If you want to steer clear of synthetic chemical fertilisers, there are some new natural liquid fertilizers, on the market, that will do the trick for your organic growing needs, especially for those of you, who grow using hydroponics or aquaponics. But for those pioneering spirits among you who want to save money, here are some tips for making your own liquid fertilisers.

The following is a recipe for making manure tea. This recipe was intended for traditional potted plants, not for hydroponics, so we’ll have to make adjustments to it for hydroponic or aquaponic use. This recipe is just to get us started. And I don’t recommend that you mix this recipe up in your apartment, unless you want to annoy your neighbours.

Manure Tea

Materials for a small amount: bucket with tight lid, cloth or burlap bag, 1.5 kg fresh cow manure, water, twine.

Materials for a large amount: large plastic garbage bin, cloth or burlap bag, 4 kg fresh cow manure, water, twine.

NOTE: You can also substitute horse, rabbit, chicken or sheep manure for the cow manure, or mix them in. Don’t use dog or cat manure, which contain pathogens and may spread diseases.

Put the manure in the bag and then tie the bag and put it in the bucket or can. Fill the container 2/3 of the way with water. Steep this for four days, occasionally lifting, poking or stirring the bag. By this time the tea should be light brown and ready to use. You can dip the tea out as needed, replacing it with new water and re-stirring the bag. You can reuse this manure for about a month before replacing it.

If you’re using this tea for a soil-based garden, you should dilute it to one-third strength for weekly use. If it’s for potted plants, dilute it to one-tenth strength for weekly use.

Manure tea is a good all-purpose fertiliser, having small amounts of nitrogen, potassium, and phosphorous, as well as a fairly complete range of trace minerals. But for hydroponics, you’ll probably want to adjust the solution for various types of plants, using various additives. And for daily use you’ll need to dilute it further. And remember, manure and all the materials below may vary in strength from batch to batch, so be careful when applying.

Additives

Compost is usually more nutritionally complete and less harsh than manure, and it’s neutral in pH. You can substitute compost for the manure or add it to the mix. Compost is weaker than manure, and probably won’t need to be diluted.

Wood ashes are very high in potassium, unless they’ve been left out in the rain, in which case the potassium may have already leached out. They are also highly alkaline, so they can help adjust your pH balance. Since ashes cake up, they should be thoroughly mixed in with the manure or compost.

Bat guano is very high in phosphorous and nitrogen. Due to its high cost, you might want to make a separate tea with it and save it for occasional use on flowering plants that need a lot of phosphorous.

The following ingredients are probably too expensive to add to the tea mix until after the tea is taken from the bucket or can. You can use them to adjust the final mix.

Liquid seaweed is fairly high in nitrogen and potassium, and has a full range of trace elements.

Fish emulsion is high in nitrogen and contains some phosphorous, potassium and trace elements.

Dried blood is very high in nitrogen.

You can experiment with using powdered fertilisers in the tea bag, but most of these probably won’t leach through the bag very well if at all.

If you can’t get the right solution for your needs, you can always buy some pre-made liquid fertilisers to add to your mix to perfect it.

Happy experimenting.

(This is an article from within the second edition of the Backyard Farming Magazine. The complete magazine is available as an electronic download by clicking here.)