Best fertilizer for phalaenopsis?

[Orchid Whisperer]

Originally Posted by Plant Happy

One of the challenges of using the internet for research is the conflicting advice, which is why I really like coming to this board where I can benefit from everyone's experience. Plus, I love that I can see the location of posters (I need to find out how I can add my zone and place).

Beth, how could prewatering dilute fertilizer when the fertilizer comes after the water?

When I see your posts, I see Columbia, South Carolina and Zone 8a.

[Brooke]

Originally Posted by bil

If the fertiliser is too strong to be used without prewatering, then it is too strong to use at all.

The point was made on anther thread, that the velamen on the roots soaks up moisture very quickly, and only the first moisture is absorbed.

I've also seen the statement that only first moisture is absorbed but my common sense struggles with that concept.

If you put fertilizer water in a pot, the fertilizer moisture can be used until the pot is dry.

I always water a pot thoroughly with plain water and then add fertilizer water to the pot. If you only use fertilizer water then you are either using a ton of fert water or you are not thoroughly wetting the pot.

Brooke

[bil]

Originally Posted by Brooke

If you put fertilizer water in a pot, the fertilizer moisture can be used until the pot is dry.

Brooke

Spot on. However, if you are talking epiphytes, then the medium should be so open that it retains little moisture. Those roots need air, and if there isn't enough air passing thru the pot, the roots will die.

In any case, the fertiliser should be very weak, weak enough that all waterings contain fertiliser. That way, what moisture is retained, contains fertiliser.

[bethmarie]

Originally Posted by Plant Happy

Beth, how could prewatering dilute fertilizer when the fertilizer comes after the water?

Below is the info I was referencing from one of Ray's posts. It's in a thread labeled Food For Thought.
I don't know how to link to it so I just pasted it.
------------------------------

"If you think about orchid plants in nature, their water supplies are pure (rain, dew/fog), and the nutrition cascading out of the forest canopy is 1) very dilute - on the order of 15-25 ppm TDS - and 2) is only present for the first few seconds after a downpour begins, becoming essentially pure again almost immediately.

As an evolutionary adaptation, the velamen on the roots has the unique ability to become very rapidly saturated, and instantaneously trap and hold ionic species, so they won't be washed away by the continued rainfall.

Prewatering saturates the velamen, and any ions in the water supply will occupy the capture sites, both of which preclude the capture and uptake of any subsequent fertilizer application. Granted, if that fertilizer solution is concentrated enough, there will likely be some diffusion into the saturated velamen, but what the hell are we doing applying that strong of a fertilizer in the first place??? Not only is it wasteful, but it's bad for the plants and the environment, as the runoff ends up in the soil and water supply.

I believe a better approach - and one I've been employing for the last few years - is to start with a pure water supply, add a very small amount of fertilizer (I use 25 ppm N in RO), and use that solution at every watering - for me, about every other day in summer, a bit less in winter. I am seeing much better growth, better-looking plants with more growths, and fewer incidents of disease.

My fertilizer concentration is still 4x-5x what the plants would see in nature, but still a lot closer to what the plants have evolved to."

[Ray]

I am in my 4th year of that regimen, using K-Lite with monthly KelpMax and Garden Solution additions, and I'm still very happy with my plants' performance.


Ray Barkalow
firstrays.com

[Plant Happy]

Figured out how to include my zone and location, Orchid Whisperer but thanks for the feedback!

Thanks also to Beth, Ray, bil, and Brooke. Sorry to keep asking questions, but here goes:
1. Ray, if I understand the abbreviations correctly in your wonderful instructions, you advocate using low nitrogen fertilizer, right?
2. Would using a tiny bit of SuperThrive once a month with the orchid fertilizer be similar to the additives you're using? (SuperThrive now contains kelp).
3. I've read that liquid fertilizer should not be stored. Sounds terribly inconvenient.

At any rate, I certainly have not been fertilizing nearly often enough. Have I mentioned that I love this Board?

[Paphluvr]

Yes, rainwater is great for orchids (unless you live in a part of the country where rainwater ph is low). I used to remove the lowest elbow from the downspout after it had been raining for a while and caught the water in a galvanized washtub. I then pumped it into a holding tank I kept in the garage. The orchids loved it!

If your well water is not too hard it can be beneficial, too. It contains many of the trace elements that all plants need.

[Brooke]

Originally Posted by Ray

I am in my 4th year of that regimen, using K-Lite with monthly KelpMax and Garden Solution additions, and I'm still very happy with my plants' performance.


Ray Barkalow
firstrays.com

I am in my 10th year of using your original recommendation of 125 ppm of MSU for pure water with a monthly addition of kelp and a cal-mag product. I'm also still very happy with my plants performance. I attribute my success to growing orchids that get awarded to this combination.

Brooke

[Orchid Whisperer]

Brooke, how often do you use the 125 ppm MSU formulation? Is that 125 ppm of nitrogen?

[NYCorchidman]

Originally Posted by Subrosa

The main factor in deciding which is best is more about the media than the species being potted. Bark uses up a lot of nitrogen, so for a mix including a decent proportion of bark you would want the higher nitrogen "grow" formula. For a plant in a mix without bark or mounted, the more balanced "bloom" formula would be the choice.

I thought this has been debunked as well.

---------- Post added at 09:43 PM ---------- Previous post was at 09:39 PM ----------

Originally Posted by Brooke

I've also seen the statement that only first moisture is absorbed but my common sense struggles with that concept.

If you put fertilizer water in a pot, the fertilizer moisture can be used until the pot is dry.

I always water a pot thoroughly with plain water and then add fertilizer water to the pot. If you only use fertilizer water then you are either using a ton of fert water or you are not thoroughly wetting the pot.

Brooke

If you mean water absorbed by the roots in the very first few seconds or less by first moisture?
Then the answer is no!
The roots will continue on absorbing water for a long time. I do not know exactly how long, but I know this because when I soak my plant, the longer I leave them in the water, the more they plump up.

By the way, I water by soaking the pot in weak fertilizer solution everytime.