Evidence for foliar watering/feeding

[terryros]

I can find various opinions about the success/failure of foliar feeding of orchids. Some claim foliar uptake to be better than root uptake while others carefully avoid getting solution on leaves to avoid crown rot.

Do you know any scientific evidence concerning the ability (or lack thereof) for the stomata of orchid genera to take up water/nutrients?

[johnblagg]

I did read a couple of things about some research done in this area in which they used a radio isotope to trace the uptake of nutreients by foliar feeding.

They do indeed take in nutrients from foliags but from the underside only the waxy top surface of leaves is very water proof and in fact stomata are on the underside I believe.the radio Isotopes did move throughout the plants from foliar application so how effective I dont know but it does happen to a extent.

I do use weak fertilizer to spray mine and while you do need to be carefull of letting them sit wet for long I have no problems with rot from watering .......neither in phals and dens or my catts so far .

Mine do sit outside under a tree in warm weather and get watered mostly by rains and a once a week pray with fert also they also get the natural breeze and anything that the rain washes down out of the tree just like they would growing in the wild.

So far I have only lost one phal and that was due to getting too dry inside this winter and was a very small new plant ...they get sprayed inside to water more than watered by watering medium in the winter.

[Cym Ladye]

Speaking strictly from personal experience, I have used foliar feeding as well as deep fertilizing on my Cymbidiums for 30+ years and my plants thrive. Some orchid fertilizers are better suited for this purpose.

The time of day plants are watered is critical however, as the stomata on the underside of the leaves are open at night, but generally not during the day. Therefore, to avoid water staying too long in the leaves, early morning, before the warmth of the day causes the stomata to close, has proven to be the best time for me.

CL

[johnblagg]

Most often it is the waxy hard leafed types in question .....the thinner leaves types it is generaly assumed are more lke any other thin leaf plant and not usually questioned as to whether or not they adsorb fertilizer through leaves ....

the same applies to waxy leaved chids as it would to any hard waxy leaved plant and I have always applied foliar feeding unless it would damage somehow ...IE african violet leaves or a whit deposit building up.

I personaly believe almost any plant will adsorb through the leaf surface that has stomata on it .....

the one exception I might think of would be cacti which are almost impervious to water ...and I still use it on them also but--- lol in that case it runs straight off and into soil. and cacti like most chids open stomata at night and take in co2 then and use it during the day while the stomata are closed.

[annie1931]

Forgive me if I am interrupting, but I was looking for comments about spraying as opposed to watering with the water pot and found the post re foliar water.

I spray my orchids and very seldom pour water into the pot. It was most interesting to learn that the undersides of the leaves carry the stomata - I think that's been a stumbling block to the care of two 'rescued' orchids. Crown rot was mentioned, and I can see where my spraying just on the leaf tops would cause that. I have one huge orchid (Phal.) that is just now losing the 42 blooms it's had for the past 3 months - it has such a snake-pit of a root system I pour fertilized water into the container where many roots have grown toward and into, and spray with plain water the roots growing upward. The backs of the leaves get quite a bit of spray though inadvertently.

The other two Phal. orchids are blooming but one is losing leaves...I will amend my watering approach immediately for both of them and see if they improve.

[johnblagg]

Originally Posted by annie1931

Forgive me if I am interrupting, but I was looking for comments about spraying as opposed to watering with the water pot and found the post re foliar water.

I spray my orchids and very seldom pour water into the pot. It was most interesting to learn that the undersides of the leaves carry the stomata - I think that's been a stumbling block to the care of two 'rescued' orchids. Crown rot was mentioned, and I can see where my spraying just on the leaf tops would cause that. I have one huge orchid (Phal.) that is just now losing the 42 blooms it's had for the past 3 months - it has such a snake-pit of a root system I pour fertilized water into the container where many roots have grown toward and into, and spray with plain water the roots growing upward. The backs of the leaves get quite a bit of spray though inadvertently.

The other two Phal. orchids are blooming but one is losing leaves...I will amend my watering approach immediately for both of them and see if they improve.

Your post is no way interrupting but rather right in line with the subject I would say!

I spray any root that are visable with my fertilizer mix as well as the underside of leaves.

This one gets a regular spray of fert on all roots showing and they have really took off ...the pot is quite full als but since I use rice hulls for my medium really dont need much watering and the runoff from the spray usually does it.All of the roots showing are from this last winter and I am thinking of letting this one grow onto a mount from here.
http://www.orchidboard.com/community...-phal-now.html

Its kind of funny how the roots all decided to grow the oppisit direction from the crown

[Cym Ladye]

Annie,

If your Phal has roots growing out of the pot in the manner you say and is through blooming, it sounds like a perfect time to repot!

CL

[annie1931]

Regretfully, repotting is not an option - I do not have room for a larger pot in my very limited-space condo, and it will just have to manage. The pot would have to be smashed, too, as the roots have grown out through the holes and down into the water. I shall have to tie up the upward-growing roots soon to keep them from ensnaring us at dinner time.

[Cym Ladye]

Annie,

Repotting does not necessarily mean going into a larger pot. From what you say about the roots, it it only a matter of time before your "semi-hydroponic" growing will move you out of the condo! A repot may in the end take less room, as you will be cutting some roots and confining many of the remaining roaming roots to a pot.

Just my on the subject.

CL

[annie1931]

Hmm. My next comment would be that I have no idea how to extricate Blanche (yes, that's its name) from the holey pot.