We welcome your comments and suggestions on climate change and sustainability solutions for Canberra and region.

 
Current User: Guest
Search Forums:


 






Minimum search word length is 4 characters – Maximum search word length is 84 characters
Wildcard Usage:
*  matches any number of characters    %  matches exactly one character

What's the most environmentally friendly mulch for the garden?

Reply to Post
UserPost

4:37 am
October 6, 2010


marea

Member

posts 446

Four years ago, I got rid of the lawn in my garden and put down about 10cm of mulch. Now it's completely broken down to the point where weeds are coming up everywhere.

What are the most environmentally friendly mulch options and how long can I expect the mulch to last? How deep should the layer of mulch be?

3:46 am
October 7, 2010


Quetzal

Member

posts 60

Hi Marea,

Mulch, I'm topping up my garden now. The last time I mulched in a big way was about 2005.

Depth – I've seen different references to depth, usually 5 to 7cm seems to be the average. Less than this and it can be ineffectual. Equally, however, you don't want to put too much on because it can prevent water from percolating into the soil. Also, heed the warnings that mulch should not be placed all the way up to the trunks of plants.

Types - Here's what I've deduced from my own experience, which has confirmed what is widely written in good gardening books and the internet on the subject.

1. Don't buy the expensive eucy chips, or any chips which are all homogenous in size. The stuff might look good, but it agglomerates, sticks together and prevents water from getting through. Trust me, I made the mistake of buying 15m3 of this stuff and it's taken years to rot down and I've had to go out and break the stuff up manually this spring so I can top up with other stuff. 

2. It's cheaper and it's better to get the 'forest mix' or 'slash'. The latter two are a mixture of different types of bark/wood strips of differing sizes, this means it's less likely to stick together and it will allow water through. If you live south side and want a lot of the stuff, ring up Corkhills and order a truck load. I recommend everyone go have a look at their nearest tip/recycler if they've never done it, it's quite uplifting to see all the green waste people drop off converted into mulch in Canberra. 

3. Mulch doesn't have to last forever. Personally, I'm a huge fan of mulch which degrades within 18 months, but the stuff I favour can't be bought for love or money at the moment. For roses, veggies and fruiting plants people often prefer lucerne or pea straw, because it's high in nitrogen and enriches the soil. Similarly, 'green mulches' are ones you grow yourself and till into the soil. I tried using sugar cane mulch, but I don't think it has the nutritive value of lucerne or pea straw, although it breaks down well enough for veggie garden use. 

4. The type of mulch will have a certain acidity or alkilinity (Ph) that you have to consider based on the type of plants you want to grow. Pine bark, for example, is acidic. Some exotic plants like acidic soil. Native plants often don't. It's worthwhile checking out the Ph of your soil. If your plants are growing well in it, most likely you want a mulch that will have a neutral effect on the Ph. 

5. Wood based mulches can 'denitrify' the soil, that is as they break down they take nitrogen out of the soil. This is a temporary effect. You might want to compensate with a bit of fertiliser, sometimes the pre-packaged mulch has fertiliser in it for this purpose.

6. Expensive is not necessarily best! When I landscaped my nature strip some 6 years ago, I used the cheapest materials and tubestock I could buy. I mulched with layers of newspaper, under wood chip. Under my photinia hedges, I layer mulched using the leaf fall from my street trees, under wood chip. During the drought, I watered with laundry rinse from my washing machine. In both cases, the plants on the verge and the hedge took off in an unexpected way, they grew more luxuriously even than the plants in the garden proper which had been put into imported top soil and mulched with the more expensive eucy chip! So, thin layers of newspaper (2-3 pages max) wetted and laid under some soil or other mulch will break down and can form an excellent mulch. I've just layer mulched with the leaf fall from the oak and plane tree outside again, having checked on the leaf mould formed from the same about 2 years ago. Both are free and work like a dream.

For most gardening issues in Canberra, I rely on "The Canberra Gardener" published by the Horticultural Society of Canberra. I also highly recommend Kevin Walsh's book "Waterwise Gardening", but there are different books on similar materials, including excellent materials for free on the internet. 

8:35 am
October 7, 2010


marea

Member

posts 446

Thanks a lot for that useful advice, Quetzal.

I seem to recall that the last lot of mulch I put down was forest mix/litter as it was all different sizes. Good suggestion about getting the soil Ph tested, and also about the thin layers of newspaper.

6:36 pm
November 25, 2010


marea

Member

posts 446

Last weekend I went out to Corkhill's in Mugga Lane and, as you mentioned in your post, Quetzal, there was a long line of cars with trailers full of green waste waiting to drop it off. It was indeed uplifting to know that it will all be converted into great compost and mulch.

I ordered a pile of the course forest litter and have been spending a few hours most evenings this work laying down this mulch on the garden. I'm still only half way through!!

Following advice from the ACT Government waterwise person who came round a few weeks ago to do a free assessment (a good service for people to use if they haven't done so already), I also created a gravel ditch along the drip line of some thirsty trees that I can use to get water closer to their roots in dry conditions. Hopefully this will dissuade them from sucking dry the adjacent mulched areas where little plants are struggling to compete. One can always hope!

Anyway, a trip out to Mugga Lane is interesting for anyone wanting to know what happens to all your waste and recyclables.

8:23 am
August 25, 2012


Tracey

Guest

marea said:

Four years ago, I got rid of the lawn in my garden and put down about 10cm of mulch. Now it's completely broken down to the point where weeds are coming up everywhere.

What are the most environmentally friendly mulch options and how long can I expect the mulch to last? How deep should the layer of mulch be?

Hi Marea

 

I tend to go for organic options including lucerne mulch (high in calcium), pea straw or sugar cane mulch, leaves from deciduous trees, prunings from the garden. They break down to add nutrients to soil and improve its structure and water-holding abilities. Fallen leaves and prunings from the garden (excluding those affected by fungal disease) are the most environmentally sustainable as you are eliminating travel and you are using recycling product which is already in your back yard. Although these products break down much faster than barks, they are much more beneficial and don't tend to cause nitrogen draw back.

Laugh

8:32 am
August 25, 2012


Tracey

Guest

Post edited 12:55 pm – August 25, 2012 by admin



marea said:

Thanks a lot for that useful advice, Quetzal.

I seem to recall that the last lot of mulch I put down was forest mix/litter as it was all different sizes. Good suggestion about getting the soil Ph tested, and also about the thin layers of newspaper.

Hi Marea

 

Newspaper can be useful as mulch but need to make sure it is black ink only; coloured inke tends to contain nasty chemicals and should be avoidedSmile

1:37 pm
August 25, 2012


marea

Member

posts 446

Thanks a lot for those suggestions Tracey.

I'm starting to see weeds coming through the mulch nearly two years after the last batch, so it is time to consider options again.

Last year, I created a very small no-dig garden and used pea straw on that, as well as organic soil mix. All around it is the mulched area, which now has lots of bits of pine cones (dropped by cockatoos and parrots which fed on them) and pine needles from the neighbouring cypress pines as well as possum droppings (I assume at least one lives in the pine trees).

I gather pine trees really acidify the neighbouring soil, so do you think I should remove the pine needles or just add a mulch that will balance it out? Will pea straw balance out the Ph do you think? Smile

 

10:46 pm
September 4, 2012


Curly

Member

posts 9

Hi Marea

A lot depends on where you are and what you have available.

Pea straw or lucerne hay is a great way to very quickly cover a large area with minimal effort and excellent, quick results both in terms of coverage and soil conditioning. 

But you need to consider greenhouse gas emissions that go into producing and transporting the mulch. 

If you can get a local supplier that is selling recycled mulch or spoilt hay and can deliver large quantities you are doing pretty well. 

Sometimes local farmers have spoilt hay (easiest to find after a lot of rain) but otherwise Corkhill's recycled forest litter and other mulches seems to be the way to go (and it will last a bit longer than hay or straw…if you can cope with or pay for the labour of spreading it.

To work out what you need in cubic meters, measure the area to be covered (meters x meters) then multiply that by 0.1m (for 10cm thick).  By way of a guide, last time I planned on covering my front and back gardens and the narrow beds on either side of my suburban block I calculated it would be 10 cubic meters.  That's a semitrailer load…a lot of shovelling Wink

Re pH, pine needles will acidify the soil…which is great if you are growing berries or azaleas etc.  If not, try adding a little lime or dolomite (separately to any compost).  A pH test kit is an inexpensive investment that will take a lot of guess work out of working with your soil.

 

10:38 am
October 3, 2012


marea

Member

posts 446

Thanks for your suggestions Curly. I'll track down a soil pH test kit. I also like the idea of putting strawberries in the acidic soil.

I used recycled forest litter for mulch last time and I know what you mean about the amount of work involved in shovelling it out!!!

4:07 pm
February 15, 2013


cindy

Member

posts 263

I'd really like to get hold of a one of those shredding machines so that I can mulch up all my wattle bush clippings.

I've looked at LETS http://canlets.org.au/ and Sharehood http://www.thesharehood.org/ but noone seems to have one to loan ..

They are very expensive to buy

 

9:48 am
July 26, 2014


PeterB

Guest

Post edited 9:48 am – July 26, 2014 by PeterB
Post edited 9:49 am – July 26, 2014 by PeterB


 Hi Marea

Newspaper can be useful as mulch but need to make sure it is black ink only; coloured inke tends to contain nasty chemicals and should be avoidedSmile

Not sure where you get that from, Commercial Printers use soy based inks these days. They are organic, environmentally friendly and cheap. Win, win, win!

Most people would be using regular newspapers anyway because they need lots of paper for the job and the color printed stock you are talking about usually has a kaolin (clay) surface on the paper which is not very absorbant.

1:32 pm
August 27, 2014


marea

Member

posts 446

Hi PeterB, it was Tracey who made that comment in response to my reference to use of newspapers, but thanks for your useful clarification.

Reply to Post

Reply to Topic:
What's the most environmentally friendly mulch for the garden?

Guest Name (Required):

Guest Email (Required):

NOTE: New Posts are subject to administrator approval before being displayed

Smileys
Confused Cool Cry Embarassed Frown Kiss Laugh Smile Surprised Wink Yell
Post New Reply

Guest URL (required)

Math Required!
What is the sum of:
3 + 3
   


About the climateXchange Forum

Forum Timezone: Africa/Abidjan

Most Users Ever Online: 34

Currently Online:
2 Guests

Currently Browsing this Topic:
1 Guest

Forum Stats:

Groups: 4
Forums: 15
Topics: 444
Posts: 1109

Membership:

There are 1565 Members
There have been 55 Guests

There is 1 Admin

Top Posters:

marea – 446
cindy – 263
John Symond – 70
Quetzal – 60
OutandAbout – 34
PeterC – 30

Recent New Members: Living Streets Canberra, gender, janesimi01, shirely, kathy, heiha

Administrators: admin (36 Posts)