mulch depth

19 years ago

hello , have placed mulch around 12 mature red cedar trees(30 ft tall)-hardwood chips 12" deep X 12"from tree trunk all the way around(threfore about 2'8" across)----have flattened the tops of the mulch as it goes around the trees. I did this to more or less protect the roots from indiscriminate spraying of roundup by idiot sibling around the base of any trees or shrubs showing grass or weeds that mower cannot get to and have to be weekwhacked-(lazy and an idiot!)

---So my question is regarding the correct mulch application

i noticed the mulch retains alot of moisture even after 7 days of no rain--1.)is 12" too deep? And, 2.) should the flattened tops be shaped up conically around tree trunk to create a more water shedding kind of form?

thanks, mike

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Comments (5)

gardengal48 (PNW Z8/9)
19 years ago
12" is waaayy too thick! Mulch around trees or shrubs should be only 2-4" thick and ideally spread out to the drip line. Keep it at least 6" away from the trunk or any woody portions of shrubs. No mounding is necessary.
quirkyquercus
19 years ago
12" is what you call a mulch volcano :-)
Scrape it down to 2-4" and save the rest for use later on.
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lou_spicewood_tx
19 years ago
Yep what other says and keep root flares exposed.
glenn_sun
Original Author
19 years ago
well, i guess that makes two idiots in this family--:)-but i didnt get the lazy gene so i will go out and place the mulch properly-will spread it out from tree to tree and away from the trunks , useing it as a carpet along the tree "lane" to deweed the areas under the trees---
----another question
---will OK to use weed barrier under the mulch to keep out the weeks under these trees? its alot of weed barrier, but my brother uses alot of weed killer--im usually not around, so i have no control over it-i could beat him up, but you cant beat genetics out of a person, if they were born lazy, thats the way its always going to be! (not using smily face, its not funny-very frustrating though)
ken_adrian Adrian MI cold Z5
19 years ago
forget the barrier... waste of money donated to snake oil type sales people ...

one minute after it is placed down .. wind borne weed seeds will start accumulating on top if it and the mulch and in a few years time... it will be useless ...

most weed killers should have no effect on tree bark .... though careful application would be appreciated ...

your sibling comments are a hoot ... lol .. beat the genes out of him ...

i use roundup on mulch circles all the time ... no tree loss .. it has to be sprayed on the entire GREEN canopy to impact the tree ... once it hits the soil it is basically useless ... though i suppose if you dump a 50 gal barrel around the tree.. it will probably kill it ...

also .. i make 3 to 4 foot circles around the trees ... dictated by the radius of my riding mower .... use a yard stick .. and some landscape paint [sprays upside down] ... make a circle... roundup the grass/weeds ...a week or two later respray to ensure full kill .. then add 2 to 4 inches of mulch... leaving a 6 inch naked band at the edge of the circle.. to avoid the necessity of weedwhipping mulch ... those missiles hurt .... respray the band when needed ...

the depth is a function of the mulch itself .. you want 2 to 3 inches.. after it settles.. small mulch particles settle different than large ones ... so you need to observe how it settles by the end of the year ... and act appropriately to maintain about 3 inches .... with about one inch at the trunk .. and if rodents are a problem .. none at the trunk to keep them away during winter ...

good luck

ken