A Guide To Better Gardening
With Compost
It has no rival as a soil amendment, able to favorably alter the ground’s physical properties and nutritional content.
As mulch, it does what other inorganic mulching materials do – plus more (more about this later).
And it is the greenest thing you can do!
You’ve heard and read about compost before, and why gardeners call it “black gold.” And if you want to learn how to create “black gold” yourself and improve your garden, you’re in the right place.
This guide from GrabCo will show you:
Want to start composting? It’s easy! A compost bin – and the commitment to put your organic waste into it – is all you need to get started. And as you’ll see later on, this tiny initial investment gives you a lot of value for money.
If you are a gardener, having a compost pile can greatly reduce what you spend on fertiliser and yard waste removal and maintenance.
And if you really get into the habit of putting organic waste into the compost bin, the amount of waste that goes into your other bins get reduced eventually – and so are your expenses for waste removal!
Now, don’t think that affordability and savings are all you get from composting. Read on and discover how composting can keep your garden and surroundings happier and healthier.
Where does your waste go? If you answered landfills, read on and pay attention!
Landfills have drastically decreased the negative impacts they once had on the environment. In the past, the product of anaerobic decomposition – methane – was released into the air by landfill sites, making a huge contribution to global warming.
However, in recent years, more modern landfills have been designed to utilise this greenhouse gas for better, rather than worse.
Modern landfills are now designed to maximise biodegradation in their anaerobic environment to produce as much methane as possible. The methane is then collected and converted into clean energy that can then be put back onto the grid or even used as fuel for vehicles.
Landfill gas-to-energy is one of the cheapest green energies available; costing less than solar, hydro, and wind!
Although landfills have improved and are now actively working towards a healthier planet, there are still negatives to landfill use for waste.
The trucks used for transporting waste to landfill sites emit harmful carbon dioxide, another greenhouse gas that contributes to global warming – this cannot be collected and converted.
Also, although the methane problem seems to have been resolved within landfill sites, we still have to consider water pollution, potential leaks within the gas converters and other toxic waste variables.
Therefore, it’s always good to try and stick to the familiar phrase, “Reuse, Reduce, Recycle.”
You want to minimise the amount of waste that goes into landfills as much as possible – and reduce your environmental impact as well.
Composting is a convenient way to achieve that. With composting, the organic waste you produce is decomposed properly and naturally – free from the potential landfill site problems.
Composting is one of the best things you can do for your soil and garden – and for numerous reasons!
To start, compost is packed with a full spectrum of essential nutrients, even including macro and micronutrients often not found in synthetic commercial fertilisers! And unlike synthetic fertilisers, compost slowly releases the nutrients spanning months or even years, ensuring the plants get all of its nutritious contents.
If you want to grow a bountiful harvest of vegetables in your garden, keeping an eye on your soil’s pH is a top priority. It’s a measurement of its degree of acidity or alkalinity, and it plays a big role in the availability of essential plant nutrients.
You want a neutral soil – one with a pH of 7.
Soils with a pH lower than 7 are considered acidic, and such soils are associated with a host of toxicities, nutrient deficiencies, and other conditions that restrict plant growth.
Garden soils with a pH higher than 7, on the other hand, are alkaline. These soils often have poor structure, and their low infiltration capacity make them a terrible choice for agriculture and gardening.
If your garden soil suffers from a pH imbalance, the addition of compost can act as a buffer and bring the pH levels to the ideal range.
Compost also improves the soil structure by binding particles into aggregates that have tiny spaces able to hold moisture, nutrients, and air. And this is beneficial whatever type of soil you have.
For example, let’s say you have a sandy garden soil. Sandy soils have a loose structure and coarse particles, a poor recipe for holding water and nutrients for plants.
Adding compost to sandy soil binds the coarse and loose particles together, improving the ground’s ability to retain moisture and nutrients while allowing plant roots to penetrate easily for nourishment.
Clay soils, on the other hand, are heavy and dense. The particles are small and tightly knit together, able to hold water moisture unlike sandy soils.
The problem with clay soil’s dense structure is it’s prone to water-logging. A water-logged clay soil is unable to drain water, preventing plants from getting enough air which can lead to yellow leaves and root rot.
When compost is mixed with dense clay soil, the former binds the clay particles to form larger particles that have enough spaces between them. These newly formed spaces results to better drainage and aeration while reducing the risk of potential water-logging.
First things first: adding compost to the soil won’t get rid of any existing plant disease and pests.
However, a compost-treated soil has been shown to produce healthier plants with fewer pest problems and diseases. Adding compost to the soil keeps diseases and harmful insects that can run wild in sterile soil in check.
Leaf-based compost, in particular, shows great promise in suppressing microscopic and parasitic worms called nematodes.
Moreover, the useful critters that reside in the soil do a great job of breaking down organic compounds including manure, pesticides, and plant residue, preventing the compounds from reaching bodies of water and causing pollution.
When Beth Chatto set out to create her world-famous gravel garden in 1992, the first thing she did was add all-natural compost to the soil.
True, the British plantswoman’s choice of drought-tolerant plants and the addition of gravel mulch greatly contributed to the garden’s success. But the role played by compost in creating the gravel garden cannot be ignored.
Compost in a thin layer acts as a barrier when added to bare soil, preventing the water in the ground from evaporating and keeping the soil moist. It also reduces the need for watering by increasing the soil’s moisture retention properties. As a matter of fact, a 5% increase in organic material boosts the soil’s water retention capacity by up to 4 times.
The microorganisms and friendly creepy crawlers break down the organic matter in compost, releasing a glue-like substance in the process. The sticky substance fuses soil particles together, forming flaky and irregularly-shaped aggregates. The crumbly aggregates have spaces between them, allowing air to penetrate while retaining water.
A study back in 2000 reported by Michigan State University found that a compost-amended, 8-inch plow layer can hold 1.9 inches of water, while the same amount of unamended soil can only retain 1.3 inches of water. For vegetables which require an inch of water every week, adding compost meant a 2-week supply of water!
Compost isn’t new. Even our ancestors knew that compost is an awesome addition to the soil and a key ingredient for a bountiful harvest. However, our ancestors didn’t know how composting worked and why it worked.
You may be familiar with the benefits of composting especially for gardeners and farmers. But if you’re not aware of how the composting process works, worry not.
Next, we will look at what happens in a compost pile.
Specifically, we will examine the role played by aerobic decomposition in composting, the necessary components in speeding up the decomposition process, as well as the various macro and microorganisms that carry out bulk of the work.
Breaking down of organic matter with the presence of oxygen is called aerobic decomposition, one of the most common processes in nature.
This is the type of decomposition you want taking place in your compost pit.
With aerobic decomposition, organic matter is broken down cleanly into carbon dioxide, minerals, and humus that your plants are sure to love.
Moreover, compost made through aerobic decomposition will have oxygen-loving microbes that are sure to fit and thrive in your plants’ preferred habitat.
And unlike its anaerobic (decomposition without oxygen) counterpart, aerobic decomposition doesn’t produce methane and foul smells.
Throughout this brief section, we kept mentioning beneficial microbes and how to encourage their growth and productivity. A compost pile will contain countless macro and microorganisms that are important for decomposition.
Bacteria, fungi, and its microscopic cousins are categorised as chemical decomposers, changing the chemistry of organic wastes as they go about their way.
Larger organisms, on the other hand, like mites, centipedes, and earthworms are known as physical decomposers – grinding, biting, tearing, and chewing the waste into smaller bits.
But of all the residents in a compost pit, the must-have decomposers are aerobic bacteria for many reasons: they’re the most rapid and efficient decomposers, and they excrete nitrogen, magnesium, phosphorus, and other nutrients plants need.
The aerobic bacteria consume carbon for energy and nitrogen so they can grow and continue to reproduce. They oxidise the organic waste in the pit. When the conditions are perfect, the compost pile increases in temperature as they consume the decomposable materials contained.
But should oxygen levels dwindle or any of the 4 success factors mentioned below changes for the worse, the aerobic bacteria may slow down in activity or even die, allowing anaerobic microorganisms to take over. These not-so-welcome microbes produce useless acids instead of plant nutrients. Not only are these acids smelly, they can be toxic to plants in some cases too.
Successful and efficient decomposition of organic waste in a compost pile depends on a number of factors: presence of oxygen, moisture, particle size, and temperature. If one of these factors is lagging behind the rest, the microbial activity slows down and so does the composting process.
Aerobic microorganisms need oxygen to efficiently break down organic waste. Oxygen levels of about 5% must be maintained throughout the pile. Failing to do so can cause the compost pile to switch to anaerobic decomposition, which leads to a pile that stinks, produces methane, and takes 3 to 4 times longer to break down.
To prevent that, turn and mix the compost pile once or twice a month to allow oxygen to penetrate. You can also add coarse materials to create air passages at the bottom of your pile.
Dry compost will NOT break down efficiently. The microbes in the pile need moisture for growth and reproduction. If rainfall is hard to come by in your area, periodically water the pile so it’s damp but not soggy.
Excessive watering can block the tiny air spaces in the pile, and prevent oxygen from penetrating. If the compost gets too wet by accident, turn it until it dries out.
The beneficial microorganisms will have an easier time breaking down the organic waste if they’re sliced and diced into bits. Whether it's kitchen or garden waste you’re adding into the compost, always shred or chop the waste beforehand.
This is important to the microbial activity taking place in the pile. The microorganisms that do most of the legwork in the decomposition process thrive in higher temperatures, and exposing them to low temperatures outside the pile will slow down their activity.
Fortunately, you don’t need to do anything extra to increase the compost’s temperature – aside from constantly adding well-mixed organic waste. The microbes will feed on the organic matter you add, and as they do, the compost pile’s temperature reaches 44 to 71°C, also enough to eliminate many of the pathogens and harmful bacteria present.
In the previous sections, we looked at the unbeatable benefits of composting, the process of decomposition, as well as suitable composting materials you can easily find around your home.
Next, we will look at a handful of composting methods that you may want to try depending on where you live, the space you have, and the amount of work you want to put into it.
Whether you’re living in a farm with wide open spaces, in an urban location with a spacious backyard, or a minimalistic apartment, you’ll find a composting method that suits you.
This method is a favorite by many as it can easily do both hot and cold composting. Constructing open composting bins is fairly easy, and only wire fencing and wood are used to create an open structured area to put your organic waste.
The wide open nature of these composting bins accommodates large volumes of waste while making it a breeze to turn the compost, which is essential to speed up decomposition. Moreover, open bins allow air to penetrate and circulate through the stockpile of organic matter, something that the aerobic microbes will surely love!
The downside with open composting bins, however, is it can be expensive. It may also require a lot of space depending on the number of bins you want to build. If you’re living in the city where backyard space is hard to come by, check out the other composting options discussed in this section.
Do you know what makes composting labor-intensive? It’s the need for frequent turning to encourage aeration. With tumblers however, turning compost becomes a less labor-intensive task.
The tumblers are usually made of plastic, attached to a structure that raises them off the ground. With this set-up, you can easily turn the whole tumbler even with one hand. And thanks to its closed nature (unlike open bins) and smaller space requirements, tumblers are a good choice for composting on urban areas.
However, this method has its share of downsides. For starters, it’s off the ground which means soil organisms can’t reach it. You need to add a bag of soil to the mix to help increase the diversity of the microorganisms in the tumbler.
Moreover, tumblers are not a good choice for hot composting. They’re unreliable as it’s almost impossible to maintain its temperature, which is necessary for killing weeds, disease-causing pathogens, and other harmful organisms in the waste.
If you want to cut your costs down to zero and you have the space for it, piling is a highly recommended method. As the name suggests, it doesn’t require any bins, tumblers, or other containers. You simply pile all of your readily decomposable waste somewhere in your backyard and that’s it! All you need is a pitchfork for turning the compost.
However, this method is not for everyone. If you’re in a small urban location, the compost pile may be impossible to camouflage – and a heap of decomposing organic waste isn’t pleasant to the eyes.
This composting method uses worms for faster decomposition using as little space as possible. And it’s very easy to do: simply bury your organic waste under a moist bedding material made of leaves, straw, or shredded paper, and let the friendly worms do their magic. Even better, worm compost can even prevent plant diseases and regulate plant nutrients as shown by research!
Composting with worms is an excellent option if you’re living in small spaces. The compact design of popular vermicomposting kits can fit just about anywhere: in a corner of an apartment, somewhere in the basement, garage, or under the sink.
Alright, this isn’t a composting method per se.
But if you’re a gardener who can’t afford to wait 3 to 12 months for your organic waste to decompose, buying from a reputable seller instead is a quick way to get your hands on a bag of much needed compost.
When shopping however, be discerning don’t just settle for any bag of compost. For starters, keep an eye on the packaging. If it’s faded or looks old, avoid it. You also want to check the ingredients. Many composts for sale are only made of decomposed wood, which is severely lacking in nutrients and other microscopic good stuff found in composts made from a variety of sources.
Need compost fast? No problem! Here at Grabco, we sell high quality topsoil and compost at quantities you need and prices you can afford! Give us a call or shoot us an email, and one of our trained, friendly representatives will help you with your order!
Just about any organic material is a good addition to your compost pile.
However, your compost pile requires the proper ratio between carbon-rich (or browns) and nitrogen-rich (the greens) materials.
Mixing organic materials and tweaking the carbon-to-nitrogen ratio can make a huge difference in your compost pile, particularly in its rate of decomposition.
Add too much carbon and the decomposition process becomes slow as molasses. Too much nitrogen, on the other hand, will cause terrible odor – so terrible simply lifting the lid becomes a struggle!
Later in this section, we will look into the science behind carbon and nitrogen balance – and how getting the ratio right is essential for successful composting. We’ll also discuss the types of organic materials that are suitable for your compost pile – and which materials you should avoid and why.
Excited? Let’s get on it!
Any organic material that goes into your compost pile contains a ratio of carbon and nitrogen – and both are essential for the survival and proliferation of the microorganisms in your pile, which are in turn responsible for the decomposition of the grass clippings, fresh leaves, food scraps, and other organic contents of your compost.
Carbon serves as the building block of life and the primary source of energy. Nitrogen, on the other hand, is essential for meeting the microorganisms’ protein demands while maintaining their genetic material and cell structure.
Perhaps you hardly pay attention to the carbon and nitrogen content of your waste. Waste is waste after all! But if you want to successfully compost and reap its benefits, you can’t disregard the carbon and nitrogen content of your compost materials.
Excess carbon-rich matter in your compost pile will surely stuff the microorganisms in your pile, but the decomposition rate will slow down significantly as the decomposing bacteria need nitrogen to get to work and expand its population.
Having too much nitrogen-rich matter, on the other hand, will cause the microorganisms to work too hard and use all of the available oxygen. The lack of oxygen in the compost allows anaerobic bacteria to take over, converting the excess nitrogen into ammonia gas and causing a sour, foul smell!
Just like us humans, the decomposing bacteria in your compost need a balanced diet. And in the next section, we’ll look at how to give these friendly microorganisms the carbon and nitrogen content so they can stay healthy, reproduce, and decompose the stuff in your pile at a reasonable rate.
You want a compost pile with a carbon-to-nitrogen ratio of 30:1 ideally. Such a ratio leads to a temperature of up to 60°C with the organic materials in the pile decomposing at an ideal rate.
However, achieving the ideal carbon-to-nitrogen ratio is not always possible.
And one more thing: don’t make the mistake of taking the ideal ratio as volume. The carbon-to-nitrogen ratio given above refers to the chemical composition of the materials that go into your pit – not the volume!
If you want to base your compost pit’s ratio on the volume of organic matter that goes into it, go for a 2:1 ratio – 2 parts of carbon-rich material for 1 part of nitrogen-rich matter. This is good enough to achieve a carbon-to-nitrogen ratio of 30:1 up to 50:1.
Now that you have a clearer idea of what the compost bacteria needs and how much, we’ll now look at various organic materials to add in your compost, any special handling required, and the materials to avoid in composting.
Listing every composting material around is impossible – there are thousands of suitable organic materials around! So instead, we list 3 broad categories of organic waste to guide you in your selection of composting materials.
Even better, these types of organic waste are easily found around the house so you’ll never run out of stuff to compost!
Tea bags, fruit peelings, apple cores, and just about anything that cycles in your kitchen belong to this category. The UK generates about 6.7 million tonnes of food waste every year, which costs £10.2 billion ($12.7 billon) to dispose. The United States, on the other hand, 30-40% of food is wasted, which translates to over 20lbs of food waste per person every month.
A crying shame since we can easily cut the amount of food we squander and the money we spend on waste management by putting all of our food scraps into a compost pile.
You can easily collect all of your kitchen waste by having a compost pail in your kitchen. To keep the flies and pests away from the pail, be sure to keep a lid on the container and cover the food scraps with about 8 inches of carbon-rich material. Once the pail is full, bring the contents to the pile, and rinse and repeat.
A word of warning: meat, dairy products, and foods with high fat content are suitable for composting but can cause problems when handled improperly.
For starters, they can smell really bad and attract pests. So be sure to chop them into tiny pieces and cover them with carbon-rich matter.
Eggshells too are a great compost addition as they’re rich in calcium, a nutrient plants need to build cell walls. The problem with egg shells, however, is they decompose very slowly. So crush the shells before adding to your compost to speed up the decaying process.
Yes, it stinks. But manure is also one of the best composting materials out there as it is rich in nitrogen and helpful bacteria.
However, you want to stick with manure from herbivores like cows, horses, sheep, ducks, etc. You don’t want to add droppings from carnivores like cats and dogs as they might contain parasites and infectious diseases.
If you have a pet dog and insist on using dog waste for compost, reading the study and recommendations from the Fairbanks Soil and Water Conservation District and the USDA would be a good idea. Dog waste composting is possible but only with great care – and even then, it’s not recommended for crops grown for consumption.
But whatever type of manure you plan to compost, be sure to let it age first. Fresh, hot droppings are jam-packed with nutrients and may overheat the compost pile, killing the decomposing microbes and friendly worms. Giving the droppings enough time to age makes them safe for use, while adding brown materials help keep the pile’s carbon-to-nitrogen ratio balanced.
Grass clippings, dead planned, deadheaded flowers, seedling leftovers, and other garden waste make for excellent compost materials.
Grass clippings, in particular, are just as nitrogen-rich as manure. However, be warned that fresh grass clippings easily clump together.
And when they do, oxygen will have a hard time penetrating, and the clippings become anaerobic and start to smell.
Be sure to add a lot of carbon-based material into the mix when composting grass trimmings.
You should also bake the clippings under the sun for at least a day. Simply spread the clippings over a smooth surface that gets a lot of sunlight, and leave them there until they turn pale.
Once baked and dried, you can add them into the pile minus the risk of souring. Oh! And one more reminder, steer clear from grass clippings that contain pesticides or herbicides.
Dead weeds and their seeds, on the other hand, can be a suitable compost material as most weeds are killed when the pile reaches an internal temperature of 54˚C. But that’s not guaranteed. Weeds with persistent root systems can still survive under such temperatures, so be discerning when using weed for composting.
Be extra careful in composting plants that died due to a disease. You need an efficient composting system and extreme heat to get rid of the pathogens in the plants. If the disease-causing microbes are not destroyed, you run the risk of spreading the plant disease when you apply compost in your garden.
If you don’t want to omit dead plants from your menu of composting materials, be sure to sun-bake them in plastic bags for at least a week or until they’re absolutely dried. Or better yet, burn the plants and put the ashes in the compost pile for good measure.
You want to stimulate the composting process in your back garden. The faster the organic matter decomposes, the sooner you can add much-needed compost to your garden. To speed up the decaying process, you need to increase its internal temperature, which favours the decomposing microbes.
And here are 4 tips to do just that:
We’ve discussed the benefits of composting, the ever-important carbon-to-nitrogen ratio, suitable composting materials and methods, and many more. In this section, we will look at the numerous ways of using the finished product to enhance your garden and plants.
Now, you might be asking: “How can I tell if the compost is finished?”
There are a few tell-tale signs to look for. If your compost dons a dark, rich colour and a sweet, earthy smell, it’s finished. Furthermore, finished compost has a crumbly texture and it’s impossible to pick any of the original ingredients out.
If your compost is still lumpy and smells stingy, you need to give the microbes a bit more time to finish their decomposing job.
Compost can take 3 to 12 months to reach the finished product, and this depends on a number of factors: the temperature, organic materials used, the type of compost bin, the fineness of the materials, turning frequency, and more.
Yes, making compost takes time. But once done, you can add compost to your soil any time you want, and reap the rewards without fear of stressing plants and polluting water. Without further ado, let’s take a look at 4 different ways to put your compost to good use.
Compost makes for a great all-natural amendment that can greatly improve the soil’s physical, chemical, and biological properties.
It improves the water-retention capacity of free-draining sandy soils, preventing drought damage to plants especially during warm seasons. Adding compost to heavy and dense clay soils, on the other hand, improve the drainage and air-retention while preventing water-logging.
Moreover, the addition of compost improves the soil’s ability to retain and release plant nutrients while encouraging the activity of earthworms and proliferation of beneficial soil microorganisms.
Here’s how to add compost as a garden soil amendment:
For new garden beds, adding 3 to 6 inches of compost over the entire bed’s surface is highly recommended. Mix the compost up to a depth of 6 to 8 inches into your soil. Make sure it’s blended well so the entire garden bed has a good, almost even mixture of soil and compost.
If you’re adding compost to existing garden beds, apply 1 to 3 inches of compost over the surface, and work it into the soil at a depth of 3 to 4 inches. And that’s it! No need to go deeper as the earthworms underneath the garden bed will do the digging and further amending for you.
Warning: use only finished compost for best results. Applying unfinished compost as an amendment can cause plant stress (characterised by stalled growth and yellow leaves) as the organic material is still decomposing. The microorganisms in the compost are not done with their work – which means they’re competing with plants for nitrogen.
Mulching, while not mandatory, is a great gardening habit to cultivate. Adding mulch to your garden soil offers unbeatable benefits including:
Inorganic materials like gravel, black plastic sheets, and even newspaper make for good mulch. But when you use an all-organic material like compost for mulching, you get all of the benefits mentioned above – plus a lot more!
Compost as mulch not only moderates the ground’s temperature and protects plant roots. It also constantly improves the soil with its nitrogen and carbon content as water runs through the compost during the rainy season.
To apply finished or unfinished compost mulch, start by spreading compost over the soil’s surface, maintaining a thickness of 3 to 4 inches.
Remember: do not mix the mulch into the soil especially if you’re using unfinished mulch. Furthermore, the compost must be kept 2 to 3 inches away from plant stems. By doing so, the nutrients will slowly filter into the soil without the compost microbes robbing the plants of nitrogen.
Using compost as mulch has one disadvantage you must be aware of: it doesn’t prevent weed growth – and may even promote it! To work around this, cover the compost with standard mulch material.
If you’re into container gardening, then you’re familiar with the great importance of soil preparation for potted plants.
Get the potting mix right and you’ll be rewarded with thriving plants and even colorful blooms. Blow off soil preparation and you’ll end up with non-productive, dull plants that require great care to survive and are susceptible to diseases.
Potted plants require soil that can retain moisture and nutrients while draining well. And finished compost fits the bill.
It boasts good water retention properties and contains nitrogen, carbon, and other essential nutrients. Not to mention it can easily blend with other materials like coarse sand to create an ideal planting mix.
To use compost as a potting mix, getting rid of the large chunks is the first order of the day. You can filter the big chunks (and un-decomposed matter) by running the compost through a half-inch screen. You want to leave a bit of the coarse and bulky matter in the compost to improve the mix’s draining properties.
Compost tea is often called “black liquid gold” and for good reason.
It’s an amazing fertiliser for your garden – and one without the chemicals and high-salt content found in commercial synthetic fertilisers which can change your soil’s physical and chemical properties for the worse.
Instead, compost tea contains nutrients that your soil and plants will surely love!
Using compost as a tea or liquid fertiliser offers numerous advantages: it’s teeming with micronutrients and can be easily absorbed through the roots and leaves.
Moreover, compost in liquid form doesn’t take up space during application unlike its original form, making it a suitable fertiliser for container plants where you may not have enough space to add compost in solid state.
Creating a compost liquid fertiliser is akin to making tea in your kitchen:
Old World Garden Farms has a detailed guide on how they make their compost tea and use it for watering plants.
They recommend watering plants with compost tea using a garden sprayer or watering can every 2 weeks after the plants were established. When watering, soak the area near the roots and sprinkle some of the compost tea on the leaves too for good measure.
For best results, apply the compost tea early in the day before the sun is up and shining to avoid burning the leaves of the plants. About 4 to 6 applications of the compost liquid fertiliser is enough for bountiful yields.