Yellowing Leaves and Dark Areas on Vanilla Orchid Cutting

[Roberta]

Originally Posted by NeonKraken

Sorry to interfere or change the subject, but did anyone have any further thoughts about the fan running 24/7?

I run my GH fans 24/7. In an enclosed space, one can't have too much air movement... the more enclosed, the more important that is. Succulents may not care, but orchids in general benefit from gentle air movement all the time. (A cold draft can cause Phalaenopsis buds to blast, so do emphasize the "gentle" part)

[NeonKraken]

I guess my main concern would be it getting to cold/too much air circulation as it is a relatively small space. Its about 3.5 ft wide and maybe 3 yards high. The shelves are around 3.5 x 2 feet.

[Roberta]

Originally Posted by NeonKraken

I guess my main concern would be it getting to cold/too much air circulation as it is a relatively small space. Its about 3.5 ft wide and maybe 3 yards high. The shelves are around 3.5 x 2 feet.

A small "personal" fan, on low, would gently move the air without creating a gale. When a fan turns on and off, it is more likely to create a draft. A gentle, even air flow should be fine. If the room is cold it might be an issue. But if the ambient temperature is comfortable (or even a little warm) for you, it should be perfect for the plants. What they don't like, in addition to stale are, is abrupt change. So, again the constant, gentle air flow wins over the "on-and-off" scenario which really can produce a draft that the plants don't want.

[NeonKraken]

That makes sense. I will check if it has a low setting. The temperature outside is pretty warm but the room gets pretty cool, so I'm not sure if that would be a concern.

[Roberta]

Originally Posted by NeonKraken

That makes sense. I will check if it has a low setting. The temperature outside is pretty warm but the room gets pretty cool, so I'm not sure if that would be a concern.

As long as the temperature stays fairly even, the plants will adapt. Remember, too, that you feel cool when a fan blows on you because you can perspire, and so feel evaporative cooling. For plants that's not an issue. So a vanilla plant can be quite happy in a room with a gentle breeze at 75 deg F, and that will feel cool to you when it is 90 deg F outside. If the A/C is blasting then you want to shield the plant from that.

Think, for a moment, about where vanilla orchids grow naturally - in the tropics, where the temperature range over the course of 24 hours is probably something like lows of 72 deg F, and mid-day highs maybe close to 90 deg. F, going up and down gradually, almost always with a breeze, and with high humidity (and frequent rain) It is climbing up trees, so its roots are exposed to the breezes, getting wet when it rains and dry when the sun comes out. Of course, you can't match that in your house (or even in a greenhouse) but you can seek to come as close as possible. That "bed" of sphagnum moss provides the "humidity" in the immediate vicinity of the plant (and hopefully encourages some roots) The gentle fan keeps the air moving, so that fungi and bacteria don't have a chance to gain a foothold. You'll get surface drying, then you add water and it is "raining". Anyhow, that's the goal - in general, look at what you're trying to accomplish, then look at the many ways that you can do that.

[NeonKraken]

That makes sense. I will check if it has a low setting. The temperature outside is pretty warm but the room gets pretty cool, so I'm not sure if that would be a concern.

---------- Post added at 10:18 PM ---------- Previous post was at 09:57 PM ----------

Oops! Sorry for duplicate post.

[Ray]

NK - there should be mild, tumbling air around your plants at all times. That does not mean a fan blast directly on them, nor does it need to be a hurricane force. It will be beneficial to all of the plants.

In addition to helping plants dry off after watering, eliminating little pools that can become incubators for molds and bacteria, preventing temperature stratification within the growing area, and discourage the settling of mold spores (they're everywhere), all those little pressure changes passing the plants draw fresh air through the potting media, helping the plants' gas exchange processes.

[Swimmingorchids]

kraken, all of the above advice is sound but as to your question, for the small hobby grower a fan is really not needed.

I have one enclosure which is a sealed aquarium and the only ventilation it gets is 2 little pencil holes.

Like I said all the above advice is sound, ventilation is key to preventing pooling water and mold but for the small hobby grower who should be checking on his plants daily you do not need to invest in a fan.
That is my 2 cents on the matter

Also everyone her is forgetting we are talking about a weak plant that should be sealed in a plastic bag planted in some damp spagnum with minimal ventilation - humidity in the 90% range till roots show...

There. hope that helps.

[WaterWitchin]

I respectfully disagree with the advice about no fan. First, good humidity. Then, if I had the choice of R/O, rainwater, or tap water, fertilizing, or a fan... the fan would win hands down. "Sealing" in a plastic bag with no air flow is a good way to finish off the plant.

I'm aware we're talking about a cutting off a vanilla vine. I know it requires RH around 80%. The air roots need to be watered or misted, then dry rapidly.

A vanilla vine (orchid) is part terrestrial, part epiphytic. The air roots on this cutting aren't getting enough moisture. The medium is likely being allowed to dry too much before hydrating again. It's a cutting. We have no idea what the portion of the cutting that's in the medium looks like. Were there air roots on the cutting that's in the medium?

Get rid of the pole for now, concentrate on getting terrestrial root growth and keeping the air roots alive, although the ones I see look pretty dried up.

Edited to add: I went back to the original post. It appears you're growing on covered shelving (like with the plastic covering?) so you already have the "enclosed" part under control. I would bet your humidity isn't high enough. Or don't get rid of the pole, and make sure the moss on it stays moist all the time. Get your fan set up and blowing in there. Could you have it point to the "wall" of the enclosure and let it blow hard enough to circulate that air movement back around? The "tumbling" effect of air we're talking about?

[Swimmingorchids]

well I am clearly in the minority on the matter which is fine.

I don't want to give any bad advice so I will just show whats been working for me to keep humidity high.



Been keeping my orchids enclosed like this and only issue I have encountered so far has been mites but they arrived from the shop..

Out of curiosity.. Does anyone know of any good mini solar powered fan that could provide the ventilation I am missing?