Fertilizer inquiry - Orchid Board

TheNewGuy · #1 03-28-2008, 02:33 AM

Hi everyone, I need some help here. I've read that orchids should be fed with a non urea fertilizer, however I don't understand why. Can someone help me out here?

I purchased some orchid specialized fertilizer that has a ratio of 19-31-17. Now from what I understand this fertilizer would help promote blooms more than growth, however, in the nitrogen, 13% of if is urea based. What's going on here????

kiki-do · #2 03-28-2008, 08:40 AM

I get confused also with the fertilizer.

I'm going to bump this back up to the top of the posts in hopes someone else will give you the information you are searching for. There are some great experts here on OB.

Ray · #3 03-28-2008, 08:49 AM

Plants cannot use nitrogen directly from urea. It must be decomposed to to release the nitrogen in ammonium or nitrate forms which the plants can use. Some feel that the decompositions comes about from soil-borne microorganisms, and since we don't grow orchids in soil, it's really just wasted.

IF you really want to learn more, read the "Primer on Plant Nutrition" here: Plant Nutrition

I also want to disillusion you about the "bloom boosting" of high phosphorus fertilizers. They don't.

Plants actually don't need a lot of phosphorus, so the extra is just unused. It has been shown that high nitrogen levels prevents blooming, so manufacturers dilute the nitrogen in the formulation by adding cheap phosphorus minerals.

Hedge · #4 03-28-2008, 09:16 AM

Hi I always thought that it was the K or potassium figure that had to be high to get flowers? I am new to orchids, only been keeping them for about two years , but this certainly works for cacti and succulents.

Can anyone clarify this point for orchids for me?

Thanks
Hedge

Royal · #5 03-28-2008, 10:34 AM

Hedge, Look up one post. Last two sentences.

Hedge · #6 03-28-2008, 03:19 PM

Not phosphorus P but potassium K

quiltergal · #7 03-28-2008, 04:32 PM

Phosphorus is what supposedly leads to more/better blooms. I concur with Ray that it's too high N that causes plants not to bloom. I've also used "bloom boosters" and noticed absolutely no difference in bloom time or size/number of blooms. I think it's a waste of money. Just my

.

TheNewGuy · #8 03-28-2008, 05:12 PM

Okay, so I guess I need to get some different firtilizer. What would you suggest, and where would I get it?

TheNewGuy · #9 03-30-2008, 02:56 AM

I'm bumping this back to the top so that people don't forget about me!!!

Ocelaris · #10 03-30-2008, 04:36 AM

I'll bite, The hot item that a lot of people are using is the MSU formula, which Ray sells, although respectfully he doesn't promote it at every turn which is nice.

Here's a story.

A salesman goes up to a lady and sells her some magic fertilizer; the directions say to apply it every day. She does, her plants grow spectacularly. One day she peels off the label and notices that she's been just watering her plants with... just water. Yup, nothing but water. Furious she sues the salesman. "But your plants have done fabulous!" Says the judge as he throws out the case. The moral of this story, is that it's not necessarily WHAT you put into your plants, as much that you DO put anything into them. Paying attention often is worth more than any fertilizer. It's not a magic bullet, but merely a foundation.

I've been using Ray's MSU fertilizer for 6 months, and it works. Others have used it much longer. I do have a LOT of roots, my Vandas phenomenally so... I can't say I've been without flowers on any plant yet, but in a year's time I'll know, but I seriously doubt I'm short on phosphorous as I've flowered a few vandas now, and most of my others are growing well, if not flowering yet.

Basically it's a 13/3/15 NPK ratio + trace elements, and you can buy 2 formulas which are balanced for your water; RO or well water. I don't think he makes a city water, since it varies so great from city to city... but if you have relatively soft water to start with, you should be all right with the well water formula which I believe has NO buffering capabilities, so it relies on your city's water in order to maintain pH. Maybe Ray can comment on that, as I'm thinking of switching from RO formula to well water, as I have such soft water here in NYC, 30-40ppm EC, which I would think would be similar to well water?

Best way is RO + RO formula... RO = Reverse Osmosis water... basically no minerals at all... the important part is getting regular nutrients to the plant.

There are urban legends in the plant world that phosphorous and red light stimulate flowering, fruiting etc... which are more or less false. In the same sense, they attribute nitrogen and blue light to vegetative growth; which is also false. Now neither of these are 100% false, but it makes an easy sale, and people grab that concept and run with it. There are some reasons which people distort to make the above mentioned urban legends sound plausible, but if you see anyone relying on any one truth, it's false.

Ray's formula is great, he contributes as you've seen, and supporting him supports a good cause, as I see it. On the other hand, just about any balanced fertilizer will do, just make sure that it is relatively generic with trace elements, not some whacky 0/5/90 or 3/50/3 formula...