A plant tower grows the crop upwards, and this one adds the two things a tower needs to be worth running at commercial scale. The tiers rotate, so every plant spends part of the day on the light side instead of standing in the shadow of the tower above it, and the feed runs from a PLC controlled pump on a set interval rather than from a grower with a valve. Sensors in the loop hand off to dosing pumps, so the strength of the solution is corrected where it is measured. Towers are modular, with snap fit pipework and custom port spacing.
A tower uses height where a bed uses floor, which is why it suits a house with expensive square metres and a short cycle crop. What a tower does not solve on its own is evenness: the plants on the sunny face grow ahead of the plants behind them, and the feed has to be delivered to the top of a structure nobody can reach into. This build answers both.
The feed is the first half. A PLC controlled pump delivers solution on a set interval, so the tower is fed through the day without anyone standing at a valve, and the interval can be changed as the crop fills rather than being fixed at installation. Because the same controller handles the dosing, the strength of the solution is corrected against a reading rather than against a mixing schedule.
The second half is the structure. Towers are built from modular trays with snap fit pipework, so height and port spacing are set on the order, and a tower can be added to a row without a new tank or a second control point. Towers of this family sit with the rest of the hydroponics system range on this site.
Plants on a tower shade each other. The tower itself casts a shadow on the rows behind it, and within a tier the plants on the outer face intercept light the inner ones never see. Rotating the tiers slowly moves every plant through the lit side and the shaded side across the day, so the crop on a tower finishes together instead of grading itself from front to back.
Even maturity is the commercial point of it. A tower that grades its own crop has to be picked in passes, and each pass costs the same labour as the last, so the whole tower is picked later than the first plants on it were ready.
The pump runs to a set interval rather than continuously, which keeps the root zone fed without leaving it submerged. Solution is delivered down the vertical gutters to drip stakes, so each port is fed at the plant rather than flooded from the tier above. pH and EC sensors sit in the loop and call the dosing pumps when a reading drifts off its set point.
Water use is a function of the loop rather than the crop: what the plants do not take up returns to the tank, so the volume consumed is the volume that evaporates and what the crop holds. That is what makes a tower worth running where the water supply is metered or limited. A shallower tower built for lettuce and herbs is described in the 5 layer hydroponic grow tower kit page.
The table below is the standard build. Tower height, port spacing and the control package are set to the house and to the crop.
| Growing method | Vertical tower, soilless |
| Tiers | 12 tiers of growing ports, rotating |
| Feed control | PLC controlled pump on a set interval, about every 2 hours |
| Nutrient control | pH and EC sensors linked to dosing pumps |
| Emission | Vertical gutters with drip stakes at each port |
| Tomato capacity | About 8 plants per tower |
| Tower material | Food grade PVC, white |
| Wall thickness | 1.8 mm to 2.0 mm |
| Support pipes | Galvanized steel pipes |
| Construction | Modular trays with snap fit pipework |
| Water system | Recirculating; deep water culture or aquaponic loop |
| Crops | Tomato, lettuce, herbs, leafy vegetables and microgreens |
| Customisation | Tower height, port spacing and control package set to the site |
A tower is set on a level base, because the tiers stack and a tower out of plumb loads one side of the joints. The tank and the pump go in first, then the towers are built up, the snap fit pipework is run, and the controller is commissioned on a wet system so the interval and the set points are read against a working loop. Towers are laid out in rows with a working aisle, so every port can be reached at picking height.
Upkeep is the pump intake, the filters and the rotation drives. The intake is cleared on a short cycle, because a partly blocked intake drops the flow to the top tiers before anything visible changes. Rotation drives are checked for free movement at each crop change, since a tier that stops turning grows ahead on one face and behind on the other. Sensors are cleaned and calibrated on their own routine, and the tiers are washed through between crops so root material does not carry over.
Towers of this type are used for soilless tomato and pepper production where the crop is trained and picked over a long season, for lettuce and leafy vegetables on a short cycle, and for herb and microgreen programmes where the crop is cut rather than picked. They suit commercial houses adding capacity without a new building, operations where the water supply is metered or limited, and projects that want the growing system specified before the structure is built. A tower system built around the same crop on a fixed frame is described in the automated hydroponic tower system page.
Research and extension material on controlled environment horticulture is published by Cornell University. Market and sourcing information for agricultural buyers is published by Wikifarmer.
Because a tower shades itself. Turning the tiers moves every plant through the light side and the shaded side over the day, so the crop finishes together instead of the front face ripening while the back face is still filling.
A PLC controlled pump runs on a set interval, roughly every two hours, and delivers solution down the vertical gutters to a drip stake at each port. The interval is changed as the crop fills rather than fixed at installation.
The galvanized support steel is rated for 15 to 20 years under normal growing conditions. The pump, the rotation drives, the sensors and the tower panels run on their own service cycles and are replaced as they come due.
We provide a 10 year structural warranty and a 5 year anti-corrosion warranty on the galvanized steelwork. Details are set out in the contract for each project.
Send your house dimensions, the crop you plan to run and the growing layout you intend to use. We reply with a layout drawing and a full quotation.
