Grow Tent Orchids
 

Anyone else using a grow tent for their orchids? I got my first one set up for my more persnickety plants! Here’s the setup: Orchid Grow Tent - YouTube

very cool,
welcome to the indoor growers scene stephen.

Where the outdoor growers manual gets thrown out the window, or at least I consider it quite different.

You will see, this will be a whole new learning experience for you, just little differences. No more seasons, no more rain, no wind.

I am curious why they make tents with a silver interior, rather than white.

Matte white absorbs and re-emits all wavelength of light in all directions, maximizing the dispersion of photons. A silver mirror reflects it only at the (opposite) same angle with which the incident beam hit it, which for overhead lighting, means down to the floor.

A textured, silver fabric is somewhere in-between, offering more scatter than a mirror, but it absorbs some of the light without re-emitting it.

As I said in another post, here is the setup I'm using when weather doesn't permit my plants to be outside. High light plants go on the top shelf. Yes, I use trays with seedling heat odds under them to try to increase humidity with some success. The light is from Orchid Hobbyist. And the fans are as follows; two computer fans running full time and one 120v muffin fan I use if I see there isn't enough airflow. The clear plastic allows sunlight from the east facing window to supplement the grow light.
https://i.postimg.cc/BQwRQmBj/20211226-094356.jpg

I just watched your video and have a question concerning your humidity problem. Is the bottom of the tent open or closed? If open, try turning the fan to blow upward, drawing drier air in from the bottom. My tent tends to stay in the 50 to 60% range with this method.

Thank you for the video tour, Isurus79!

I'm particularity curious about the results you will see following Chadwick's recommendation to withhold water in the winter for C. warscewiczii. The blooming size plant I have is in a basket that dries quickly, but it gets watered a little daily by water splashed from a tolumnia nearby that gets watered daily. Edit: In looking to see how dry it looked, I notice that it is putting out a new growth.

As to why C. warscewiczii would flower better when subjected to stress from dehydration in the winter, my only guess is that this "scares" the plant into making a last ditch effort to pass along its genes - much like a dandelion poisoned with 2,4-D. Edit: I'm now wondering if the dry period works to keep the plant from using energy reserves to grow in winter.

I have not used a growing tent so I'm curious about how you are managing the day-night temperature swings. I imagine that the LED power supply adds some daytime heat.
-Keith

according the the orchid doctor:

I just came across that yesterday..

So catasetums and deciduous dendrobiums need rest but with Cattleya's it's a fallacy? Or is it just the cattleya hybrids?

I know neofinetia don't need a rest when care guides state they do.

I can't add anything to the C. warscewiczii.

The orchid doc also says the way to get Trianae and Labiata to flower is to give them less than 14 hours of light in winter. No mention of a rest, too long light hours in winter prevents flowering with them.

Well, it's only recently (few years ago) that I got a greenhouse, so I've been a part time indoor grower since I was a 12 year old in 1992! Although this will be my first real foray into year-round indoor growing. Should be fun!

I dunno! The tent is for pot, so the guy that designed it may have been stoned?? :rofl::rofl:

The bottom holes in the tent are now open. my sensorpush tells me it's hovering around 80% today, though outside is around 90% humidity. I suspect that it's working well now. How do you get your humidity in the tent so low? Isn't Lake Charles 10000000% humidity all the time?

I suspect there is some chemical trigger that only happens during dry dormancy. Or the Chadwick advice is not true. Either way, the blooms this summer will let us know! If they're the same as previous year (weak) then the Chadwick advice isn't applicable to my conditions and I'll have to figure out when else is going on.

My sensorpush tells me I'm getting about a 5-10 degree differential. I think it's mostly related to the house temperature, though that particular room has large windows and not a lot of direct ventilation from the AC or heater (AC is being used more this winter than the heater).

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Well, I can't think of any Catt hybrids that need a winter rest. Mixing the genetics seems to reduce the need for that. Some species (I'm thinking about nobilior) do need a water rest otherwise they skip blooming and go straight into vegetative growth. However, I've found that many Cattleyas (especially bifoliates) just grow all year round if water is provided and don't need a rest for vegetative or blooming purposes.

I'd say the rest is more related to not providing conditions for rot (e.g. excess moisture, nutrients) when temperatures are low for the home grower and overwatering is easier to do.

The bottom of my tent s open to the room. The a/c is on so the humidity in the house is low to begin with. I only have four (soon to be five) plants in it, though I may change that next week. I wonder if I move the fan up and change its direction if the humidity will increase? When I first set it up as it is, but without the fan, the humidity got up to 90%
And during the fall and winter the humidity down here can get very low. As in the mid 30%s.

Stephen, thanks, still have to build up as much experience as you on the individual species,
since you bring up the nobilior. Does the rest mean the plant does no growing in this time? And then as soon as you see a new pseudobulb forming you start watering more again?

Sounds like a pretty good set up! I didn't realize the humidity get so low this time of year!

---------- Post added at 10:44 PM ---------- Previous post was at 10:27 PM ----------

This species is an odd one. It grows in possibly the most extreme environment of the Cattleyas, with close to half the year lacking rainfall. The spikes can start as early as November (my tipo should open blooms in a week or two, albeit VERY early!) but typically start in January and open from February through March.

In previous years I wouldn't water from November through April, which resulted in blooms. However, a Brazilian friend of mine who lived in nobilior habitat told me that such extremes should be relegated to nature and that the species gets regular fog during the dry season. Growers who watered less frequently, but somewhat regularly get better blooms. Now I water them (and the walkerianas, which are in similarly xeric, though less extreme environments) once every few weeks. I get MUCH better blooms with this method. I also don't see any bulb shriveling, which means I'm walking the line of giving a drier winter rest to trigger blooming but I'm not crushing the plant's stockpiles of stored energy. I feel like it's a fine line to walk, but certainly worth the effort.

I don't think that any other Cattleya is this extreme in it's growth cycle, but nobilior might be a good example of how a dry winter rest can be beneficial. I'm taking the warscewiczii plant to an extreme place (I've only watered once in 5 weeks or so), but it gives me a baseline where to start. By figuring out how dry a plant can go without dying, I can better understand a difficult plant's needs.

Of course, I'm using a 'Bedford' cross where my flowers look nearly identical to 'Bedford' which might not be the representative of the whole species. C. warsc. has several regional variants and 'Bedford' is kind of an oddball. Either way, I have a bunch of coerulea seedlings coming of age, so I might get a better understanding of the species with those plant. It's fun to figure out the cultural details of each species! Some are easy and some are tricky.

I think your last sentence is right on. What works for some, may not work for others. What makes determining optimal orchid growing conditions hard to nail down is that it is hard and rare for one variable to changed at a time.

A few decades ago I tried to grow C. warscewiczii without flowering successes in a greenhouse 1-1/2 hours south of Seattle. The summers were too cool, day/night swings too shallow, and direct sun would shine only a few days a year. Here in Mississippi it is probably not too different from Texas. The summers are hot, day night temperatures swings are the ideal 15-20F, and sunlight is abundant.
I often wonder why a couple weeks of unseasonably cold wet rainy weather doesn't wipe out entire orchid species.
-Keith

---------- Post added at 12:03 PM ---------- Previous post was at 11:48 AM ----------

I think your last sentence is right on. What works for some, may not work for others. What makes determining optimal orchid growing conditions hard to nail down is that it is hard and rare for one variable to changed at a time.

A few decades ago I tried to grow C. warscewiczii without flowering successes in a greenhouse 1-1/2 hours south of Seattle. The summers were too cool, day/night swings too shallow, and direct sun would shine only a few days a year. Here in Mississippi it is probably not too different from Texas. The summers are hot, day night temperatures swings are the ideal 15-20F, and sunlight is abundant.
I often wonder why a couple weeks of unseasonably cold wet rainy weather doesn't wipe out entire orchid species.
-Keith

I grow all my orchids in the tent with the exception of my phals which live in the bathroom. Everything seems to grow fine for the most part but I really don’t have a reference point as this is the only experience I have. Temp is 67 night - mid to high 70s day with around 80% rh. I run a fan 24/7 and decrease photo period by a couple hours over the “winter” months (14 summer/12 winter). The one plant that is currently stumping me is mo. Painted desert x ctsm John c burchett…it doesn’t seem to want to flower. This is the second season I’ve had it and it produced a 17” growth this year. Not wanting to hijack the thread but thought this might be a good addition in relation to seasonal requirements and shortcomings with a tent.

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Either they don't get cool weather in nature or the cool weather on our collections is the straw that broke the camel's back, likely just being the tip of the iceberg of cultural problems in our artificial environment.

---------- Post added at 12:51 PM ---------- Previous post was at 12:50 PM ----------

You might want to take it down to 10 hours in winter. I bet that triggers blooms for you!

I shall give it a try!

I think you'll enjoy growing in a tent. Here's an updated pic of my 4'x4'

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Hi Ray. I see your point. But I have watched many youtube videos from apparently independent parties in which all kinds of materials were used and measurements were taken in many different spots with a professional/calibrated PAR sensor. The textured silver fabric provides the highest available PARs, but this is true only for the good quality ones, which are quite expensive. However, a nice flat white surface provides almost the same PAR (about 5% less, or so). So the question is: is it worth it to spend more money for that?

In my small stealth growing cupboard. which has white surfaces, I eventually installed the mylar. I did some measurements and I got slightly better results than the white surface. I did it only because the mylar is very cheap, otherwise it would have not been worth it...

Dav

I’ll bet you made your measurements in a mostly empty enclosure.

Consider the following scenario - the grow tent is 2 meters tall, by 1 meter wide and deep, and light source is a point emitter in the very center of the ceiling. Physics tells us that if the surface is mirror-like, light striking the wall 1 cm from the top will be reflected at an equal angle to a point 2 cm below the lamp in the middle; light striking the wall 2 cm below the ceiling is reflected to 4 cm below the lamp in the middle, and so on, until light striking the wall below the 1-meter mark gets reflected to the floor, never reaching the center of the floor. That’s probably OK, as there has been light reflected from all points on the entire interior surface, plus that going, unreflected, directly from the light source.

Sounds good, right? Maybe not…. Now let’s put plants in the tent. Light striking them goes essentially no further, whether that is direct, or reflected off the walls, making the volume below them darker - that ray of light that might have struck the wall at 50 cm down the wall no longer reaches it, so the plants at the 1 meter height never see it.

If, on the other hand, the walls were matte white, the light hitting them is no longer reflected at an equal and opposite angle, but is absorbed and reemitted in all directions. That means that while that “50 cm ray” is still blocked by the plant, preventing it from reaching those below, those rays striking the walls above and below that point are scattered sufficiently to still reach the plants in the shadow from the plant above. Not only that, but light rays hitting the wall are also scattered upward, illuminating the undersides of the leaves, essentially creating a more uniform illumination throughout the tent - something mirrors cannot do.

This is an extremely simplistic scenario, as lights are not point sources, shelves block light, and no interior is a perfectly mirrored wall, but that actually makes the scattering effect of a white wall more important.

Shoot, I was unable to access the Google drive, but checked out your Instagram profile and saw the set up! Very cool looking! What type of light are you using?

---------- Post added at 07:23 AM ---------- Previous post was at 07:21 AM ----------

Ray - I think you found your next new product for you website!

Stephen, I fixed the link permission, not sure why it changes, maybe I need to use Flickr or something else.

Lighting is via two 100w HLG sabers dialed down to around 65w each.

I have thought about the wall myself. I've used light hoods that reflect light down, I've used white light sheets and mylar. Have I noticed any difference?
I even did some lettuce comparison tests at one point.

In practice the difference is negligible.

Even if a wall reflects light at 95% vs 90% the light actually coming out of the light unit is what gets absorbed most, if you use a light hood it gets directed even more at the plants. Anything that hits the walls hits the walls, then hits the floor and gets refracted back up again.

But by the time the light that has travelled that distance and hits the underside of the orchid leaves it has lost so much energy whether it was reflected twice off a 90% surface or 95% surface is in practice truly negligible.

To think about it a bit more, the more a tent gets filled, the more mounts get hung up on the walls, the more the canopy fills the tent.... the less light hits the walls.

Most tents I have eventually seen are filled with orchids, every nook and cranny of it.

In a situation like that it makes even less difference whether the wall is white or silver since so little light is hitting that area - the orchids will be absorbing most of it.

Even with lettuce as long as most of the light is aimed directly at the lettuce I didn't notice a big difference, tbh the lettuce never grew very well in either situations lol.

I like thinking about these things - to me the light unit is the most important and the material used for the walls is 20% important compared to it? So overall it probably makes a 1% difference in 10 years growing orchids.

Whats 1% of 20 flowers? An attempted flower? So instead of getting 20 flowers I would predict with a better reflected wall one would achieve 20 flowers + an attempted flower.

With so many mounts, is your tent situated over a catch basin for watering? Nice setup.

Yes, I believe it was listed as a hydroponic tray (normally used with a table growing setup). It is 3'L x 3'W x 8"H.

Here are pics of the tray and light bars for reference.

hydrotray.jpg - Google Drive

Sept 2021.jpg - Google Drive

White paint?

yes

Whitest paint ever reflects 98 per cent of light and could cool homes | New Scientist

No, grow tents with the appropriately colored interior

With the lighting being used I’m guessing the difference is negligible. But I could be wrong. 🤷

Many of the earlier white interior grow tents in the US suffered from degredation of the plasticizers, and ruined peoples' harvests.

The gain from silver to white is minimal in regard to the primary requirement of a grow tent, immediate portability.

That is why there isn't a push for white interior grow tents.

Good to know!

Hey y'all, I'm considering getting a Mars Hydro grow tent, preferably one of the smaller ones. Could I have a full tent without splurging on the proprietary equipment from Mars Hydro, like the LED panel and fan setup? I have seen people use their tents for orchids and all the photos look to have beautiful and happy plants, but the whole thing costing ~200 dollars for a 2x2 tent is a bit much for me.

People sell their used tents and lights fairly often. You might be able to find a good deal online.

with Mars Hydro you are just paying for the name and a crap product.

Generic 2 x 2 grow tents go for £50 on ebay.

A good grow light is £50

A mars hydro light is rubbish.

a bathroom extractor fan and a mini oscillating fan is all that is needed.

£15 for each

total £130 so maybe a bit more in dollars.

If you apply the -20% voucher then this light works out to about 50 dollars:

Amazon.com

Stephen inspired me to set up a grow tent last fall - I started with a 4x4 but recently scored a cheap used 4x8 and added another light/shelf. So far it's been a dream to use.

I keep it in my basement in Michigan with two Spider Farmer SF2000 lights. I have two fans and a humidifier running 24/7. Daytime temps hover around 80, night drops to the 60s. I expect these #'s to bump up a few degrees in the summer but the location in the basement will blunt most of the seasonal swings I'm guessing.

Humidity stays pretty steadily in the 80%-100% range. With all the airflow I haven't had any problems.

I basically only have one orchid that isn't thriving, a chiloschista, the rest seem to love it. I know I love it, it has turned into my happy place, especially in the dark cold MI winters.

Damn that's an impressive setup! Have you calculated the montly electricity costs?

I hadn't given it too much consideration but here's a quick back-of-the-envelope calc. My electricity rate is ~$0.10 per kWh.

Lights: 400W * 14hrs * 30days / 1000 * $0.10 = $16.80

Fans + Humidifier = 110W * 24hrs * 30days / 1000 *$0.10 = 7.92

So I'll round up to $25 a month. I'm probably overestimating the wattage a bit on the fan/humidifier side but even so the cost is mostly driven by the lights. Fortunately the lights are very efficient.

When it comes to looking at my bill, year over year it's not noticeable b/c the natural variance in my bill is more than $25. Turns out keeping me warm and happy is a lot more expensive than keeping the orchids warm and happy...

I'm glad you posted this. I'm planning a move to Michigan later this year and have been wondering how I'm going to set up a grow area. This gives me tons of ideas, and the cost factor is reasonable. If it gets to be too expensive to keep the house warm, I'll just move in with the orchids!:lol:

Welcome in advance! It's really a beautiful place if you can stomach the winters, and we have some very welcoming orchid societies. I know quite a few people with greenhouses up here so it's not like that can't be done, but in terms of affordability the tent is pretty great. And in my opinion it has a lot of advantages over a greenhouse.

By far the most expensive part (excluding the plants) is the lights. The ones I went with run about $250 each.

I have considered just turning my basement into one massive tent and spending all my time down there :) maybe someday.... they do sell 8x8 tents!

Where in Michigan? My plans include Alpena area.

I'm in the Lansing area, I'm only aware of the lower/mid Michigan orchid societies but I'm sure there's something up in Alpena!