Calculating the Amount of Mulch Required.


The trunk measures 24 inches average on the tree. How much mulch would you estimate could top that oval shaped drip line, if I just dropped 26 kg of compost? I’d do the math, but my covid-fogged brain, and the back stretch aren’t helping me do much these days. The good news is the local acupuncturist is making a living. It’s amazing how the tree sucks in the compost from last year!


Hello again:  I do not have enough information to calculate the amount of mulch you require. Weight and volume measurements between the compost you used and the mulch you chose will be different.  ie 26 kg of compost will have a different volume than 26 kg of the mulch. Volume is the important measure to determine.  Most bags of compost or mulch will have both weight and volume measures.

Here is a guide to do help you determine how much you may need: mulch .   It is an American article so you need to measure the area around the tree in inches or feet.  Do not worry about the mulching area being an ovoid, rather just treat the entire area like a circle. Choose the widest diameter.  In any case buy a bag or two more than your calculations suggest as you will be able to use it next year or on other parts of your or your neighbour’s garden. And remember to add only 2-3 in of depth and leave a few inches bare between the bark and the beginning of mulching.  Best wishes.