised & silly looking.

Enjoy!  If you'd like to order mulch just give me a call.

Topics: On the Radio, bulk mulch, howto