Osmocote plus

[literatipenjing]

I’m thinking about using Osmocote Plus for fertilizing all my bonsai and pre-bonsai, mainly for simplicity in its application. My plan is to apply it once per year in the spring. Would appreciate comments on this from experienced users. Thank you in advance for all responses.

 

[Shibui]

I use another brand but similar product and find it good for bonsai. I still apply semi-regular supplementary fertilizer but the controlled release prills make sure the trees get nutrients even when I forget.
It's likely someone will mention the old nutrient dump but that seems to be something left from the really early days of first generation controlled release fert. Coatings have improved out of sight with many subsequent advances.
It is recommended that controlled release should be placed in the soil for maximum effectiveness. Sprinkling on the surface is the least effective way to apply. For the trees I have not repotted I drill small holes in the soil and pour the required amount into the holes then cover over.

 

[BrianBay9]

I also use it in combination with regular liquid fertilizers. I think you'll find you want to apply it more than once a year though.

 

[Shibui]

I think you'll find you want to apply it more than once a year though.

Won't that depend on the release rate of the product?
Osmocote (and most of the competitors) make a whole range of product with different nutrient levels, different release times from 6 months through to 18 months and different timing for the release - lo start or hi start.
I was using the 18 month lo start formulation but that's hard to get here now so I've swapped to an alternative company's 12 month release product which should continue to release nutrients for a full 12 months.
I guess most of the nutrients released in winter will be wasted so maybe a 6 month release product applied each spring might be better for deciduous trees.

 

[penumbra]

I use it in all my pre bonsai and other plants I am growing on. It is made a huge difference in the health and growth of my plants. I use the 6 month formula with micro nutrients.
I also foliar feed fairly frequently, but this requires forethought and more effort. I alternate between Miracle Grow and Neptune's Harvest about every other week.
I can't really add to what has been stated in prior posts about Osmocote but just wanted to confirm that I am very happy using it and that I never had a problem with it even 20-30 years ago.

 

[BrianBay9]

Won't that depend on the release rate of the product?
Osmocote (and most of the competitors) make a whole range of product with different nutrient levels, different release times from 6 months through to 18 months and different timing for the release - lo start or hi start.
I was using the 18 month lo start formulation but that's hard to get here now so I've swapped to an alternative company's 12 month release product which should continue to release nutrients for a full 12 months.
I guess most of the nutrients released in winter will be wasted so maybe a 6 month release product applied each spring might be better for deciduous trees.

All I've seen locally is the 6 month product. Didn't know they had a longer one!

 

[penumbra]

All I've seen locally is the 6 month product. Didn't know they had a longer one!

They actually make around 20 different fertilizers that are all based upon their polymer coated time release process. Think about it, if you are growing annual plants you only need a 90 day fertilizer, at least in my climate. They make fertilizer both with and without micros. They make slow start formulas and some that feed heavily and some not so much. They even make a formula that has aluminum sulfate for acidifying.
As to where you can find these formulas, I don't know. I have seen maybe 4 or 5 formulas.

 

[literatipenjing]

I use it in all my pre bonsai and other plants I am growing on. It is made a huge difference in the health and growth of my plants. I use the 6 month formula with micro nutrients.
I also foliar feed fairly frequently, but this requires forethought and more effort. I alternate between Miracle Grow and Neptune's Harvest about every other week.
I can't really add to what has been stated in prior posts about Osmocote but just wanted to confirm that I am very happy using it and that I never had a problem with it even 20-30 years ago.

Penumbra, thank you. Your report sounds very good and also it confirms my planned approach to feeding my trees. Our growing season in Victoria, BC is about 7 months for deciduous and a bit longer for conifers. Osmocote Plus should cover that period.

 

[Shibui]

As to where you can find these formulas, I don't know. I have seen maybe 4 or 5 formulas.

It's the same here. Only a couple of products available at general retailers because the market is not huge. I go to a horticultural specialist supplier for the less common formulations and purchase in 20kg bags to get one that suits my needs.
I've just been trying to find a full list of Osmocote controlled release products but it does not seem to be very easy. This is the best I can find at short notice - https://icl-sf.com/au-en/explore/nu...ing-plants/controlled-release-fertilizers-oh/ Each category listed on that page has a number of different formulations nested within.

 

[penumbra]

I am particularly interested in the Osmocote Exact Mini with micros for starter plants. It is a real shame these products are not more available.

 

[BrierPatch]

I was planning on using the Osmocote Plus too for all my pre-bonsai (which is about all I have). Thanks for all the info!

 

[hemmy]

Would appreciate comments on this from experienced users.

I’ve used the Plus mixed in with the substrate on pre-bonsai for several years with no issue. However in my cooler coastal climate I was warned about using it by other growers that either had negative experiences or were relaying 2nd hand info (it was never clear). The story goes that plants were killed by over fertilizing when adding new to old fertilizer that was not exhausted because the old coating had not broken down at cooler temps. When temps spiked, it all released and burnt.

I have my doubts on the accuracy of this anecdotal info. But I present it because in your cooler climate you will see an increased longevity and slower release based on the cooler temps. Here’s a link to paper with good charts.

https://greenhouse.hosted.uark.edu/Unit08/images/H5124_spec.pdf

 

[Deep Sea Diver]

Gosh, I spent a couple hours on this last year and found the answer was it depends on the formulation, here’s a bit more descriptive link I posted last fall again.

We use Osmocote Plus in tea bags here….. also put other granular fertilizers in tea bags too for trees we don’t use Osmocote Plus on 1/2 strength. Then add fish emulsion, CalMag, and Humic acid etc every two weeks , except for azaleas…. MiracleGro//Humic acid is the supplemental liquid there.

The tea bag idea I shamelessly stole from where I volunteer and also @Leo in N E Illinois!

Granted, tea bags are a bit of a pain, but they allow more control and less prills in the media.

cheers
DSD sends

 

[ghues]

I’m thinking about using Osmocote Plus for fertilizing all my bonsai and pre-bonsai, mainly for simplicity in its application. My plan is to apply it once per year in the spring. Would appreciate comments on this from experienced users. Thank you in advance for all responses.

Hello from up Island. Used it for trees in development with really good results. The prills are temperature and moisture sensitive so effects will differ from place to place. Going with organics for more refined trees.