Osmocote extended release fertiliser granules

[orchidsarefun]

This scientific study from 2000 has tables that show the release timeline.
https://theses.lib.vt.edu/theses/ava...ricted/etd.pdf
I would assume that the release coating technology has been considerably improved since then.
We know that plants ( whether orchids or not ) only utilise fertiliser at specific times and the trick is to supply it in optimum quantities at those times. I would posit that slow release granular fertiliser is best suited to do this as it's always there, as opposed to weakly weekly or once a month or whatever. This would be more so if exposed to rain as well - as mine are. More benefits to orchids like Catasetum and lycastes that feed heavily too. Its fairly easy to see if the granules are "empty" too. They change colour and become transparent. Top up time. I noticed this last year with dynamite granules. The Osmocote this year still looks ok, it's only been about 2
months.
Of course this type of application wouldn't be good enough for the ppm measurement people.

[Ray]

I've known a few growers who incorporate it into the medium at repotting, yet still use water soluble fertilizer....

Once again, we see that "different strokes for different folks" is universally applicable to orchid growing!

[Dusty Ol' Man]

Bumping up this old thread with a new question. If Osmocote is crushed, will it then be soluble in water? If so, then the question would be how much per gallon?

[WaterWitchin]

I'm sure no fertilizer expert, but why would you crush it up? It's intended as a slow release fertilizer. If you want water soluble, just use water soluble.

[Dusty Ol' Man]

Originally Posted by WaterWitchin

I'm sure no fertilizer expert, but why would you crush it up? It's intended as a slow release fertilizer. If you want water soluble, just use water soluble.

I don't have any balanced water soluble and for the life of me can't seem to find any anywhere. I will order some online but wanted to use something in the meantime. Poor vanda just isn't doing well.

[Ray]

The formula of a slow-release fertilizer is expressed in the same weight percentages as powdered fertilizer.

[WaterWitchin]

Order some KLite from Bill and getter done. Firstrays.com

[SouthPark]

It's a choice for sure. If it doesn't create any issues, and consistently works well for particular growers for very long times, then I say stick with it.

I have lots of osmocote too - but I only use it for my regular garden plants and pot plants.

For my own orchids ----- I prefer once-a-month application of weak fertliser on the first day of each month (and mag-cal at 2 weeks into each month).

Manual control for fertiliser and mag-cal has worked really well for me for very long times.

[Dusty Ol' Man]

Originally Posted by WaterWitchin

Order some KLite from Bill and getter done. Firstrays.com

That's the plan, and some Kelpmax, too. Just waiting on the funds. I have a light to order also.

And thanks Ray, for your expertise. I always enjoy learning about the inner workings of the hobby.

[Mr.Fakename]

Originally Posted by WaterWitchin

and getter done.

A redneck term used to prod a fellow to complete a task; i.e. finish a beer.
Get 'er done, boy! Finish that natty!

Thanks for improving my lexicon WW.