self sufficient life

Breeding birds in our garden

Our garden is swarming with life. We hear little birds all day from all directions. Most bird nests are well hidden in tall trees or dense shrubs, but if you provide the birds with a suitable nesting location you can place it somewhere where you can watch the little ones grow up and fly out. We got a pair of great tits in our birdhouse and after seeing the parent birds fly on and off with food for the little ones for a while, they where ready to spread their wings today. We watched 6 little birds come out of the birdhouse and fly away into the big world.

Square Foot Gardening

Our kids are never playing in the sandbox because of the bugs and spiders that get in there, so today we got the sand out to try something new. Since the contents of our compost bin wasn’t ready to use yet, we went into the forest to get some good compost. We filled the sandbox with it and used some rope to partition the square meter box into 9 square feet patches.

Each square has been planted with a different crop. We have planted: four heads of lettuce, one tomato plant, one cucumber plant, four cloves of garlic, some rosemary, thyme, a sunflower and two patches with some different flowers.

The size of one square meter is perfect for our 8 year old daughter to walk around and be able to reach every part of her garden. This system was taken from the book All New Square Foot Gardening by Mel Bartholomew and it supposedly lets you grow about twice as much in half the space compared to traditional gardening, while only requiring about 20% of the work.

Fishy Tomatoes

After a bit more tweaking, the barrelponics system is up and running! I have put seven little goldfish in that I had rescued from our 800 liter goldfish tank before the big ones could eat them. The little ones overwintered in our tropical aquarium but where now getting big enough to eat the guppy fry, so they needed a new home anyway.

I have taken one of the tomato plants that I had planted in the garden a few weeks ago and moved it into the aquaponics barrel. Another one that is almost exactly the same size will stay in the soil. This should be a nice test to compare how the two plants develop and how much fruit they produce, let the waiting game begin!

Free food production in your backyard

Summer is really starting now! The last couple of days we’ve had 23 – 25C temperatures and the forecast for the next week is the same. While our friends from down-under are getting ready for winter, we can start growing all sorts of yummy things in the garden.

I thought I’ll use the long weekend to set up a little half barrel aquaponics system. I still had one of those blue barrels laying around, so I went ahead and cut it in half to create two grow beds. After filling the grow beds with washed gravel and filling them with water the troubles started: I was using a loop siphon to do the ebb and flow in the barrel, but the loop just didn’t work like it should. When filling the barrel, the siphon should kick in at a set level and empty the barrel again, giving the plant roots access to oxygen rich air. After the barrel has been emptied the siphon should break and the barrel should slowly fill up with water again.

My siphon either wouldn’t kick in correctly, leaving the barrel flooded, or it wouldn’t break, leaving the barrel empty at all times. Some more tweaking is necessary for my barrelponics to work. Since I don’t have to go to work today, I’ll have all day to try to get this working.

Aeroponics barrel

The weather was beautiful yesterday, so I decided to go outside and make a new hydroponics system. Well, actually its an aeroponics system, because the plants roots will not be growing in water, but they will be hanging down from the mesh pots and misted with a nutrient solution. This method of growing gives the roots better access to oxygen, which has a positive effect on the plant growth.

I didn’t want to go out and buy anything, so I went looking for usable items in the garage and basement. I found a rainwater barrel, that I wasn’t really using. I cut the barrel in half, because it was too big. One rainwater barrel lid has been glued to the bottom of the half that I cut of. Another lid is used to hold the plants.

I bought some microdrip system parts, by Gardena, a while ago. Their system uses flexible tubing and they have a whole range of different drippers and spray nozzles that are installed into the tubing simply by screwing them in. Since I had these parts laying around, I used them for my aeroponics barrel. You can see the black Gardena tubing in the picture.

I made 8, evenly spaced, holes in the top lid to hold the mesh pots for the plants. The tubing is glued to the inside of the lid with some hot glue. A spray nozzle is installed in the tubing right beside each mesh pot, so each plant will have access to the nutrients.
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Here’s a close-up of one of the mesh pots and a spray nozzle. (You can click on the pictures for a bigger view)

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With all of the mesh pots installed the top of the lid looks nice and clean. The hole in the middle is used for the pump to suck the water out of the barrel. I’m using an external aquarium filter pump, but if you would use a submersible pump the whole thing would look even cleaner, with only one power cord coming out of the barrel, instead of two pieces of garden hose. Like I said: I’m only using parts that I had laying around and the external aquarium pump was what I had to work with and it does the job!

With everything hooked up the spray nozzles started spraying a fine mist of water drops onto the mesh pots. Looks like my aeroponics system is working nicely! I’ve planted some seeds in a germination tray. When they get big enough I will put them into the aeroponics system and then we’ll see if it really works as good as others say!

The lettuce raft

I build a small raft system a while ago and plumbed it into my bedroom aquarium. It didn’t turn out to work too good however. Tomato and lettuce seeds started sprouting after only a few days and seemed to grow quite nicely, but as they got bigger the growing stopped and the plants where looking terrible! I finally found out what’s wrong with my plants: the T5 compact fluorescent lamp I had installed for the plants was not delivering the light that the plants need. The spectrum of my lamp is about as bad as it gets for plants, so I need to find some better lights to start growing lettuce inside.

Since the weather conditions are starting to get better for outside growing, I’m going to build a new system for outside use and upgrade the lighting on my small raft system when the weather gets colder again.

Small scale aquaponics setup

The nice thing about aquaponics is that it is very scalable and can be set up almost anywhere. If you want to try out aquaponics you can set up a small system to grow herbs in your home. All you need is a small fish tank and a container that can be used as a grow bed. The fish in the tank will fertilize the water with their excrements and the growing plants use these nutrients to grow while cleaning the water.

In a small setup you can locate the grow bed above the fish tank. The grow bed can be filled with lightweight expanded clay aggregate or gravel. A water pump on a timer will fill the grow bed with water and small holes in the bottom of the grow bed let the water flow back into the aquarium. The holes have to be sized to let less water pass through them than the pump delivers to the grow bed. This way the grow bed will fill up while the pump is running. Once the pump shuts off, the grow bed will empty out into the aquarium.

A system like this is called flood and drain and makes the plants grow nicely. In the flood stage the plant can take up water and nutrients and in the drain stage the plants roots have access to oxygen. You can place your setup by a window or, if you don’t have a suitable spot that receives enough light, you can add some lights.

(sketchup model by: Dave)

Aquaponics

My aquariums have a healthy balance of fish and plants. The water is crystal clear and the plants are thriving. I don’t have to do any water changes to keep all levels in the optimum range, the only thing I have to do is top up the water every other week to compensate for evaporation. A well balanced system like this is easy to create and maintain in an aquarium. It takes some experimenting, but once you get the hang of it the maintenance is next to nothing and you can just sit back and enjoy watching the fish.

Intensive fish farming is a different ball game. If you want to make a profit you have to put a lot more fish in your water. The water gets polluted by the excrements produced by the fish, making the water toxic for them. Bacteria that live in a biological filter can convert the highly toxic ammonia into nitrite and nitrite into nitrate. High concentrations of nitrate are still bad for your fish, but they are an excellent nutrition for plants!

You could use the nitrate rich water to fertilize the soil in your vegetable garden and replenish the fish tank with clean water. This would however require a lot of fresh water and a big part of the nitrates would sink deep into the soil, beyond the reach of your plants roots.

The solution here would be hydroponics. In a hydroponics system you grow plants in water instead of soil. The water in a hydroponics setup is enriched with nutrients that the plant roots normally extract from the earth. Small crops like salad and herbs can be grown on a raft that floats on the water and has holes in it for the roots to reach the nutrient rich water. Bigger crops like tomato plants need some coarse gravel or rock wool for support. This grow medium is located in a tub that is flooded with the nutrient enriched water. After the growing plants have extracted the nutrients from the water it has to be enriched again.

Hook the fish farm up to the hydroponics and you have an aquaponics system. The fish provide fertilizer for the plants and the plants clean the water for the fish. The balance in an aquaponics system is much like in my aquariums but both the fish and plant density are much higher. As long as you make sure that this balance is maintained, you can make the aquaponics system as big or as small as you want, ranging from one small fish and one plant to a pond with thousands of fish and an acre sized greenhouse.

A big commercial system isn’t for everyone, but you can have a small aquaponics system in your garden or kitchen made out of items you probably already have laying in your garage or shed. Put a little work into it and you can enjoy home grown fresh herbs and vegetables, without the pesticides!

Looking for information on the subject, I stumbled upon the Backyard Aquaponics Forum, which turned out to be a very friendly community of people with a great deal of knowledge and experience in this field.

How much land can feed a family?

After reading about people using several acres of land to be self-sufficient I started wondering how practical it would be where we live. A little more research on the subject lead me to a great article by Greenspree, which takes a detailed look at how much food a family needs and the yields per acre for different types of crops.

The bottom line of the article is that about a quarter of an acre, which is roughly 1000 square meters, can provide most of the vegetable needs for a family of four. Agric says that only about half of that area is needed to be self-sufficient, which sounds realistic, because you can plant different crops on the same patch of land at different times of the year.

The Crop Yield Verification sheet used for the calculations by Greenspree contains a big list of different fruits and vegetables that you can grow and their yield per acre. What I found interesting is the relatively high yield of apples and pears and when planted in the middle of a nice patch of grass where the kids can play, they don’t take up any of the space of your vegetable garden. The only problem with fruit trees is that they need quite a few years of growing before they produce food, so these should not be taken into account when figuring out what we can grow.

I have put 1000 square meters for growing crops on my list of requirements. This should be able to provide my family year round with vegetables and leave some extras that can be sold on the farmers market to bring in some cash to buy things that are not practical to grow on a small scale.