Wednesday, 29 April 2015


The soldiers have been here for 3 weeks today. And it's quite something how far we've come. Three weeks ago I caught two of the females who come every time we grind roasted cacao, and put them in a bucket along with some mango and banana peels and coffee grounds. Today I found two cascaras - the empty pupae skins. This I don't quite understand: according to my research it takes about 4 days for the eggs to hatch, two weeks for the larvae to grow - under ideal conditions, and then a further 3 weeks to a month for the fly to emerge from the pupae. I've been surprised even at how few of the pre-pupae I've seen 'crawl off' thinking that the environment wasn't ideal, too dry maybe. Obviously some decided to stay in the somewhat dry compost. This is the only thing I can think of as the whole situation was completely new and fresh 3 weeks ago.

I started with one bucket, which given how much mango and banana we've processed the last couple of weeks, quickly became 3. On Monday I went to the recycling center and came home with a nice cracked trash can which quickly became the home to the contents of all 3 buckets. There were so many grubs. So many. The bottoms of the buckets had became anaerobic - completely 'preserved' mango seeds and peels under a layer of black goo. Everything got shaken and stirred up going into the bin, so I think they'll be able to get to it. I'm so impressed by how quickly and how efficiently these soldiers polish everything off. The castings look great, almost ready for the garden.

The bin is full, and right now I'm not sure how much more I can feed. I've read that 100 pounds of scraps become 20 pounds of grubs and 5 pounds of compost/castings. I've certainly got a lot more than 5 lbs, and I'm quite sure I haven't put a full 100 pounds in there yet. So, what do I do? Wait for them to go through it again? It's true that I certainly overfed in the beginning - we just had so much fruit - so I'm thinking that the stuff in there can still be worked over.

I'm also wondering if I should make the bin wetter to ensure I don't have anyone pupating inside. Right now I'm not harvesting, but rather working on increasing the fly population (sounds odd doesn't it?), but it's something that will be happening fairly soon and I want everything operating smoothly.

So much fun. And I used to abhor maggots. Actually I still do somewhat, but now it's a morbid fascination. You can hear them eat, and watch the surface move with them. I sat fascinated on Saturday watching them devour a tomato. They had eaten everything but the very outermost skin - it was almost transparent and you could see their bodies through it. Yet it still looked like a tomato. Real horror show - one might say.

This is the Gardener Soldier Fly, much shorter - about ½ the length and less wide. Grubs are still as voracious though, and seem to mature earlier too.

And this is the Black Soldier Fly, this one is resting in the kitchen just by the chocolate making.

Monday, 27 April 2015

Duckweed update

It's been a couple of weeks of experimentation and observation. Actually it's been a lot of fun and has made me quite content to do nothing other than watch plants grow and things decompose.

The idea is to have a sustainable egg production. Sounds simple, but actually requires a bit of work. The farmer is agreeing to contained poultry - and that's what's making it more work. If they were free range then it would be all rather natural and easy. Instead they will be relying solely on humans for food and water. That's a shame really, but I think over time I'll be able to let them out. The plant man just needs reassurance that the feathered ones won't destroy the orchard. Patience.

So even though it's another month and a half until they arrive, and even though the site hasn't been fully cleared or the coop / run built, food production is under way.

We've planted spinach, pumpkin, pidgeon pea, moringa and a local green (chickens love it, no-one has a name for it) for fodder. Early days, but everything is coming up and looking good. Weather has been co-operating with sun and rains.

I have 3 tubs on the deck with duckweed and azolla. One tub has lots of leaf litter and tadpoles and gets about 4 hours of sun a day, one tub has just leaf litter and is in the shade, another tub contains Orinoco (my betta splendens) and is in more shade with indian almond leaf which makes the water soft and slightly acidic.

So far the tadpole tank is doing the best in terms of duckweed production. This is also the only tank with azolla, which is also doing well. We're not talking dense mats, but it is growing. I'd say doubling every 4 days. The azolla is slower, but also growing. Thus far I'm not at all confident that it will be the major green stuff in the birds' food. I need better production.

In all the research I've been doing there seems to be several "limiting factors", or variables: sunlight, nutrients in the water, temperature, hours of daylight. I'd also add munchers - something ate half my azolla when it was at ground level. Duckweed - it is said, prefers some shade, though in this case, it prefers a few hours of direct sun. The tadpole tub has probably the best nutrient rich water - both from the large number of tadpoles and the decaying leaf matter.

Initially I tried tubs with no leaf litter, no wildlife (that I could see), and added fermented pee to the water. Too much it seems. Not good. Since researching more it needs only 20mg of urine a liter, so my initial enthusiasm all but killed the plants. Unless I build a large tank I don't think the pee is an efficient idea, much as I like it.

I've also been reading that the effluent from black soldier fly larvae is also great for duckweed. It so happens that I have such an effluent, so another tub will in all likelihood get set up today to try that out.

I'd like to make a small duckweed pond by the coop, we'll have to wait til all the construction work is done for that.

I'm almost delighted that the most natural tank - with lots of leaf mulch and tadpoles, is the most successful. "Almost" delighted in that it's the one that requires the least participation, but of course quite delighted to see that Nature is always ultimately the most efficient, sustainable and long term winner.


Thursday, 16 April 2015

hill farm or home farm or upper farm? Importance of naming

I'm developing a new farm, a small, integrated, efficient and exciting facet of the larger farm. One that will no doubt take up a lot of time and create a lot of interest - at least for me. At last, I'm getting poultry. They can't be free-ranged - agreement with the farmer, and with the dogs - so it has to be a more complicated, creative system. They'll be near the house, on a slope which we don't use but which has several fruit trees (columbian sapote, araza, lime, pitanga), which will be incorporated into their larger run, and which should provide seasonal food, shade and shelter.

Construction won't start until beginning of May and the birds won't come until mid June, which gives plenty of time to establish the basics.

Firstly the coop and primary run must be absolutely secure - dogs, raccoons, pizotes, possums, olingas, snakes and hawks being my main concerns. The primary run will be completely wrapped in hardware cloth, ¼ inch - including a subterranean floor about a foot down. I'd love to use recycled plastic bottles or bamboo as the main building material, but I think I'll end up going for zinc panels for the extra security and longevity. The slope is about an 8 inch drop over 15 feet, and about 35 feet from the top of the ridge, so it shouldn't get too muddy. I'll cover it partially with a tarp, and the coop will have a zinc roof: it's been a really wet year.

Secondly food is a major concern: even though Talamanca has declared itself GMO free, pet and livestock food is basically GMO soybean and corn. I'd like a closed loop system as much as possible, with as little resorting to commercial feed as I can.

This means that I'll also be farming black soldier flies, duckweed and several forage species. I've started my bsf colony, or barracks, and a week into the project all is going well. The black soldier fly is native here, and for years the flies have been visiting me working in our workshop kitchen, maybe just one every other day or so. The farmer and Ana have always shoo-ed them out, saying that they bite. But they never bothered me, they look placid and I have always figured myself a bit of an Ancel Doolittle capable of living in harmony with them. Well it turns out that they don't have a functioning mouth or a digestive system, so they don't really bite. They do look a bit like chias, a sometimes aggressive wasp, and I think that's what troubled the farmer and Ana. I'm not so much a Doolittle as a I thought.

The pupae is an excellent source of protein (42%) and their nutritional breakdown looks an awful lot like the nutritional label on better quality chicken feed. There's a lot of information online about raising black soldier flies, (the photo comes from the excellent black soldier fly blog:  ) and I'm sure I'll be throwing in my experiences too. So far I have questions about humidity levels and I have an egg cluster that just hasn't hatched and I don't know why. But my bin is up and running and I'm about a week away, maybe, from harvesting the first batch. Very excited, like can't sleep excited. These first batches I'll be just growing out the flies to ensure I have a good supply and a few generations which know where the bin is. I'll have two bins: one down by the workshop, where we process all the fruit, and one up by the poultry house for composting the manure. The manure bin won't be harvested - at least not for the poultry.

The manure bin is an important aspect of my micro farm: I don't want the smell to attract any more predators or rodents, and it's quite near the house. The bsf deter houseflies and an active barracks should be able to deal with all the manure produced each day, plus it will get eaten so quickly that there will be little time for smells to develop. The waste produced by the bsf is, I understand, excellent food for worm bins, so hopefully I'll be able to incorporate those in the future.

For green feed we already have katuk and chaya up here. I've planted out some spinach and I'll be adding gandul, pumpkin and moringa. According to what I can find online, madera negra can be used for up to 4% of the diet. Yucca / cassava leaves have mixed reviews, as do taro leaves, Canna edulis is another option. Needs further research.

Duckweed we already deal with in the nursery and pond, so I'll be bringing some up here to 'farm'. Dry weight, it's between 25 and 45% protein depending on the nitrogen source and sunlight. Not sure yet whether it'll be fresh and free choice
or whether I'll have a separate system.

So, the name. The act of naming bestows a sense of reality and lends a permanence to things. My little micro farm needs a name. Hill, home and upper are all such common names but for that I like them as they seem rooted in tradition, and again, have a sense of permanency. Upper is too broad, as that's what we call everything that's not the lower farm. I like home farm - sounds cosy and may endear others to the project. I have other plans on closing various other loops, but all in good time :)