Advice on Fertilizing?

[orchidlauren]

Thank you all so much,
So for summary this is what I have planned:
Fertilize using 1/4th solution 1-2 times a month based on temperature.
Water regularly every week or to when it gets too dry.
I was wondering if I could use 50:50 MiracleGro Mix & Spagnum moss? It’s quite dry here & I know they need quite a bit of humidity.

[Ray]

Originally Posted by orchidlauren

Thank you all so much,
So for summary this is what I have planned:
Fertilize using 1/4th solution 1-2 times a month based on temperature.
Water regularly every week or to when it gets too dry.
I was wondering if I could use 50:50 MiracleGro Mix & Spagnum moss? It’s quite dry here & I know they need quite a bit of humidity.

Not "1/4 solution" (I assume you mean the recommended strength on the label), but 1/4 teaspoon of that formula per gallon, applied weekly.

If, somewhere down the road, you buy a different formula, you should adjust your dosing accordingly. For example, if you were to use K-Lite, a 12-1-1 formula, then you'd use 8/12= 3/4 teaspoon per gallon, giving you approximately the same amount of nitrogen per gallon as 1/4 teaspoon of your current formula.

[orchidlauren]

Yeah sorry for the miswording, will do!

[SouthPark]

Originally Posted by SouthPark

I have orchids sitting outdoors in plastic pots (in lava rock media) that have never been manually fertilised --- they probably get natural fertiliser with bugs/insects etc in their pots. Those orchids required no maintainence for a few decades.... watered by automatic sprinkler along with the lawn and shrubs. These orchids are big and strong.... flowering every year. So - for my other orchids, fertilising once a month has been just fine.

Just quoting myself, as I thought that I should at least attach some photos of examples of some of my orchids that have never been manually fertilised. Never once manually fertilised for a few decades.

They are not watered by hand as well. These ones get their water either from rain, or from automatic lawn sprinkler (which waters the shrubs and the lawn grass) ---- not the small sprinklers --- but proper lawn sprinkler.

The fan leaf orchids are Angraecum eburneum. And the dendrobium is Dendrobium discolor. These two sorts of plants - once sunhardened - can handle a real beating from intense direct sun.

Also, hiding on the mid-right-hand-side of the Dendrobium discolor photo is a rather small size Dendrobium moschatum, which also gets its water from lawn sprinkler. No manually applied fertiliser is given to this one. The sprinkler wets its leaves and all. Everything dries out fairly quickly. Good air circulation.

In the photos, in general, the plants grew up all the same - and the roots just go everywhere, even onto the ground. The plants do not rot. Showed no signs of disease/fungal/bacterial activity.

For certain years (not every year), when there is a big spike in sun intensity - some leaves do get burned. But no problem.

The growing media for all of these orchids in the photos is lava rock ..... aka scoria ... (locally variety is known as quincan gravel, pronounced 'kwing-kun' gravel). The media has never been renewed (ie. never needed to take the plant out and put in new media). The media has never been flushed with water.

For my other orchids, where I do apply monthly fertiliser, I will occasionally flush the pots with water..... like once a year. This doesn't mean that other people should do once a year - because this all depends on how much fertiliser they use, and their growing media used, and growing method, watering method, watering schedule etc.

Also attached are relatively recent photos (2019) of flowers from those particular plants (that have never been manually fertilised - not even automatically fertilised - for a few decades). I have a feeling that insect activity inside the pot might provide some fertiliser to these orchids, and the roots had even grown long enough to touch the floor (ground) - which then possibly forms an extra source of 'natural' fertiliser intake.

[orchidlauren]

Wow! They’re very beautiful! Wish I could do that here!

[SouthPark]

Originally Posted by orchidlauren

Wow! They’re very beautiful! Wish I could do that here!

I wish that you could or can too! What I find quite excellent is that you and other very keen growers do remarkable work with growing your orchids with various encountered constraints. We can all learn from your shared experiences in this orchidboard forum.

[richardb]

Like Ray I fertilize at every watering. I use a combination of Peters commercial (not orchid) fertilizers according to season and adopt the regime of "weakly weekly" which gives excellent results.
I understand the need to dilute ordinary garden fertilizers to maybe 1/2 or 1/4 strength but have never understood why people do that with specific orchid fertilizers. Much research has gone into those special potions so surely the instructions on the bottle should be followed.

[Ray]

Originally Posted by richardb

I understand the need to dilute ordinary garden fertilizers to maybe 1/2 or 1/4 strength but have never understood why people do that with specific orchid fertilizers. Much research has gone into those special potions so surely the instructions on the bottle should be followed.

My logic for using very diluted fertilizer is because the plants have evolved receiving solutions (rain) of VERY low solids contents and electrical conductivity, very frequently, so it makes sense to follow that in cultivation.

The ingredients used in "orchid" fertilizers and general-purpose garden fertilizers are identical. About the only difference is the label. Don't forget, a fertilizer manufacturer's goal is to sell fertilizer, not help you grow better plants. The "research" that goes into designing a formula is "what did the customer ask for?" or "can we make a generic formula that will suffice for more of our customers?", as switching is costly in a manufacturing operation.

About the only formulas I'm familiar with that were backed by university research are Miracle Gro Mir-Acid by Dr. O. Wesley Davidson at Rutgers 70-80 years ago, those originated at Michigan State University about 15 years ago, and K-Lite, derived from an MSU formula by one of their researchers. All were designed "on paper", with the mineral ratios based upon research into the needs of plants with some orchid-related assumptions, and in all cases the evaluation was the same: "We tried it and it worked".

[Orchid Whisperer]

I think of fertilizer as more similar to."vitamin supplements" (if you are comparing human vs plant nutrition) rather than "food". The basic building blocks come from photosynthesis. Fertilizer components are available (in nature) to orchids in low doses, through rainfall and runoff from tree leaves, branches and trunks. We provide fertilizer (in low quantities) because plants grown in the home may not receive enough nutrients in the right proportions for optimal growth.

As long as you are providing a dilute fertilizer that provides N,P, and K, you are probably providing what orchids will need, assuming some trace elements are provided by your tap water. The advice used to be, provide fertilizer "weakly, weekly" but "weakly, monthly" is probably sufficient, "weakly" being something more dilute than the fertilizer package recommends (try 1/4 strength). If you want to go with really dilute fertilizer, you could fertilize more frequently.

Aliceinwl, the advice on urea N is based on old information. Orchids utilize urea N with no problems (there has been published research on this). That advice is based in part on the fact that long ago, urea fertilizers contained a substance called biuret, which can harm plants. With better manufacturing, biuret is no longer a problem.

[orchidlauren]

Sorry for the late reply, been busy.
I’d love to grow my orchids outdoors but unfortunately AZ’s got some extreme temperatures & crazy weather, absolutely love your orchids though! I’ll dilute the fertilizer and use it weekly instead just to see how that works, thank you for the advice! & thank you for letting me know about the Urea N. I still thought that orchids couldn’t process that properly. Along with having a similar formula to other general fertilizers, I thought they would definetly be different, I will definitely keep that noted. Another question, sorry, what medium would work for my Miltonia? I heard that Miltoniopsos and Miltonias have different care setups, wonderinf if that also included mediums & repotting. Would 50:50 MiracleGro coarse mix & Spagnum moss work? Feel free to lettimg me know anything I need to change or add to the medium, or also what you guy’s have used successfully! Thank you for the help