Thoughts on fertilizer.

[Team Ferret]

Everyone, thank you for posting to this thread. Ross really had me rethinking this topic. So, here is what I have learned from this thread (please correct me if I have misunderstood);

It is clearly understood that orchids don’t need more phosphorous.

That 125ppm is not a high concentration of fertilizer. This understanding is in spite of book and online recommendations of ¼ to ½ strength fertilizer solution which would be 30 to 50 ppm.

Based on the presented abstract of scientific research, the use of higher concentrations (250 to 500ppm) won’t hurt the orchid, and if grown in southern latitudes nearer the equator would actually benefit the orchid.

Mineral salts from the fertilizer rarely if ever build up on the roots, even in bare root culture.

Feeding is not as big of an issue as I was understanding, or misunderstanding.

My conclusion is that I should feed my orchids how I feel is best and if I am not happy with the rate of growth I can increase the fertilizer to a reasonable rate (I am assuming up to 250ppm here in FL). Although not mentioned, I do understand that the amount of fert is only part of the equation. Light, humidity, air movement and overall plant health must support the target growth rate.

I know I should chill a bit about growing orchids. Its supposed to be a hobby for me, you know something to help me RELAX. I have worked with metal and mechanical stuff my whole life and can’t tolerate mistake or failure. Most of the time with metal you get a second chance to get it right, but with living things you don’t. So I am breaking my head trying to get this growing stuff right. What I forget is that plants are alive and can take care of themselves, given that they have the basics.

Once again, thank you for this discussion.

Dave

[Ross]

Originally Posted by Team Ferret

That 125ppm is not a high concentration of fertilizer. This understanding is in spite of book and online recommendations of ¼ to ½ strength fertilizer solution which would be 30 to 50 ppm.

Dave, sort of. I think what several of us said is yes 125ppm is not a high concentration but it might NOT be up to snuff for certain 'chids like some of the Phals. But it's a good compromise when one doesn't have the time or patience (like me) to adjust mix for a varied collection. In other words, it's "good enough" to get the job done. Works for me so far.

Originally Posted by Team Ferret

Feeding is not as big of an issue as I was understanding, or misunderstanding.

My conclusion is that I should feed my orchids how I feel is best and if I am not happy with the rate of growth I can increase the fertilizer to a reasonable rate (I am assuming up to 250ppm here in FL). Although not mentioned, I do understand that the amount of fert is only part of the equation. Light, humidity, air movement and overall plant health must support the target growth rate.

I think I agree. I pretty much went with the MSU recommendations since Michigan State is here in Michigan (and has a great football team this year, thanks for asking!) As for higher concentrations, I guess I'd want to know why I was doing that before I just assumed anything. You may be right.

I definitely agree on the other factors. I've made two major changes over the last year or so. I've gone to a steady feeding regime. Plants get fertilizer with every watering. Some every day, other as long apart as 3-4 days or a week. But each one gets totally submersed, totally flushed, whatever, depending on the container or mount.

Not sure what you mean by "target growth rate" but for me it is whatever the plant seems to look like in nature. So I pour over photos in books and on line and decide how I want the growth to "maximize". For instance, my Dendrobium anosmum canes are 1/3 longer this year than any year previously. That's close to 48" long!

Thanks for the thread. It was a goodie