Aquaponics

What do you get when you cross a tank full of fish and a vegetable garden?

You get a very productive food producing system called Aquaponics!

Over the weekend I ducked down to my local nursery and ordered a Balcony Kit aquaponics setup. I wish I had the balcony to put it on, but the kit is small enough to fit comfortably in a small space. Measuring only 2.7m by 1.5m and 97cm  high there are three grow beds that have the capacity to feed three people consistently (both fish and veggies).

Aquaponics works on the theory of growing plants in an inert media such as expanded clay pebbles with an ebb and flow water system, as is done in an hydroponic setup. The similarities of the two systems end there. Where hydroponics requires the regular addition of nutrients to the water, aquaponics uses fish to create nutrients.

The system works by adding fish food to the water, the fish eat the food, their by products are pumped into grow beds where natural bacteria turn ammonia into nitrogen which plant roots suck up and grow prolifically. Nutrient free water is then drained back into the tank for the process to start again.

Not only do you get a supply of vegetables, but as the fish grow to plate size you can take them to the kitchen as well!

So why am I giving away growing most of my vegetables in dirt you ask? Living in a tropical environment there are many problems I have found when growing in dirt, I’ve had more than my fair share of fungus, mealy bugs, weeds, birds, ants, weeds etc to deter the most enthusiastic gardener from even trying to get their plot growing to any kind of respectable standard. Not to forget over watering, under watering, over fertilising, under fertilising, digging the soil, conditioning the soil… the list goes on!

Call me lazy, but given my hectic work schedule these days the time to spend in the vegetable garden is getting limited (especially in the cooler months with less daylight hours!). I’ve see aquaponics as a way of getting the best food home grown food for my family as I can with less time input, or working smarter instead of harder!

So you can only grow leafy greens in aquaponics?
Not at all, many forums such as AquaponicsHQ and BackyardAquaponics have members that have had great success with root vegetables such as Beetroot & Carrot. Other popular vegetables include Corn, Peas, Beans, Tomatoes, Cabbage, Chili, Capsicum, Lettuce, Broccoli, Cauliflower, Egg Plant, Celery, Strawberries… Murray from Aquaponics.net.au has even grown a PawPaw tree!

Added Nutrients:
As the system is almost closed, the fish food is the only main additive, there can be times where plants become stressed due to nutrient deficiencies. Iron, Magnesium and boron deficiencies can be common, especially when your plants are getting large. Cheelated Iron, Epsom salts and borax can all be added safely (in small quantities) to the water without detriment to the fish. To reduce the need for additional nutrients a high quality fish food with a full range of minerals should be used.

Pest control:
Unlike dirt gardening, where you can get away with a squirt of insecticide now and then, any form of pest control in an aquaponics system must be organic. Should you go through with a dose of insecticide there will be a tank of floating fish. White oil, chili and garlic sprays and diluted milk will be you new best friends.

The planting density in an Aquaponics setup can be fairly thick given the even spread of nutrients from the water. Reports from forums state that you can plant most things at around half to 1/3 of the spacings that are recommended for dirt gardening. This won’t apply to plants such as cabbage or possibly tomatoes which spread to a large size.

Right now, I’ve got the area measured up, some seedlings getting ready to transplant, and another week or so to wait till my kit turns up!

Nasturtiums – a flower and a food

No garden is complete without a Nasturtium plant growing somewhere, thats why I planted some the other day…

This fast growing annual originates from Peru and has fascinated gardeners with its long stemmed large green umbrella shaped leaves for many generations. For those who are getting their kids involved in gardening, the Nasturtium is a great plant to grow as the seeds are large enough for small hands to plant. They are also great for young children as they are completely edible!

nasturtiumExpect bright orange, red or yellow flowers, some with semi-double or double blooms. There are also some verrgiated foliage varieties that will add to the interest of the garden.

Prepare soil in a sunny position to be friable and free draining, Nasturtiums will handle most soil conditions but having too much nitrogen will give huge leaf growth at the expense of flowers. Plant them in the spring time for cool climates, or from spring to autumn in warmer climates (like mine!).

They need total darkness to germinate so plant them deep, at least 12mm down (that’s half an inch in the old measure), so they are completely covered.

Expect them to poke their heads out after two weeks, and get ready for flowers about 10 weeks after sowing (that’s eight weeks after they pop up). Enjoy their lush foliage and bright flowers!

Here are a couple of videos to get you excited about growing Nasturtiums

[youtube:http://www.youtube.com/watch?v=VPy2oMBVxZ8]

[youtube:http://www.youtube.com/watch?v=cC8Z0nKLTL0]

Top Dressing Lawn – Horse Poo

With the abundant supply of horse manure I have at my disposal there has been some creativity in alternative uses around the yard over the weekend.

Horse poo on lawnA trial of overseeding lawn and top dressing with horse manure in a slow growing area has began. The area is quite sandy and bare with only some boring weeds and a little couch grass growing. After a spray down with wetting agent, a generous dose of lawn seed was spread, two wheel barrows filled with lumpy horse manure were dumped and spread to cover an area of about 9 square meters.

Should I have had a garden mulcher on hand I would have run the entire ute load through and spread evenly across the lawn. Not to be easily deterred, a quick hit with a low blade on the lawn mower (no catcher) pulverised the hell out of it and spread it evenly across the area, nice.

A good water with the sprinkler and we’ll wait and see how it all grows!

I’m keen to hear the tips have you got to get an old lawn onto the path to a greener future.

Potato Tower: Update

Its been three weeks since the build stage of my potato tower!

Potato tower 2After removing a heap of weeds that popped their heads up early, the potatoes began to show through and have developed well. Keeping in line with the plan I’ve put down a layer of hay on top to cover them up so they will continue to push through and grow clean potatoes amongst the hay.

At the base there is a micro irrigation dripper that will deliver 4 litres per hour to the base of the plants, but I expect that over time I will need to add some water to the top to ensure the spuds grow to a good size. A good liquid fertiliser from time to time will also give the plant a much needed boost.

Here is an alternative to my Potato Tower that I found on YouTube.

[youtube:http://www.youtube.com/watch?v=t-0naLDO5yc]

Planting Day

Living in a tropical environment has its benefits such as lots of rain, plenty of warm weather and great lightning shows, the best of all is the great weather during the ‘Dry Season’ or winter as it is more commonly known in all other parts of Australia.

Being a long weekend the garden has had a lot more attention than usual with weeding, pruning, composting and most exciting of all planting. While at the nursery on Friday the wife picked up a punnet of Snapdragons and a punnet of Seaside Daisy.

Seaside Daisy is pretty drought hardy once established and is a fantastic ground cover which only requires 3 to 4 plants per square meter to get great coverage. It produces the prettiest little daisy heads which are around 10mm in diameter.

I’ve never grown Snapdragons before, but my wife assures me that they are quite pretty and will grow quickly and to around 80cm in height.

The seed bin got rummaged through again and following were direct seeded into growing location Cornflowers, Cosmos, Gypsophila, Nasturtium, Spring Onion and Kohl Rabi.

On the pruning front the blue salvias got a big hair cut, all of the old wood was removed to allow the young growth coming from around the ground to get some sunlight.Seeds

All the prunings and weeds will be thrown into the compost tumbler for a bit of spinning action. Speaking of compost, all of the seeds and seedlings were planted with a good dose of the compost from the compost tumbler.

Compost Tumbler Update

It’s been 14 days since I filled my Tumbleweed Compost Tumbler with grass clippings and horse manure. With a tumble or two each day the contents became very hot (too hot to touch one day) and has turned to a nice earthy brown colour with a sweet smell. The heat generated in the bin will be enough to sterilise any weed seeds that get put in, so there is no limit to what you compost!

Compost

Turning the bin can be a bit of a challenge when it’s completely full, but as the days go by the volume reduces due to the decomposing material. After the 14 days there appears to be a ~50% reduction in volume, leaving me with 110 liters of great compost.

My next challenge will be finding enough material in the yard to fill the bin every two weeks. There is already a stockpile of brown material such as leaves and old lawn clippings to add to the bin along with kitchen scraps and horse manure, but the continued supply may be an issue.

Over the next couple of months I will experiment with different materials in the bin and see how they compost.