Indoor Grow System

Anyone have any experience with ‘indoor’ grow systems? I don’t have a greenhouse and use my garage for my tropicals during winter (i live in north houston and winters get consistently 40’s-20’s which is too cold for tropicals to thrive … and theoretically would love to keep optimal growth for 12mo/year since they don’t require dormancy)

anyhoo all the internet data (and online stores) are clearly weed-related so it’s hard to find good info for our horticultural niche

space is about 10x10’ and i’ve been told i should use metal halide 1000w system per 5x5’ space


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It’s important to get a fan or two for air circulation too

Metal halide is the gold standard, but full spectrum LEDs and fluorescents are workable too.

The other three issues are humidity, temperature, and air circulation.

Air circulation is easier; point a fan at the bonsai.

Temperature is relatively easy; if you aren’t keeping it warm enough with lights, buy a heating pad.

Humidity is harder; to get humidity above ~50% in a normal western house that runs its HVAC frequently, you’ll need either (1) a relatively small room and a pretty serious humidifier that you’ll have to refill frequently, clean frequently, and that will likely damage plaster/furniture/carpet/etc. over time, or (2) a completely enclosed terrarium and a more humble humidifier.

You nailed it in your original post: what you need is a greenhouse. As far as I’m concerned, the best indoor setup is likely a giant enclosed terrarium with a lighting array for its top, with a humidifier, and, as required, a heating pad.

Coda: this problem comes down to cost versus reward. An indoor greenhouse is an expensive way to replicate a climate that doesn’t exist where you live.

Are you cool spending ~$400 on a good-quality glass terrarium, lights and humidifier, all for enough space to grow 1 decent-sized tropical tree? Go for it!

Too rich for your blood? Stick with natives and the climate you get for free. :slight_smile:

thanks for your thoughts … for me it’s more an over-wintering solution for my tropicals, specifically, to prevent death … and if possible, optimize growth

i’m at least 1 house (and a lot of research) away from being able to have a ‘real’ greenhouse.

your point is well taken regarding growing natives - i’m not ready to give up though - houston is weird - it’s perfect for so many species for so much of the year, but has these occasional (but predictable/definite/consistent) extremes that make survival dicey for some species - tropicals are the best example - they thrive for 48 weeks of the year but i inevitably get some weather that’s deathly-cold for tropicals a few intermittent and random weeks of the year. …

truthfully, on a practical level, it’s just too hard to move that many trees in and out of temporary protection for the few random weeks it gets to freezing temperatures

anyhoo; i digress

in short: planning on garage storage which has some windows for natural light (but not enough to to provide good health), i anticipate humidity will be ambient w outdoors, temp will be warm due to lights, and will have fans for circulation

i’m going to follow the ‘weed’ instructions of 1000w per 5’x5’ area and see what happens i guess

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FWIW: I live in southern Louisiana – similar climate – and overwinter many of my tree inside under fluorescent grow-lights and next to a large humidifier and it works fine for the 3ish months it gets cold.

cool - about how many trees, how much square footage and how big are your lights?

I’ve got one of these:

And it covers 3 trees.

I’ve also overwintered several very young trees under two T4 bulbs and a south-facing window.

I ended up making the investment in 2 1000w metal halide systems which should provide ample space and light for the trees I have; I’ll post more updates once it arrives and I start setting it up

Thanks for all your input and thoughtfulness

Last year I kept my tropical/sub-tropicals in front of my Family Room patio door on a multi-level wooden stand. I’ve added to my collection this year so I bought a 5 shelf system at Home Depot, and 6 Sun Blaster LED Full Spectrum lights. Attached is a picture of the stand in my basement. I have since added some 6 inch fans to stir the trees. I placed three aluminum cookie sheets from the Dollar Store underneath the stand to catch any spills. We’ll see how it goes.


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looking pretty solid; just got my light system delivered yesterday so will set it it up and post pictures

Finally got it 1/2 setup (comments below each photo):

the child is included for size reference, and because i find her cute; in short: a 1000w system with the air-cooled reflector is huge; dimensions of the reflector are like 18x24x10

big bulb! 1000w metal halide; supposedly LED works well too; honestly i didn’t feel like doing the research; i knew MH was ‘industry standard’

this is the ballast - it is digital (as opposed to magnetic) and allows for more quiet running as well as ability to dim the lights to 50 % or 75%

I built this pretty simple frame (bulky and cumbersome but light and can move it by myself) to hang it from - needed something that would fit under the garage door.

the light system came with some nifty hangers which the height can be adjusted with

I have them on a timer for 14h/day; they’re tropical, let’s go big

still have more work to do as my larger (only mid sized) trees still need to come in; they’ll be under the higher garage ceiling (no garage door to deal with); so i’ll need to put some hooks into some studs.

I’m sure everyone wants to know - cost? For lighting system alone (so excluding my frame/fan/etc) it was about $315 out the door w taxes/shipping/etc.

I have fans hooked up; only other unsolved problem is figuring out a good drainage system so the water doesn’t collect in the garage and make a mess.

on a funny note, I feel like i’m probably on an FBI watch list and will likely be reported by my neighbors to the cops for growing weed.

best for last, the grow system came with a free sticker i’ll be sure to put on my car:



In the U.K. the cost of running that system would have been around £20 a week. $100 a month. Looking good though but an expensive thing to maintain. The bulb will over time need replacing they loose output over a few months. I’m interested to see the results. Ps the bulbs produce a lot of heat too. Have fun. Ps. Fresh air is also real important.

yeah i’ll be keeping an eye on the electric bill; it’s really just a glorified over-wintering system for 4mo/yr to #1 protect from freezes and #2 try and optimize growth; i figure with the fan and the garage door being opened at least 2x/day it should have reasonable circulation

So far the trees appear to be responding well - ie they’re continuing to grow and have no e/o burn or wilt


Looks great so far!

My only comment would be that the light could probably be closer to the leaves. It’s a fine balancing act (and more about heat than light exposure), but you might see better results by lowering it, especially once you’ve got fans hooked up.

Also re: “responding well”: in my experience, indoor lighting systems begin to show tree failure 2-3 months in. So keep an eye out around then!