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Fertilizing Made Easy

For those that aren’t sure about when to fertilize, here is a simple timetable you can use to make it easy.  Since we all use different fertilizers and our soil components aren’t the same, I can’t tell you how much to feed but rather when to feed.  This schedule is specific to Central and Northern California.


This timetable is for trees that are in branch development mode.  Do not use this timetable for trunk growth or sick trees.  They fall into a different schedule.


Do not forget to THINK!  Instead of following this timetable because I said so, think about why you’re following this timetable and if you need to make adjustments for your own situation.  There will always be a time where we may have to deviate from the norm for short or long periods of time.


Japanese Black/Red Pines

March 1 - June 1      

To build strength in the tree so it can handle de-candling in the Summer.

August 1 - December 1

A break in fertilizing from June to August prevents overly aggressive Summer candle and needle growth.


High Mountain Pines

September 1 - December 1   

This is a technique to reduce excess candle and needle elongation.


Deciduous/Broad Leaf Evergreens

May 1 - December 1

We want to wait till the new Spring growth hardens off before feeding.  This will help in reducing long internodes in the branches.


All Other Bonsai

March 1 - December 1

Since we’re not too worried about long internodes in most our other Conifer Bonsai, we can simply fertilize these trees from the beginning of Spring to the beginning of Winter.

Fertilizing Made EVEN Easier

One of my clients asked me if I could come up with a schedule that would make fertilizing even easier and simple, especially in regards to a specific brand/type of fertilizer.  The following is an even easier way of fertilizing.


Use this technique for 1 year and depending how your bonsai grows, adjust for the following year.  If for some trees, the growth is too much, reduce the amount used per feeding.  If other trees aren't growing enough, increase the amount the following year. Remember, you all have brains and it's your responsibility to observe the tree's growth and make adjustments from year to year.  The ability to adjust your techniques year after year will make you a

Better Bonsai Artist!

Fertilizer to Use

Osmocote Plus 15-9-12, 6 months slow release is the product I recommend using.  I like this product because it also contains micronutrients that your Bonsai need that other fertilizers tend not to have. This is a slow release chemical fertilizer.

How Much Fertilizer to Use

1 to 1 and 1/2 Tablespoon per 10" x 10" of soil surface.

When to Apply

Japanese Black/Red Pines

March 1

August 1

High Mountain Pines

September 1


May 1

August 1

All Others Bonsai including Broad Leaf Evergreen

March 1

June 1

September 1

Again, start with this amount and schedule to see how everything grows in the first year. If you need to adjust the following year, start by changing the amount of fertilizer being used and stick with the schedule.

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