Fertiliser... Needing some clarification

[Kenji B]

Hi guys,

So I am new to feeding plants. Done a little research and bought a couple of products. Have a couple of questions about a couple of things.

When I have read bonsai forums and have seen people talking about feeding with say, a balanced fert 20-20-20, I understand this is about the Nitrogen, Phosphorus and Potassium levels found in them. Problem is I cannot find any with this percentage. I think maybe I am misunderstanding the 20-20-20 part? The liquid feed is Yates Nitrosol original which is a blood and bone fertilizer with an N.P.K of 8.3.6 and the slow release pellets N.P.K is 19-3.75-11 At first for some reason I thought a high N level is more important than P and K. K being unwanted because my trees dont need to flower or fruit. I now feel like P seems the most important or should be more level with N since root and shoot growth will be desirable at my very early stage of bonsai enthusiasm (keen to grow some trunks!). Why does it seem to be a trend to find fertilizers with lower P values?

I have fed my plants twice so far and they seem to respond well. The reason I got onto it was one starter I bought looked like it had some deficiencies and was dying. after repotting in zeolite and pine bark and fertilizing it is now doing really well. With my small but growing collection I am making the move to having a more "modern" substrate which will have little to no nutrients so I am wanting to know the most about my fertilizing needs!

Any help will be appreciated!

[shibui]

One of the problems with fertilizer ratios is that in the US they measure the elements differently so the equivalent of a US 20-20-20 has different numbers here in Aust. Unfortunately I cannot find the conversion so can't give an Aust equivalent but you could contact any of the fert companies and ask.

The other issue is that plants rarely need equal amounts of all 3 macro nutrients. They usually need less P and K compared to N but all plants do need some of each all the time. Fortunately plants can pick what they need and let the rest go past the roots.
K is needed for healthy growth it is just needed in higher amounts for flowering and fruit.
P is important for root growth but is needed in smaller amounts than N hence the generally lower P ratios.

To grow trunks quickly you need to grow plenty of leaves and shoots so try a high N fert but with some P and K and trace elements because all are needed for healthy growth.

[DustyRusty]

Kenji. Don't stress. The ones you bought will be fine. Balanced is good yes but you have something of all three so your plants have access to everything they need.

A couple of things: its cold in NZ. Your plants won't need a whe lot of fert until spring. Your deciduous trees won't need anything until spring. You've just switched to a substrate style mix. Make sure you feed more often than the packet tells you to (during growth). Hope this helps!

[kcpoole]

Hi Kenji

I probably fertilise too little, and have pretty much stopped for the year. My pines and junipers will get fert again this winter, but only liquids.

Pup probably sums it up best when he says. (to paraphrase him). It does not matter what you use, use something. ie Grab any fertiliser lying around our is available and use it.

Ken

[Kenji B]

Thanks guys! That puts my overthinking mind at ease, knowledge is king though but in this case the knowledge that anything will do is good! I am playing around with tropical plants in an indoor grow box set up so this post was mostly about feeding them. Thanks again