Getting started with vermicomposting in Singapore

Worm poo. “It’s like liquid gold for plants!” …or so I’ve been told. It seems that gardening is not one of my natural talents. After nearly four years in our ground floor apartment, I’ve just about got the hang of keeping the plants alive, but am still struggling to cultivate my Pinterest-inspired, tropical-paradise outdoor space. So when I read about how amazing vermicast (the more elegant name for worm poo) is for plant growth…I decided it was worth a shot. The kids had been bugging me for a pet anyway so I figured this would kill two birds with one stone. With the added green credentials of composting to boot!

However, like many city dwellers, I hesitated for quite a while before diving in. Would the compost bin smell disgusting? Would we be attracting hordes of pests and rodents to the patio? Would we accidentally kill all the worms or might they all escape, shrivel up and die all over the floor? Daddy Chu was especially concerned about this last possibility.

But one fine day, I noticed someone selling a fully established vermicomposting bin online (they were leaving Singapore) and decided to take it off his hands on the condition that I could ask for any advice I needed. It was a lot easier not having to start from scratch, and so far, its been working out well! Surprisingly, it doesn’t smell at all, and apart from a few fruit flies, we haven’t had any other pests showing interest in the compost bin. Our worms have multiplied so fast – we’ve set up a second identical bin in under 2 months.

Little Miss is particularly fond of the worms, and since her big sis has been inundated with P4 exams lately, she gamely took over the lead for this month’s EveryChusDay video:

There are many fancy vermicomposting systems on the market, some of which are pretty expensive, and it’s hard to know which will suit your needs and space best before you get started. However, you can DIY a basic setup with a couple of plastic boxes and accessories from the hardware store at minimal cost.

The main hurdle is to create an environment for your worms to thrive. I cheated a bit, by buying an up-and-running bin, but now that we’ve learnt a bit about how to keep the worms happy we thought we would share our personal experiences so far for any would-be vermicomposters out there. It can be daunting to get started despite the abundance of information online. I found joining a Singapore Vermicomposting Facebook group was very helpful!

Worms – species and quantity

Not all earthworms are good composters! There are a few worm species that are vermicomposting favourites, common ones being Red Wrigglers, African Night Crawlers and Malaysian Blue worms. Our box came with Malaysian Blue worms, which have a great appetite and reproduce relatively fast. They are a good choice for efficient composting in the tropics as they are happiest in relatively warm climes. If you live somewhere with wider temperature extremes, you would be better off with Red Wrigglers or similar.

In terms of numbers, apparently an optimum worm density for composting is approx 5-10kg worms / sqm surface area of bin. If your worm density is lower, worms may not meet and reproduce much. If it’s too high, the worms will also stop reproducing in response to overcrowding. To be honest, I have no idea what the worm density of our bin is. We tried counting, but gave up after about two hundred…it was just too tedious! But after noticing quite a lot of young worms crawling around recently, we decided they had multiplied sufficiently to start up another bin. If we ever get round to determining our worm density I will update this post!

Environment

The contents of your composting bin may vary a bit depending on the worms you use, but the main factors you need to consider are temperature, moisture and acidity (pH).

Find out what temperature range is suitable for your worms, and keep the bin in a shady or dark area away from direct sunlight. You also need to consider where to bury your food scraps as the process of decomposition releases heat. We bury ours near the surface to allow heat to dissipate easily and give the worms a cooler region below which they can retreat to if it gets hot above.

The soil / bedding must ben kept damp (“squeezed-out sponge” damp) – too wet and worms will try and escape; too dry and worms will not be able to breathe (oxygen from surrounding moisture diffuses in through their skin). So make sure your bin can’t be flooded by rain if left outdoors. The main bin should have drainage holes at the base to prevent waterlogging. Add water carefully if the soil feels like it’s drying out.

I have never checked the soil pH of our bin, but apparently most worms like a pretty neutral (ph6 or 7) soil. We avoid putting in citrus fruits as this might make the soil too acidic, which can irritate worm skin and also cause the bin to smell bad.

Another factor which helps foster a happy worm bin is the presence of a wide range of micro-organisms which help with the decomposition process. In fact, the worms need their food to be partially decomposed by these little friends before they can even get started on eating. If you’re setting up a bin from scratch, I’m not 100% sure how you make sure there’s enough microbial activity to get food decomposing fast enough for the worms. Apparently, you shouldn’t put worms straight into a “sterile” bin – you need to prepare the bedding and microbial environment in advance before adding worms.

We see lots of little mites and springtails eating alongside the worms… these are generally helpful but you don’t want the populations to get out of hand. Making sure the soil isn’t too wet helps.

Things to consider are types of food, amounts and frequency of feeding. In terms of food “type”, worms like a mix of green (nitrogen-rich) and brown (carbon-rich) foods. Watch our video for details! There are also several items that should be avoided like meat, dairy, oily and processed foods. Some foods are not harmful to worms, but will cause the bin to smell bad (brassicas and alliums) so are also best avoided.

Feeding the worms

We collect our scrap food in a box in the fridge over the week and chop them into small pieces to speed up decomposition. Kids love chopping scraps and pounding up eggshells! Mouldy items seem to be fine too. Some vermicomposters freeze and thaw scraps to aid decomposition, some even microwave them before freezing to kill off bacteria / fruit fly eggs etc. which may be found on certain fruit peels. We haven’t bothered with these extra processes so far. It has been surprisingly satisfying to turn our organic waste into compost – and it has definitely made us much more aware of the amount of waste we produce in general.

We currently feed our worms every 4-5 days. However, they can go for quite a long time (around 3 weeks?) without being fed – so leaving your worms whilst you go on holiday shouldn’t really be a problem. I love low-maintenance pets.

Harvesting the vermicompost

I’m not sure if we are doing this part correctly. Currently we are simply scraping off the castings (each time we do a feed) from the surface of the bin and storing it to sprinkle on our plant beds. The castings are easy to spot as the texture is very squiggly and different from the rest of the soil. However, other vermicomposters appear to harvest the compost more infrequently by completely removing all the worms and using the whole bin of processed material as vermicompost. This is more time-consuming so we haven’t tried it yet. You can apparently also brew a potent “worm tea” using your vermicompost by aerating the compost with molasses in water. This creates a very rich fertiliser for plants as well, and is on my list of things to try soon.

So…has the vermicast boosted the lushness factor on our patio? It’s early days, but I dare say it seems to be helping. I have been using vermicast for top dressing. and mixed some into potting soil when repotting, growing from seed or propagating plants from cuttings. Our plants seem to be growing quite quickly, and some plants which haven’t flowered in a while have started budding. I have also managed to get some plants growing successfully from seed and cuttings which I rarely seemed able to in the past. So although the effects have not been rigorously studied, I do think our little tropical paradise is moving in the right direction!

In fact, we were visited by a couple of large hornbills the other day who showed a little too much interest in our juicy-looking lime bush, which I’ve been liberally sprinkling with vermicast. I’m taking that as an early sign of success.

*If any readers have any advice to share, please do comment below! All suggestions will be much appreciated as we are just getting started and definitely still have a lot to learn.