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Organic Compost DIY

Zhou Miao-Fei
Translated by Gan Ruyu

Due to the dense population in Taiwan, most people here live in apartments or tall buildings. Those who love gardening would certainly grow their plants in flowerpots of all sizes. How then does one get planting soil and compost? What is compost?

In fact, we can make organic compost in flowerpots. The ingredients are our kitchen scraps and plant-based wastes from our home. By recycling these free ingredients, we can create organic compost that is rich in nutrients, aerating and moisture absorbing. This is the best type of planting soil.

So what do we need? First of all, prepare several flowerpots. It doesn’t matter if they are old or new, big or small, although the bigger ones can produce a faster and better result. The size of the pot and how many to use depends on the volume of your kitchen scraps and plant-based wastes. There should be drainage holes at the bottom of the pots to facilitate aeration and drainage.

The pots should have plates that are neither too small nor shallow. You can add a bit of water in the plate to prevent ants. The plates can also hold the liquid occasionally drained from the pots. If the pot is placed directly on earth, then you don’t need the plate. You can place the pot next to a fruit tree or grow some plants around the pot. The liquid drained from the pot is top quality liquid fertilizer. You can use it to water your plants. Never throw it away.

Next prepare a bucket of soil for covering the kitchen scraps and plant-based wastes. Any type of soil will do. If you don’t have soil, you can buy the cheapest planting soil or coconut husks (you should be able to get it at nurseries. The husks are crushed into brick form that will expand after being soaked in water).

Next is the material for covering the pot. The main purpose is to prevent the moisture inside the pot from evaporating. It will also stop the nutrients from being washed off by rainwater. Be creative. Just make use of “junks”. Cut a piece of wire mesh, covered with a piece of thick cardboard, and then add a piece of brick as weight. This is the practical way. Cut a larger piece of transparent plastic sheet and let the edge droop down the side of the pot. Your child can observe the natural transformation inside the pot. This is the educational way. Or like me, just cut a piece of old useless carpet to cover the pot. This is the lazy way.

The best ingredients for making compost are plant-based. Don’t use meat scraps, dairy products and oily kitchen scraps. They produce foul smell and attract harmful insects. Plant-based compost, at the most, will just attract harmless fruit flies, ants and other insects. It will produce a fresh, earthy smell like humus in the forest. The finished compost is also full of effective microorganisms that will improve degraded soil.

Plant-based kitchen scraps include old leaves, stems, roots or skin of veggies; all fruit peels (watermelons, mangoes, bananas, passion fruits, etc.); fruit flesh (apples, muskmelons, guavas, etc.); eggshells, groundnut shells, etc. Plant-based wastes include flower stems from cuttings and withered flowers, leaves and twigs from pruning, shredded papers, dust collected in the vacuum bag, weeds, etc.

The ingredients will work better if cut into smaller pieces. Those in green color and contain more moisture will decompose faster. With the high temperature in summer, a big piece of watermelon skin can fully decompose in one to two weeks. Those in dark brown, more woody and harder type such as branches, tough fruit peels and dried leaves decompose slower and less thoroughly. But they can still improve soil and hold moisture and nutrients.

My friend has a big garden and is always troubled about getting rid of fallen leaves. Now the leaves are one of the ingredients for my compost. In autumn, sweeping the public pathways can also bring me one big bag of fallen leaves. All plant-type “garbage” can be good ingredients for making compost.

Start by filling the pot with 5cm of soil or coconut husks. Then add in kitchen scraps and plant-based wastes. Covered with a few spades of soil. Be generous. Don’t just sprinkle a thin layer. The soil can absorb water and prevent flies and insects. Then sprinkle some water and cover the pot.

How much water to sprinkle? This is hard to say. Some kitchen scraps with higher moisture content can do with less water; drier ingredients or on drier days would require more water. If you ask your granny and mother how much salt and sauce they add in the cooking, they will certainly answer, “Roughly. Something like that.” But such an answer contains much experience and love! Anyway, the ingredients should feel like a squeezed sponge – moist but airy – that would be perfect. Don’t worry if it’s too much or too little, they can be adjusted at all times anyway. When there is too much water, it will drain from the holes at the bottom of the pot. You can also turn the soil, remove the cover, let the water evaporate a bit, or add more soil to absorb the water. When there is too little water, just sprinkle a bit more. Simple!

The next day you get another batch of ingredients. If you want them to turn into compost faster, chop the scraps into smaller pieces and throw them into the pot. Similarly, covered with soil, sprinkle some water and cover the pot. Your daily kitchen scraps and plant-based wastes from your home can be added into the pot layer by layer like a sandwich. Each time you add a layer, if you’re keen, you can turn the soil a little to aerate it. This will speed up the decomposition process. If it doesn’t have enough air or is too damp, it will produce foul smell. Top up the layers until the pot is full, then keep it covered and wait for it to turn into compost. Check on it once a week. If the ingredients are very dry, sprinkle some water every now and then to keep it moist. The time it takes to fill up the pot depends on the pot’s size and how much ingredients you have.

Then you can start another pot. Start by filling the second pot with 5cm of soil or coconut husks, add in the scraps, covered with soil, sprinkle some water, cover the pot, repeat until the pot is filled. Similarly, sprinkle some water occasionally to maintain the moisture. Then start your third pot.

For your third pot, add in 5cm of soil or coconut husk as before, add in the kitchen scraps and plant-based wastes, covered with soil, sprinkle some water, and keep layering like a sandwich. Is it ever going to end?… you might start to wonder now.

If you only have scraps like leafy veggies and fruit peels, and your pot has a diameter and depth of at least 50cm, during the hot summer when you’re making your third pot, you’ll find that your first pot is already nearly completed. The originally filled pot is now only half full. Turn it with your spade and you’ll find that the kitchen scraps are now gone. What’s left is something black, crumbly, soft and light, which you can use as fertilizer or planting soil. If you have a lot of twigs, leaves and weeds with a small pot during the cooler season, by the time you’re making your third pot, the first pot may not have fully decomposed yet. But if you see any black and crumbly material in the first pot, you can still retrieve it to use as fertilizer or planting soil. It won’t harm the plants’ roots. So even if it’s not fully decomposed yet, you can still use it.

How to use it? Organic gardeners get very excited over self-made compost, because it can turn the most degraded soil into the most fertile one. Therefore cherish your compost once it’s done. It contains all sorts of effective microorganisms that can’t be seen with naked eyes. But there are countless of them that will benefit you, others and improve our ecology.

You can scatter the finished compost around all types of plants as fertilizer. You’ll find that the plants are soon filled with vigor. For example, the flowering plants will produce even more vibrant and beautiful flowers. You can also use the compost for germinating seeds or raising seedlings. Besides planting, you can use the compost as a source of friendly bacteria. With your third pot of compost, every time you add the kitchen scraps and plant-based wastes, you can scatter a handful of compost from the first pot, then cover with soil and sprinkle with water. You’ll find that the decomposition is faster and more thoroughly. Self-made compost is like the gold of gardening. It brings nothing but countless benefits.

When your third pot is filled, you can continue with your fourth pot, fifth pot,… or go back to your first pot. If you didn’t use your first pot, when you’re starting your fourth pot, the decomposition of your first pot is even more thorough. And your second pot should be almost decomposed by now. Of course, if you have lots of ingredients and your pots are small, you may need to continue filling your fourth and fifth pot before your first pot is thoroughly decomposed. A small pot of little volume cannot produce enough heat. The decomposition will be slower and less thorough. However, it can still be used. You don’t have to worry if the effects will be lesser or if it will harm the plants.

If the compost from the first pot is almost used up, keep some as compost “activator” and reuse the first pot. Keep some compost in the pot, add new kitchen scraps and organic wastes, sprinkle a handful of the compost from the first batch, cover with soil, sprinkle some water, and repeat the layers. By now the second pot is nearly completed, and you may start using the compost from this second pot. When it’s used up, start layering in this second pot and start using the compost from the third pot. Once the first pot is filled, maintain its moisture and let it decompose. When the second pot is filled, start layering the third pot, and use the compost from the first pot.

When you’re using this three-pot cycle and the decomposition is not thorough, you can use a four-pot, five-pot, or six-pot cycle. Therefore you can repeat using the flowerpots; you can reduce the organic wastes from your family; you can continuously create organic compost. If you’re not keeping plants at home, you can give your compost to friends or fertilize the plants in the nearby park. The next time you go there, you’ll find that the plants are greeting you happily.

I don’t have much space at home. So I don’t cover the flowerpots that I use to make compost. I like to fully utilize these pots of compost.

I love to sow seeds in the flowerpot that is filled with compost-making ingredients. On the top last layer, I add another layer of planting soil of about 5cm. I sow the seeds and cover them with some soil. I water it daily. In this way, I’m making compost while raising seedlings. I use the liquid drained from the bottom of the pot to water other plants. The biggest benefit of raising seeds on the top layer is that the composting process generates heat. It’s like a warm blanket in winter to help the seeds germinate faster. Raising seedlings in the big pot also helps prevent pest and maintain moisture. When you’re raising seedlings, take note that their roots are still tender. The pot should be placed under the shade or at a bright spot without direct sunlight. The soil must be kept moist.

When the seeds start germinating a few days later, you’ll notice that the soil is slowly sinking. Two to three weeks later when the seedlings have four to six leaves, you may transplant them. I’ve found that by using old chopsticks to transplant the seedlings, it causes the least harm to the tender roots. You can also dig in with your fingers and scoop up the soil around the seedling. You may find that the seedling have deep healthy roots that extend into the compost. Keep all the roots intact while transplanting. Therefore sow the seeds apart. When transplanting, include all the soil around the seedling and its roots (some deep roots may be longer than the seedling itself, so dig deeper). As the compost is crumbly, it prevents the roots from entangling and breaking. Once transplanted, the seedlings will soon grow up strong and healthy.

After transplanting the seedlings, you have half a pot of half-decomposed compost. As mentioned before, I’ll use it as compost activator or spread it around the plants as fertilizer, or use it to grow vegetables. When I’m planting vegetables, I’ll first make compost in the pot. Fill the pot with a layer of soil, a layer of kitchen scraps and organic wastes, a thin layer of compost and so on. When the layering reaches 2/3 of the pot, I’ll fill the remaining space with the half-decomposed compost. Then I’ll dig a few holes and transplant the veggie seedlings into the half-decomposed compost layer. I’m killing three birds with one stone – recycling kitchen scraps, making compost and growing veggies. Oh, the liquid drained out from the bottom is used as liquid fertilizer. So it should be killing four birds with one stone!

If the veggie seedlings get crowded as they grow bigger, I pluck some from in between to make fresh green salad. Let the remaining seedlings reach their full growth. If they get crowded again, pluck some again for eating, let the rest keep growing. This way you get a continuous supply of fresh greens. Don’t forget, the old leaves and roots can be used to make compost. Once you’ve finished eating all the veggies, the soil can be used to cover the compost ingredients, recycling it into rich planting soil. You don’t need fertilizer with this method. But since our agricultural system has not been effective in recycling organic matters over the years, the vegetables and fruits that we consume currently are generally low in micronutrients compared to before. So for a few times a year, I like to add items rich in micronutrients such as seaweed and molasses to make up for the deficiency.

I have more than 20 big and small pots and polyfoam boxes for making compost continuously and repeatedly. Depending on needs and season, I sow seeds, transplant or pluck, keeping big and small seedlings for eating. So in this small garden of pots, some have just been sown with seeds, some transplanted, some with full-grown veggies for eating, some with veggies flowering for seeds saving. In short, I have an endless supply of organic veggies. Next, I’m thinking of using bigger pots to grow fruit trees.

After recycling and making compost like this for a while, you’ll find that the quality of the soil is getting richer and richer, and the plants are all healthy. If your soil comes from nature, or if you place your compost pot on earth, you’ll notice earthworms and other tiny organisms breeding there. They have moved in for the humus in the compost which is their food. Our kitchen scraps and organic wastes depend on them and other microorganisms to be broken down, digested, and turned into tiny particles that can be absorbed by the plants. The humus, small twigs and dried leaves that have not thoroughly decomposed are like sponge. They contain nutrients waiting to be absorbed by plants’ roots. As time passes, they gradually break down further and turn into tiny particles that can be absorbed directly by plants. This is how self-made organic compost supplies plants with the most perfect nutrients. And we will benefit from eating these self-grown veggies and fruits.

It may seem simple that we are just using some big pots to recycle our kitchen scraps and organic wastes, and turning them into organic compost for growing plants, but we’re actually creating a micro-ecological system. We’re helping to promote and fulfill our responsibility towards the planet’s ecology; we’re benefiting living beings and the environment. As we move along with this natural ecology, we’re benefiting our future and ourselves.

Original Chinese article is published in August 2008 issue of Lapis Lazuli Light magazine (Taiwan). It is available at http://www.lapislazuli.org/TradCh/magazine/200808/20080805.html