Two growers, Simon from Montreal and Ian from Michigan, have completely opposing views on vertical growing. Simon loves it, whereas Ian loathes it. We thought it would be fun to get them both on a conference call and let them hammer it out. What follows is an abridged version of a two-hour-long heated debate! Brace yourselves—this ain’t gonna be that polite or pretty…
Vertical Growing in a Nutshell
“Noob” growers often scratch their heads when they first hear about the concept of vertical growing. “Don’t plants grow upwards normally?” they ask. So let’s get the difference between horizontal (regular) growing and vertical growing sorted out straight away.
Horizontal growing is how most gardeners (indoor and outdoor) work. Plants are grown in pots or systems along a horizontal plane, and the grow light/s are positioned above the plants, mounted in a reflector so that the light gets beamed down to where it’s needed.
Vertical growing involves positioning the plants in a 360-degree formation around a grow lamp (sometimes in a cool tube but using no reflector). The general idea is that you maximize the use of the height in your garden, and make the most all that precious light energy without the use of reflectors. Plants in vertical growing systems tend to be a lot smaller, meaning shorter veg times but far greater plant numbers.
Everest: Okay guys, thanks for joining us. Now I know you’ve been blasting each other on the forums and you’re probably bursting at the seams to get going with this one, but first, can you each talk a little about your growing experience so the folks out there have an idea about where you’re both coming from?
Ian: Sure—I’ve been growing indoors for just over ten years. I started with potting soils, played around with most hydroponic systems (NFT, drip, ebb and flow, aeroponics) and a huge variety of growing media, and now I grow with coir using pots in a homemade drip system. I’ve stood by while some of my friends tried, and mostly failed, with vertical growing systems and even helped a few manage them for a while, which is why I would never recommend one to an interested grower.
Everest: Easy now Ian, we’ll get to all that. What about you Simon?
Simon: Well I’ve been growing on and off for around 15 years. I started with soil; I think 99% of people do. Then my local grow store switched me on to coco. I’ve tried clay pebbles too, sometimes mixed with rock wool croutons. I’ve run ebb and flow, NFT, drippers you name it. I’ve tried and failed with aeroponics but, to be honest, it was down to my ineptitude rather than anything else. But unlike Ian I don’t dismiss a technique out of hand just because it didn’t work for me. I’ve been running an Ecosystem since they came on the market. I’ve got my best results ever from vertical growing—it rocks!
Ian: Hang on, I’m not ‘dismissing’ vertical growing and, no disrespect, but personal bests are relative to the person. I’m just here to argue that vertical growing systems are not all they’re cracked up to be. I’m not even going to bring into the argument the phenomenal cost of vertical systems, which is enough to put a lot of people off. I want to focus on the practicality of using these systems, and why they suck.
Simon: There you go again. Why do you have to say “they suck” like that? I’m here to, hopefully, participate in an intelligent discussion about vertical growing. You mentioned practicality. Well, first off, vertical growing systems are a cinch to set up. Take the Ecosystem and Ecosystem 2 for example. They are ready to go gardens: lights, growing media, irrigation, reservoir—ready, steady, grow. All you need to do is take care of the growing environment.
Ian: You make it sound so easy! Ha ha. But ok, this I’ll give you. Some vertical growing systems are very quick and easy to set up. Others though, are a horrible arduous chore! I’ve had the joy of filling a Coliseum—300 plant sites with 3 x 1000 W lights—with a 265 gallon mix of perlite and vermiculite and, boy oh boy, it was a nightmare! It took the two of us the best part of four hours, and I’m not talking transplanting, just filling the system with growing media! Never again!
Simon: You’re talking about growing 300 plants. And duh, guess what, that involves preparing 300 plant sites. Sorry if you’re work shy Ian but, of course, it’s going to take some labor to prepare! If I could find a system that filled itself with grow media, emptied itself, and replanted itself, I’d probably go for that, but …
Ian: Now you’re being both dumb and facetious Simon. But at least you’ve made a salient point against vertical growing on my behalf! Aren’t we really talking about making the most from your grow lights—in this instance, 3 x 1000 W. Don’t we need to ask why 3 x 1000 W grow lights should necessitate 300 plants in the first place!? It could just as easily light 18 large plants in five-gallon pots, spread over three, 5 x 5 ft ebb and flow trays. It’s going to take me … what … 10 minutes to fill 18 pots, not four hours to fill 300 plant sites?
Simon: And how long to veg up those “18 large plants” you mentioned?
Ian: Well, with six plants under a 1000 W … 10 days, maybe two weeks?
Simon: (Cackles) two weeks! That’s ridiculous! Compare it with my two-day veg time for micro-plants in a vertical grow. My crop cycles are nearly half a month less than yours. You’re getting what … a maximum or five crops a year, whereas I’m always pushing six, using less energy too as I don’t have to have veg lights on for 18 hours a day for two weeks—ouch! I wouldn’t like to see your electricity bills!
Ian: But what about your plant numbers dude! They must be astronomical! In vertical systems you need anywhere between 80–300 identical cuttings for a two- or three-light system. In my four-light room I grow 24 plants, and to prepare for this I take 40 cuttings from one donor plant. Seems a little excessive to some but I only select the healthiest 24 with identical branch and node formation, the others I trash or give away. This selective approach helps me achieve a very uniform crop, level canopy and consistent yields.
Everest: That’s all cool and the gang, but what about Simon’s point on veg times and energy usage? Doesn’t that concern you at all, Ian?
Ian: Well it all sounds so wonderful in theory doesn’t it? Veg under metal halides for a few days and transplant into the system and bosh—straight into flower on a 12/12 light cycle. That’s what my buddy did and he found, due to the small veg time in the system, that some plants did not establish well enough and got left behind while others over grew and over shadowed them.
Simon: I’ve had that problem too. I overcame it by making sure that roots were simply exploding out of the rock wool cubes before transplanting into slabs. (Not just one or two.) I make sure those slabs have been pH adjusted and I water in my transplants individually with some CANNA Rhizotonic and a mild, balanced bloom formulation at around EC 0.8 and pH 5.5 – 5.8. I veg in the slabs horizontally for a couple of days, allowing the cuttings time to anchor in a little. Some plants will always outperform others—that’s natural. But I still end up with a beautiful canopy, either way. The trick with vertical growing is to select the right sort of phenotype that doesn’t stretch and get all gangly. You need to really know what you’re dealing with.
Ian: Yeah, yeah, but back to uniformity of cuttings for a moment; it’s easier said than done. And it’s so important to get right with vertical gardens, where plants are grown very close together and need to be kept small and squat, so identically sized cuttings are even more essential. This means for a 300-plant system I would have to take at least 400 cuttings (preferably 500), which means needing loads of huge donor plants to take them from. For my four-light room, I have a two-tiered shelved propagation tent, which is 4 x 2 x 4 ft, this houses two short stocky mother plants and my cuttings. To take a batch of 400 cuttings you’d need an additional two-light grow room! How is that saving space, let alone energy? It’s just shifting it all somewhere else! The whole thing’s a poorly marketed gimmick.
Simon: Yeah, you need lots of uniform cuttings to make vertical growing work, and not all plant species or varieties are suitable. Yeah, you need to know what you’re doing. I wouldn’t suggest this technique to a beginner. But the fact remains, I’m pulling six crops a year, you’re pulling four or five. I produce the 140 cuttings I need for my Ecosystem from two bushy mother plants under two x 400 W metal halides. Perhaps they aren’t always as uniform as I’d like though. More mother plants would help. I root them in several standard propagators under two banks of High Output T5 Fluorescents. And I veg them into rock wool slabs for two days under 250W metal halides.
Ian: But two days isn’t enough veg time. The plants can’t lay down good foundations for their flowering cycle in such a short space of time. Also, wouldn’t you agree that with vertical growing it’s not about less work for the grower, it’s more that all the work shifts to propagation? Stressing over hundreds and hundreds of cuttings is not my idea of enjoyable indoor gardening. I’d rather be chilling and admiring my plants in my flat bed garden.
Simon: Well I guess we’re going to have to agree to differ on that one. Chill all you want with your five crops a year. I’ll happily “stress” over my six crops a year, thanks very much!
Ian: Yeah, I know yearly yields can be increased with short veg times, but six crops a year can be done with sea-of-green growing in horizontal gardens too, not just in fancy vertical systems. I’ve played around with higher plant numbers using ebb and flow trays, and can appreciate the quicker turn around, but as I’ve already said, the time and effort invested in preparing the garden and propagating the plants to get these larger yields is not worth the effort in my humble opinion.
Everest: Okay, let’s move on to another key component of vertical systems: cool tubes. Most vertical systems use glass air-cooled tubes to remove the heat from the lamp so the plants can bask closely to the light.
Ian: Yeah, but surely these tubes lower the amount and quality of light reaching the plants? I chatted to the guy at my grow store about this and he reckons that curved glass reduces light intensity by around 5% in comparison to flat glass which is around 3% compared to the open style reflector. Also, light tubes are not user friendly; I like to veg and finish my plants with metal halide lamps, using HPS in-between. Ever tried to swap out the lamps on a vertically mounted cool tube when there are loads of plants in the system? Trust me, it’s not easy.
Simon: Sure, glass stops UV (which promotes the development of essential oils) and diminishes light intensity a little, but this is all more than counteracted by the fact that you can get your lights closer to your plants. Also, many Ecosystem growers here in Montreal don’t use cool tubes at all; they simply drive lots of fresh air through the system. I’ve seen plants just inches away from 1000 W lamps! With enough air movement, they’re okay.
Ian: You’ve got to wonder about the potential for all those plants crowding out a cylindrical vertical growing system; there’s a fixed distance between the light and the canopy, which cannot be adjusted on most designs. This means as the plants grow from the system toward the light, the total canopy size decreases as the crop grows! Think about it. Most vertical systems are circular; as the crop grows it gets closer to the light so the circular crop canopy starts off the same size as the system and gets smaller as the canopy approaches the light. Not to mention the plants grow into an area of high light intensity, perhaps too high, as well as into an area of higher temperature. The only way to get around this is to have the option of moving the plants further away from the central light column, and most vertical systems simply don’t have this functionality.
Simon: You need to get multiple factors right for a good vertical grow: a plant variety that doesn’t stretch and go all leggy; the right number of those plants, and the right amount of veg time. Most growers who mess up in vertical simply over-veg their plants.
Ian: Yeah, but all the planning in the world doesn’t make up for a hot spell that causes your plants to stretch. There’s just a lot less margin for error in vertical grows. Whereas in my horizontal garden, I simple lift the lights when I need to, with no reduction in canopy size.
Simon: But what about efficiency! Growing plants 360 degrees around a lamp means every photon has a direct path to a leaf, rather than relying on reflectors (which can reportedly shift spectrums and collect heat) to bounce them.
Ian: This argument for vertical growing is the most common and convincing—you get to make the most out of the light emitted from the whole lamp, without the use of a reflector.
Vertical Grow Species Selection
You HAVE to use plants that grow short and stocky, and have extremely tight internodes. Experience with growing the variety in horizontal gardens is a must. You need to know the ins and outs of every aspect of the plant before attempting to grow it successfully in a vertical garden: Is it particularly susceptible to transplant shock? Does it produce fast, anchoring roots? How much stretch does it put on when triggered to flower? Does it respond well to frequent pruning into a single stem? Can it support its own weight without any plant supports? It is resistant to fungal diseases, particularly botrytis?
Simon: Finally, you’ve managed to say something positive about vertical growing.
Ian: Don’t get too excited. I’m not done yet. With almost all growing systems, the workload is more at the beginning and end of the cycle, but with vertical growing the workload can easily lead to a lack of motivation to get going again. The timing has to be spot on to get the crop cycles right and it’s no easy task. The buddy I helped with the Coliseum took at least a week to turn around a harvested crop into a newly planted one, which obviously ate into the salesman’s promise of six crops a year.
Vertical Grow Environmental Control
Maintaining short, stocky plants in a vertical growing system is a must. Poor control over temperatures in your indoor garden can easily lead to high day-time (lights on) temps and comparatively low night-time temps; the exact opposite of what you want for good short stocky growth. Tight environmental control can help prevent overcrowding. Having a small or zero temperature difference (dif) between day and night will keep plants short.
Simon: Nobody said getting bigger yields was easy Ian, unless you believe the less scrupulous nutrient manufacturers who just want to sell you three different bloom boosters and nineteen bottles of supplements.
Ian: That’s a whole ‘nother story! The only real advantage of vertical growing, as far as I see it, is a saving on floor space. Similar yields can be achieved with horizontal gardens with the same amount of light, and a lot fewer plants. It maybe true that once completely dialed in, the increased lighting efficiency can help increase yields, but certainly not by double as I have seen in some marketing literature for vertical grow systems. I would rather use an extra light and a few extra plants in a horizontal garden, than go vertical.