Growing your own mulch

Hi All

Growing my own mulch has long been a goal of mine. We use a lot of mulch in the nursery and garden and at the moment I have no problem sourcing straw but if/when the day comes that the farmers start using their own straw to improve their soil (which is becoming more common practice) I'll be needing to step up my mulch growing efforts. Currently, I grow enough mulch to sustain my perennial beds and around 10 % of my annual beds but rely on imported straw for mulching the other 90% of annual vegetable and nursery beds.

You can view the post with photo's via the link below
http://balkanecologyproject.blogspot.com/2015/03/growing-mulch.html

What makes a good mulch plant ?

My ideal mulch plant grows fast, is drought tolerant, competes minimally with crop plants, does not contain seed that easily spreads, is easy to handle and cut i.e not thorny or prickly or tough and fibrous and can biodegrade relatively quickly.

I've broadly categorized the main sources of mulch we produce in our 1500m2 garden.

Aquatic Plants
I grow emergent wetland species such us Cattails (Typha spp), Sedges (Carex spp. ) and Rushes (Juncus spp.) on the banks of a small pond (6m x 3m), and within a grey water reed bed (1m x 6m). The pond also provides suitable habitat for Hornworts - Ceratophyllum spp. a submerged rootless perennial that gathers on the surface en masse. This plant makes an excellent mulch being rich in nitrogen, growing very fast and is easy to position around the base of plants.
The emergent species provide a good thick carbon rich mulch that helps to reduce evaporation on the terrestrial beds and I cut these back in the spring in case they are used for overwintering invertebrates. Aquatic plants are an excellent source of mulch as there are no issues with seed germinating among your land based crops.


The wildlife pond, aka 'the mulch machine'
Tap rooted Perennial/ Biennials
Deep rooted perennial plants tend to produce a good amount of biomass, are generally drought tolerant and do not compete strongly with our crop plants. I have found native biennial weeds such as Greater Burdock - Arctium lappa a very useful mulch plant with the gigantic leaves growing back very fast after a cut. Lesser Burdock - Arctium minus is also useful albeit to lesser extent Although biennial, if you cut back these plants before flowering you can prolong their life, harvesting good quantities of seed free biomass. I do eventually allow some of the plants to flower and they are much loved by bees among other insects.
Comfrey- Symphytum x uplandicum 'bocking 14' is a classic example of a deep rooted mulch plant. We have the plant scattered throughout the garden and planted in dedicated patches. The plants do require irrigation however and will only provide good leaf yields if grown on fertile soil. Peeing on the plants is recommended
Helianthus tuberosus - Jerusalem Artichoke provide a great source of biomass. For a good tuber harvest its best to wait until the end of the season before harvesting the mulch. We can never consume as much as we produce of these tubers in the kitchen but have found them to be much appreciated by our pigs and an excellent source of fresh winter food for our rabbits.


Leaves of Greater Burdock - Arctium lappa
Nitrogen Fixing Trees and Shrubs
These plants take a while to establish but make an excellent contribution. I've had good results from coppicing Paulownia tomentosa - Empress Tree when they are 3 yrs old and chop and dropping the soft new growth 3 or 4 times a year. I am expecting to also see good results from Alnus incana - Grey Alder and Alnus cordata - Italian Alder. I avoid using thorny Nitrogen Fixing trees and shrubs for this purpose. Annual trimming of shrubs such as Elaeagnus umbellata - Autumn Olive and Cytisus scoparius - Broom alos provides good quantities of mulch.

Click here for more info on nitrogen fixing plants.

Lawn and Ground Cover
One of my favourite sources of mulch is lawn trimmings. They are great for mulching potted plants or applying a mulch into tight spots. Mixed species lawns will contain a more diverse mix of mineral nutrients and lawns including a legume such as Trifolim repens - White Clover can provide a nitrogen rich mulch. Its a good idea to leave some of the trimmings behind to keep the lawn healthy.


Bellis perennis, Trifolium pratense, Taraxadum officinale amongst others in our lawn

Autumn Leaf Fall and Herbaceous Stem Residue.
The annual shedding of leaves from trees and shrubs in our garden make a great contribution to our mulch capital. Leaves can be cleared from paths, lawns and wildflower beds (as they will disrupt the growth in these areas) and concentrated where they are of benefit such as the base of high demanding fruiting shrubs such as Blackcurrants or Blackberries.

Herbaceous perennials such as Mellisa officinalis - Lemon Balm and Mentha spp.- Mints will provide dead stems annually. Its always a good idea to leave hollow stems of some herbaceous perennials to remain for the winter as they are utilized by invertebrates for egg laying and hibernating. If the plant does not have a hollow stem it can be cut back and used for mulch. Foeniculm vulgare - Fennel provides large quantities of biomass and as far as I can tell the stems are not utilised by any organism over the winter.
In the vegetable garden all the remnants of my crops after harvesting go straight back to the surface for recycling.


Foeniculum vulgare and other herbaceous perennials
Tree Prunings
Woody prunings from shrubs, trees and vines cut into small pieces (5-10cm) make good mulch in the mature areas of the forest garden with well established fungal soils specialising in breaking down the lignified woody material.


Scaling up Mulch Production
In order to grow enough mulch to provide a water retaining, weed excluding barrier for my annual and nursery beds I would certainly need more space. A larger wetland area would be ideal, with aquatic species growing very fast and the seed bearing parts of the plants being non problematic to use on terrestrial beds. If you don't have a reliable aquatic habitat the next best option for growing quantities of mulch without irrigation and fertilisation is probably grass.

During my next post I'll be sharing a plan where using the lessons garnered from small scale systems, we'll be growing mulch to support approx 670 fruit trees and 1360 soft fruit shrubs on a 5ha Agroforestry Project (design layout below).

Cheers,

www.balkep.org
http://balkanecologyproject.blogspot.com/

Although my Melissa is a voracious grower I have not thought of it for mulch, since I harvest it, and what's left usually has seeds all through it. But I could see the potential.

Currently my best and easiest mulch producers are pecan, catalpa, and hackberry trees. I have them set on automatic since my garden is just near the drip lines, free mulch covers the beds. From other areas on my property I will rake up huge piles of leaves and then stick them in where the chickens sleep. After a month or so the leaves are shredded and covered in nutrients so I move the coop and spread the fresh mulch onto specific areas that need it.

I have not planted it yet, but arundo donax Is in my area and looks to be choice for many applications. It has the stigma of destroying riparian habitats once it is cut loose into nature, but if you do not live in a hurricane area it does not spread with seeds Very easily. Once established it is difficult to remove. Many people in this area completely ignore it and it is seen on roadsides and in drainage ditches, but certain people I have noticed using it for privacy hedges and chop and drop every winter. This chopping appears to keep it from spreading much at all and it will just repeat similar growth year after year.

What about clumping grasses like pampas ? They seem to produce a lot of long leaves and will also be just fine getting a hair cut each year.

Paul Alfrey wrote:

My ideal mulch plant grows fast, is drought tolerant, competes minimally with crop plants, does not contain seed that easily spreads, is easy to handle and cut i.e not thorny or prickly or tough and fibrous and can biodegrade relatively quickly.

Do you really want mulch plants to break down quickly? My ideal mulch would be one the breaks down, but breaks down fairly slowly so doesn't need such frequent applications. Better yet is a living mulch that doesn't need any care - still experimenting in our patch but comfrey seems to fit that bill in many applications, successfully suppressing grass and letting perennials thrive.

To grow your own mulch, I would plan a cover crop over the dead season ( for me that is winter, if you live in the tropics it might be the dry hot summer). I would then crimp but not cut/mow the plant at the end of the season. This will ensure that it doesn't set seed and reseed it self or even regrow to compete with your annuals. Or maybe you can set aside 10% of you land and use it to grow cover crop year round and then apply it to the rest of the farm. Hybrid willow/poplar can grow as much as 12ft per year.

A system that needs regular tending becomes a job that needs doing... mulching small areas of intensively managed annual beds makes sense, as can deep woodchip in orchards that only needs sporadic topping up (I get mine when ever a tree surgeon is working nearby). Growing willows specifically to chop and shred for mulch sounds like a lot of work.

Again, I'll cry out for the benefits of living mulches that can coexist with your edible plants...

Great suggestions thank you all.

Micheal your point on living mulches has prompted me to add section to the post including the living mulches i have observed working best in my garden i.e. Ajuga reptans - Bugle, Lamium maculatum - Spotted Dead Nettle, Sedem spurium - Caucasian Stonecrop and Stachys officinalis - Betony. Although not suitable in many situations living mulches (ground cover) are certainly preferable in mature area's of the forest garden where plants have established good foraging root systems.

Zach clumping grasses such as Pampus are great for producing biomass but are very unpleasant to handle and difficult to cut back once established. I have never tried cutting back a young plant so cannot vouch for how difficult it may be and how fast it recovers.

Regarding quick decomposition. If you have high nutrient demanding crops (as is often the case in my garden) you want your mulch to biodegrade relatively quickly in order to feed the soil microbiota which will release the nutrients from the mulch making them available to the plants.

Cheers,

Paul

I'm growing Miscanthus Giganteus (sterile, won't set to seed), Helianthus spp., Pampa grass and Arundo donax to make some mulch.
Would have loved to grow Alfafa, but didn't find the time to do so yet.
All this is quite useless until I find a chaff cutter...