Manure is a critical ingredient in your soil health – both animal manures and ‘green’ (plant-based’) manures. I use both – but it can be confusing to know which kind of poo to use in your garden.
Green (Plant-based) Manures
Green manures are nitrogen-fixing plants that feed the soil from the nitrogen nodules on their roots. There are many different green manures – you can buy them easily from most nurseries and online. This season I planted a few mixes and a single species variety (fenugreek). Plant in a bed where you have had a heavy feeding crop like tomatoes – just bear in mind you will need to leave that plot aside for about 10 weeks. You won’t need to do much to it in that time while the green manures grows.
The trick with green manures is to cut them off at the base before they set seeds – either just before or just as they flower.
Once you have chopped them down, leave them alone to sit on top of your bed for another week or so. Don’t dig over the bed.
A week later, come back and dig the plants into your bed. Don’t be tempted to dig out the plants. This is when the magic happens! The nitrogen nodules will release their precious nitrogen into your soil at this point.
Come back a week later and dig it over again. Then let the plants continue to rot down. They will build structure into your soil.
You should do this in late Winter or early Spring, at least a month before planting Spring or Summer veggies. My soil here doesn’t warm up enough for Summer veggies until mid-late October, giving these plants plenty of time to rot down. I’m going to follow up these beds with a sprinkling of rock dust minerals and a bag of sheep manure and compost from my bins for extra nutrition and organic matter.
Animal Manure
Animal manures are useful in the organic garden. Vegans choose not to use these, as do some vegetarians. While I sympathise with these viewpoints, as a vegetarian I personally do choose to use these poos. Animal manures are a waste product and are a valuable soil amendment and compost activator. Aged and well-composted, they are safe to use in home gardens, including in soils used to grow vegetables and fruit.
Moreover, if we do not use animal manures to improve and amend our soils, where will the poo go? Landfill! Once there, manure will either break down anaerobically and create harmful greenhouse gases, or leach into waterways. In my opinion, not using manures is wasteful and harmful for the environment.
Some manures are better for the home garden than others. Different poos have different uses, and there are some I prefer to avoid (although some people do).
Compost Activators
I use some manures to activate compost. Compost is made up of ‘greens’ (grass clippings, kitchen waste, coffee grounds, and garden cuttings and weeds) and ‘browns’ (cardboard and paper, straw, dried leaves). A good blend of browns and greens is needed to make good compost – too many greens, and the compost will become anaerobic and smelly. Too many browns, and it will be too dry and will not compost quickly enough. To help your compost get moving and heat up, it helps to add some fresh manure.
I believe that the best manures to activate home compost are chicken, pigeon, rabbit, donkey, and horse.
Pigeon
Pigeon manure is the king of manure, in my opinion, but it is hard to get. My neighbour used to race pigeons and still has a coop. Every now and then, I find a bag of pungent pigeon poo at the bottom of our steps. No, he’s not sending me a message to get out of town – he’s giving me a bag of poop because he actually likes me, I promise.
Pigeon poo is very rich in nitrogen and must be composted for several months before it is ready to be used, or it will burn any plant it touches. Half a shopping bag in each compost bin sets the microbes to work like nothing else. Turn the compost once a month and in a few months it will be gorgeous.
Chicken
I also have ready access to fresh chicken manure mixed with straw from our coop, providing a mix of poo and browns in the compost bins every couple of weeks. Chicken manure is also very high in nitrogen, but not strong as pigeon. Every couple of weeks, I take a couple of inches of muck and crud off the top of their run, and dump that in the compost as well. That is also basically half-rotted chook poo and plants, and activates the compost almost as well as the pigeon poo.
Rabbit and Donkey
Very occasionally I receive a bag of rabbit poo from my brother-in-law. Rabbit poo is not high in nutrients but is light and dry and provides structure to the compost. Donkey poo is quite similar. You’d think it would be similar to horse manure, but actually it is quite dry and light, and provides both nutrients and structure to the compost. Due to the high likelihood of weed transference, it must be composted for at least six months.
Horse
Lastly, I occasionally add a couple of bags of horse manure to the compost bin. However, generally it is my preference not to use it. Horse manure can carry a lot of weed seeds. While their manure has value from a nutrient perspective and it adds good structure to the soil, it can bring weeds to the garden and must be composted for quite a while before use. I can get horse manure easily for free from the nearby race track, but for the most part choose not to because I have access to other manures. If I did not, I would use the horse manure, but would have to compost for longer than other manures.
Manures for use as a soil amendment
The only time I add manures directly to the garden without composting are already aged cow or sheep manure, which I buy from a trusted supplier, or pelletised chicken manure (for example, Dynamic Lifter). I never add manure that has not been well aged or composted directly to the garden. This is because fresh manure can cause several problems:
- It can carry diseases that can transfer to the soil and the plants;
- It can contain ungerminated weed seeds that can infest your garden;
- If it is very high in nitrogen, it can burn plants.
My preferred aged manure is well-aged sheep manure, used as an amendment around fruit trees in Winter. Sheep manure is gentle, high in potassium but lower in nitrogen, adding structure to the soil without the risk of burning plants. There is a risk of some weed seeds transferring, but I have not had this issue.
Cow manure is also acceptable. Like sheep, they have four stomachs, which means their food is pretty well-digested by the time their manure is produced. As such, most weed seeds have been digested or killed off by the time they come out.
Dynamic Lifter or similar pelletised chicken manure products are commercially produced organic fertilisers, safe to use on the garden and high in nutrients. I use these directly on the garden at the start and end of each planting season to replenish the soil and feed the plants. While it is high in nitrogen, it will not burn plants due to its slow release, pelletised form. I use a similar organic chicken manure-based product to feed my fruit trees during Spring and Summer.
Poos to avoid
There are some manures I avoid. I believe that pig manure is a risk to the home garden, as it can harbour more disease than other manures. The home compost bin does not reach a high enough temperature to destroy these. Also it stinks like hell, which is a risk to neighbourly relations. I could end up with a less friendly bag of poo on my doorstep if I started using pig manure.
Cat and dog poo are not safe to use on the home garden, although there are composting units available specifically for dog and cat waste, these are to break it down so you don’t contaminate landfill, not to use it on your vegetable garden. Cat poo can carry diseases such as toxoplasmosis and should not be used in any garden where produce is grown for consumption.
It should go without saying, but human waste should also not be used on the home garden. Composting toilets have been in existence for many years, but most homes do not have these specialist facilities.