From leaf mold and mulch to manure, here's how to enrich your garden using the garden itself.The goal for any sustainable gardener should be to create closed-loop systems—where the garden can be maintained without the need for many, if any, external inputs. In other words, wherever possible, we should aim to create a garden that can support and sustain itself over time. 

This internal sustainability is especially important to think about when it comes to garden fertility. Fortunately, there are plenty of potential sources of organic garden fertilizer that can be found in your home and garden. 

When we use these sources of garden fertilizer, we can maintain healthy soils and keep our gardens beautiful and productive over time without having to spend money on commercial products.

Homemade Compost

One of the most important ways to recycle nutrients in your garden and to maintain a healthy soil ecosystem is to make your own compost at home. 

Composting is not hugely complex. After all, this is something that happens naturally all the time without our intervention. But choosing the right composting strategy for our situations and where we live can be important. 

We might choose to compost in place in no-dig gardening systems. We might have a simple cold composting heap or bin. We might also speed things up with hot composting, using a compost tumbler, or by enlisting the help of special composting worms and taking up vermicomposting.

Compost is an excellent soil amender and is also a good source of organic matter to replenish nutrients in the soil and provide a slow-release fertilizer for plants.

Leaf Mold

Homemade garden compost heap with leaf mold for use as organic fertilizer.

Leaf mold is another excellent source of nutrients for plants and a great amendment for soil when, like compost, it is laid as a mulch over our growing areas. This is a partially decomposed material made from autumn leaves that are gathered up and left to break down for a year or two. 

Spreading leaf mold on the soil or using it to top dress pots and containers can, again, slowly release nutrients for plants to take up over time. And it can generally help to improve the soil to allow for good plant health.

Mulch Materials

In addition to thinking about brown organic materials like compost and leaf mold, ensuring good fertility in an organic garden also means looking at green mulches, or chopped and dropped plant materials. These, too, can be very important to maintaining fertility in an organic garden. 

Green leafy materials such as grass clippings or green leaves from other plants—even weeds that are chopped and dropped onto the surface of the soil, will break down and return the fertility they contain to the system. 

Some plants are good at gathering certain nutrients and storing them in their plant tissues. These plants can be particularly efficacious as mulches in specific contexts—helping to address nutrient deficiencies in certain parts of your garden, for example. Or providing more of a particular nutrient for plants that require it. 

Tailoring the mulch materials we use to the soils in our gardens and the plants we are growing can help us fertilize plants naturally and effectively.

Liquid Plant Feeds

Bokashi composting supplies eco-friendly liquid fertilizer.

Different plant materials and compost can also be used to make organic liquid fertilizers for our plants. Liquid plant feeds serve a different purpose than mulches of organic matter. 

While mulches and compost are slow-release fertilizers, liquid feeds release nutrients for a much quicker uptake to give plants a boost. They can be particularly useful when growing plants in pots or other containers. But they can also increase yields when used in other garden areas. 

Again, it is important to tailor the liquid plant feeds that we use to the needs of specific plants we are growing—thinking carefully, for example, about whether the plants need a nitrogen-rich, balanced, or potassium-rich feed. 

Well-Rotted Manure

Last but not least, our gardens might also be spaces where we keep pets or livestock that provide us with their manure (often in addition to other yields). 

Many people keep backyard chickens, ducks, or other poultry, for example, whose manure can be a good source of fertilizer once well-rotted and composted first. Some may also consider rabbits, whose manure can even be used in the garden without composting.

If you plan your garden well, however, whether you keep animals in your garden or not, you should still be able to find a range of sources of organic garden fertilizer very close to home and be able to keep your garden growing strong.