Mulch 18.1.2011


Anyone who gardens knows there are good reasons to mulch around plants.

Mulching around trees does more than just reduce water loss from the ground.. Since mulch usually makes its irritating way into your shoes it tends to put you off walking under the tree, reducing soil compaction.

It also inhibits weed and grass growth, meaning mowing isn’t needed around the trees – so there’s no damage to the trunk from the mower. Our council does a great job mulching many of our mature parkland trees. Take a walk through Civic Park or a drive past the Norfolk Island pines in Hamilton and Bar Beach. It’s a credit to the tree team.

Grass clippings, on the other hand, don’t make a great mulch for trees and are not an example of something our council would use around veteran trees. If you’re going to put grass clippings around a tree, they shouldn’t be piled up against the trunk of the tree. Please correct me if I’m wrong – just leave a comment. Here (19KB) is an information sheet written by Wellington Council asking residents not to do this.  

There is a beautiful row of Hill’s figs in Broadmeadow and it saddens me every time I drive past to see piles of grass clippings around almost half the trees.

Stood and watched the flying foxes arrive in the inner city last night then realised we were completely ringed by their calls. The figs must be ripe.

Took the dog for a walk after dark tonight and the noise of the bats was amazing. It’s fantastic that Council has been planting new figs for some years, and it would be great to see even more. A friend told me about a resident in Enmore who was trying to save the last Hill’s fig in his suburb. Impossible to imagine.



Tags: , , , , , , , , , , , ,

One Response to “Mulch 18.1.2011”

  1. Sean Freeman Says:

    I totally agree Caity, mulch can be one of the best and simplest improvements we can make to a tree’s growing environment.

    Perhaps one of the biggests positives it can produce is the provision of carbon to the soil organisms, it is afterall the fuel that drives the soil ecosystem…yes it is really the sun which through photosynthesis has formed the wood tissues from which the carbon is gradually obtained during decomposition.

    If possible mature (partially composted) woodchip is preferrable to green woodchip (fresh from the chipper). Not so much because of the oft mentioned nitrogen drawdown (an effect which is relatively minor) but rather because of the heat generated during the initial microbial activity on the wood tissues….just think how hot your compost heap can get, well only a few soil orgnisms can thrive in elevated temperatures many will be driven off and some killed.

    A thick layer of green mulch can temporarily cook the upper portion of the soil – not desirable.

    The older your tree is the more sensitive it becomes to sudden dramatic changes so well composted mulch is best, and if at all possible mulch that is comprised of wood chip and clippings from the plants that would be expected to grow in association with your tree (this of course includes chip from the tree itself or trees of the same species).

    None of this is to suggest that you can’t see trees growing without obvious mulch layers they can and do…..BUT even trees that grow naturally in open woodland with native grasses and forbs do have a mulch layer…sometimes suprisingly thick…it is just that often it is hidden by the understorey and ground layer plants.

    Our long suffering urban street trees very often are forced into very hostile environments devoid of almost any organic matter outside of the soil in their pots/bags before they are put into holes in the ground. The fact that any of them survive for any length of time under such adverse conditions is testiment tot he incredible resiliance of this extraordinarly long lived organisms.

    Mulch is an essenial element in the soil food web…which in turn is absolutely critical to the health of all plants, trees included.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: