Greenhouse Control Systems – the Hardest Workers in Horticulture

ChatGPT Image Mar 11 2026 03 16 14 PMSometimes greenhouse automation doesn’t feel like making plants: it’s more like making music. You’re the conductor of a large orchestra, producing melodious outcomes from a diverse team. Whether they’re plucking at strings, blowing on flutes, or that lonely person who tings a triangle, every part of the ensemble knows its place.

But the difference between a beautiful symphony and a hideous ear-splitting wail depends on everything happening in the right way, at the right time. Timing. Intensity. Speed. Rhythm.

And that’s the job of greenhouse systems integration – the control technology and physical interventions that get the job of horticulture done.

In our first blog on this topic, we explored the benefits of a software “orchestration layer” in the cloud. In the second, we looked at what feeds that layer: data. In this – our third article – you’ll get up close and personal with the devices closest to that data: the greenhouse control systems.

If you’re in horticulture, you’re probably using one or more of these technologies already. But if you’re looking to expand your operation or improve your business, perhaps the list below will give you some ideas for what you could do next. And of course ICT Strypes is here to help.

Complex on the surface, simple at the core

A large greenhouse operation can contain thousands of networked devices for irrigation, humidity, temperature control, and so on. But when you zoom in, you’ll find each individual device often does a single, specific job.

A motorised blind acts on one data point: whether a plant needs shading. A vent louvre opens if greater airflow is needed. A pH sensor measures soil acidity. And so on.

These chunks of hardware fall into four broad types, each adding further capabilities to the tech stack. Let’s look at each.

1. Environmental monitoring sensors: horticulture’s eyes and ears

The start of smart greenhouse technology is atmospheric sensors, often fixed to the greenhouse frame above a planting area or pole-mounted in the bed itself. These devices collect real-time data on growing conditions, enabling managers (or applications) to optimise yields while minimizing resource waste. Some horticulture operations run perfectly well with just one or two of these – their use predates the IoT (Internet of Things) by many decades. But most would benefit from more of them – they’re the core of successful horticulture. Varieties include:
  • Air temperature and relative humidity probes, to measure the microclimate’s atmospheric heat and moisture levels – often combined in a single unit. While many plants can grow in a range of conditions, horticulturalists are looking to optimise metrics – the big one being Vapor Pressure Deficit (VPD) which indicates how well a plant “breathes” (known as the transpiration rate).
  • Photosynthetic Active Radiation (PAR) sensors measure the light available for the basic plant growth process, photosynthesis. If it’s too high or low, shading or supplemental lighting swings into action to keep your plants in a state of sunny happiness.
  • Carbon dioxide (CO2) monitors measure atmospheric carbon concentration, in parts per million (ppm). Advanced greenhouses often pump in extra CO2 to enhance growth – but since it’s a costly input, precise dosing is essential to maximise returns.
  • Leaf wetness sensors detect moisture accumulation on plant surfaces. It may sound abstract, but greenery is prone to fungal diseases in warm and wet environments, so ventilation and airdrying systems are a part of many horticultural operations.
  • Light intensity meters provide information about visible light (mainly sunlight) for general monitoring. They’re distinct from PAR sensors, which are specific to plant biology.

Sensors like these are the orchestra’s front row: obvious and visible, each providing a specific data stream vital for effective growth. If you have no other smart monitoring technology in your greenhouse – start with these.

2. Substrate and root zone sensors: digging data from the deep

As you’d expect, it doesn’t end there. Greenhouse systems integration also looks below the surface – keeping watch on the material the plant grows in. And with the diversity of modern horticulture, that’s not always soil. Fast-growing leafy greens, aromatic herbs, and high-value fruit crops often make use of exotic hydroponic substrates; others use coco coir, peat moss, pine bark, or rockwool to anchor roots and surround them with nutrients. But conditions still need to be optimised – and that means data must be collected. That’s the job of “hidden” sensors at the root level. Some are:
  • Volumetric Water Content (VWC) probes measure the percentage of H2O within the growing medium, avoiding waterlogging that leads to root rot and triggering watering only when specific thresholds are met.
  • While plants aren’t powered (!) electrical conductivity sensors measure the concentration of dissolved salts in the substrate solution (whether that’s soil or something more specialised). It’s a proxy for nutrient levels: too much or too little leads to overfeeding and death.
  • pH probes complement electrical sensors: they determine the acidity or alkalinity of water in the root zone. Maintaining pH within the right range means nutrients will be properly absorbed by each plant, making sure feed isn’t wasted.

Root sensors may do their work underground, but their effect on the business is clear as day, providing information in real-time that’d otherwise need constant sampling and testing. Together with other sensors, they complete the picture of irrigation efficiency: keeping plants healthy both above and below.

3. Actuation hardware: getting physical with growing plants

Actuators perform physical work, based on instructions from control software – which in turn is receiving data from sensors. They form the feedback loop in smart greenhouse technology: make a change, measure the results, make another change when needed. While actuators can be simple machines too, they’re often highly engineered to work in the unfriendly warmth and wetness of a greenhouse. Such devices can be expensive to install, so must work flawlessly for years. Some examples:
  • Ventilation motors. Electric motors open and close roof vents or side louvres to let in outside air, typically measured by airflow rates. (Perfectly still air isn’t a positive for many plants; they like natural breeze.) Controlling these mean temperature, humidity, and air volumes (which affect CO2 levels) can be increased or decreased.
  • Curtain drives deploy shade screens or thermal blankets on the inside of a greenhouse pane, often set up to reduce heat load in summer or retain warmth in winter. Using them effectively is what gives horticulture its longer growing seasons than outdoor farming.
  • Solenoid valves and dosing pumps. Solenoid valves control water flow, making sure plants are watered at the right rate, while dosing pumps inject nutrients and fertilisers into the irrigation line to boost growth. Being able to customise these rates allows many plants to share the same greenhouse.
  • Fogging systems are high-pressure nozzles that create mist to increase humidity or cool the air through evaporation. A large agricultural IoT system may have many kilometres of pipework handling these flows.

Actuation hardware has transformed the smart greenhouse, making sure information isn’t only collected but acted on automatically. It’s like having a team of tiny employees working in your greenhouse 24/7. Now on to the last layer: the infrastructure that holds all these sensors, meters, motors, and pumps together.

4. Top of the tech stack: data acquisition and connectivity

No device operates alone. Where a sensor reports data to, how an actuator gets the signal to start work – that’s the job of other hardware that connects to data storage, cloud applications, and other software. It’s equivalent to your home Wifi router: a vital connection between where the data sits and where the work is done.

  • Programmable logic controllers (PLCs) are found everywhere in the global economy. They’re industrial computers, often hardened against hostile conditions, that process sensor inputs and control actuators locally before sending data to the cloud. Think of them as branch offices making decisions locally without the need to involve Head Office.
  • IoT gateways aggregate data from various sensors using protocols such as LoRaWAN, Zigbee, or NB-IoT. The gateways convert this data into a format understood by other software – often standard data formats like XML.
  • Like PLCs, Edge Computing Units process data locally – but they often take in data from outside the greenhouse, like weather reports and critical storm warnings. This means business-critical risks – like a sudden overnight freeze – can be prepared for immediately without waiting for cloud processing or human decisionmaking.


These devices are the difference between an operation that manages reactively – responding to events as they happen – and one with proactive control systems, where even rare and risky events are managed with a plan prepared ahead of time. PLCs, the IoT, and ECUs bridge the gap between sensors in the greenhouse and Controlled Environment Agriculture (CEA) software in the farm office, providing the last piece of the hardware puzzle.

How Smart Greenhouses Work From Sensors to Software

CONCLUSION: Four technology layers, all conditions covered

Sensors collecting data, above and below ground. Motors and pumps making use of that data to keep your plants healthy. And logic and control hardware overseeing local conditions without the need to check every action with a distant supervisor. This is how the different parts of your “orchestra” work together – in beautiful harmony.

At ICT Strypes we work with many horticulture operations at all levels of the technology stack. And we’d like to work with you, too.

To take the first step to a more productive greenhouse, contact us here:

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