Does seaweed actually help rootless orchids?

[Idril]

Does seaweed have any real effect on rootless orchids or it's just a myth? I mean there are arguments about whether foliar feeding exists at all and most people agree that even if it does it's just a very small amount. Do you think seaweed actually helps them survive if there are no roots left?

[Ray]

Yes, it certainly does, BUT...

"Seaweed" is too nebulous a term as there are lots of different seaweeds with varying degrees of effectiveness.

I will not claim to understand the full process of foliar uptake, but 1) not all chemicals are created the same in that regard - some are rapidly absorbed while others are not, and 2) not all plant tissue is the same either.

So... a plant that is lousy at absorbing nutrients sprayed on the leaves might be pretty good at absorbing other chemicals through other areas of the plant.

I know from personal experience and that of many others that THIS works.

[farley101]

Not sure about how it affects every orchid, my n=1 is that I had a phal with no root that I had tried many different ways to get roots to grow with no luck - water culture, damp sphag, sphag and bag, etc. Picked up some Kelpmax, soaked the base for several hours, potted in sphagnum and placed in my small heated grow space. That was 3 weeks or so ago, it has 3 new roots (that I can see) now and looks hopeful for recovery. Again that was just my experience with one plant.

[Idril]

Originally Posted by Ray

Yes, it certainly does, BUT...

"Seaweed" is too nebulous a term as there are lots of different seaweeds with varying degrees of effectiveness.

I will not claim to understand the full process of foliar uptake, but 1) not all chemicals are created the same in that regard - some are rapidly absorbed while others are not, and 2) not all plant tissue is the same either.

So... a plant that is lousy at absorbing nutrients sprayed on the leaves might be pretty good at absorbing other chemicals through other areas of the plant.

I know from personal experience and that of many others that THIS works.

I use Maxicrop. I looked at KelpMax but even the smallest bottle is much more than I can use because I just don't have enough plants. I wish it was sold in smaller bottles! I'm doing very similar to your method except that I don't plant it and don't cover with plastic bag. I just leave it bare rooted. I live in Florida so the humidity is high and I'm afraid it will rot if it gets too wet and humid. Do you think it's ok?

[farley101]

In my experience, limited as it is lol, I found that planting it in sphag was part of what was successful. The other part was having patience and not checking it every other day or more! I would check the moisture level every couple of days but that is as much care as it got. One day I noticed a half inch root poking into the medium! It had been growing for a few days at minimum, I guess all my failures previously had set me up to not expect much but it worked great. It's got a long ways to go but it's coming back!