Feeding Your Bonsai

Fertilizer and Feeding

If you were to ask a dozen Bonsai Enthusiasts “What is a good fertiliser for Bonsai?” you would get a dozen different answers.  The range of fertilisers on the market is staggering but they all contain just three basic elements in various amounts plus a few trace elements.

Somewhere on the packet you will find the N.P.K. breakdown.  This gives you of the following three essential nutrients:

“N”Stands for Nitrogen, which is mainly responsible for stem and leaf growth and gives them a good healthy colour.

“P”Stands for Phosphorus, which builds sturdy trunks and roots.  It also greatly enhances the trees resistance to diseases.

“K”Stands for Potassium (from the Latin ‘Kalium’), which is the main flower-inducing nutrient.  It also helps strengthen young shoots and roots for the Winter.

Trace Elements

Trace elements are vital for healthy trees but are only required in tiny amounts.  Read the label carefully to make sure that the fertiliser contains some of the six major trace elements.


Always follow the instruction on the packet as to much food can burn the roots.  It doesn’t matter weather the N.P.K. numbers are high (24:20:20) or low (3:4:4) the manufacturers will have allowed for this in the dilution rate.

Liquid fertilisers can be watered on to your trees or you can submerge them in the mixture until the soil is saturated.  The major advantage in liquid feeds is that you can control when and how much is given.

Pellet fertiliser are probably the better choice as they only need to be applied once or twice a year and you wash the feed into the soil when you water, not out as with a liquid feed.

If you have a small collection of Bonsai houseplant fertilisers are generally fine.


Begin feeding in the Spring when signs of new growth start to appear.  Perhaps a mild feed of Fish Emulsion for the first feed followed by a high Nitrogen feed. By the Summer reduce the amount of Nitrogen in the feed and opt for a more balanced fertiliser.  In the Autumn use Nitrogen free feed if possible.  This will help harden off the roots and new shoots for the colder months.  Do not feed during the Winter months as the tree is dormant.  Do not feed a tree if it looks unhealthy.  You may just be aggravating an existing problem.  If all this is a bit complicated the safe option is to feed with a balanced fertiliser during the growing season.  You may not get the same results but you can be sure your trees are getting a bit of everything they need.

The following is a Table showing the N.P.K. breakdown of some popular fertilisers.  Please feel free to add any others to the list to use as a reference.

High Nitrogen Chempak “2” 25 15 15
Chempak “Orchid” 35 10 10
Miracid 30 10 10
Fish Emulsion (Mild) 5 2 2
High Phosphates Miracle Grow 15 30 15
Chempak “Var. Foliage” 5 50 20
Chempak “Green Foliage” 20 30 10
Chempak “African Violet” 12 36 14
High Potash Chempak “4” 15 15 30
Phostrogen 10 10 27
Tomorite 4 4 8
Chempak “Flower & Fruit” 15 15 25
Low Nitrogen Chempak “8” 12 25 25
Chempak “0 10 10” 0 10 10
Chempak “Cactus” 8 34 32
Balanced Chempak “3” 20 20 20
Liquid Growmore 7 7 7
Phostrogen (Acid Plants) 15 10 15
Green Dream 6 6 6

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