Get the Facts on Plant Environmental Factors!

Plants need a perfectly balanced grow room environment to thrive. Exposure to light, water, temperature, humidity, ventilation, and nutrition will impact plant health, canopy formation, and yields. From seed to bud, these environmental factors play a role in plant growth at every stage. In this blog, we’ll help you create a perfectly balanced environment that promote the healthiest, most productive crops.

How does light affect plant growth?

Plants depend on light for growth and development, as it’s essential for photosynthesis.

High light intensity can overwhelm your plants, causing stress, overheating, and leaf burn. On the other hand, low light can prevent optimal growth.

How do I prevent light stress and light burn in my grow room?

Plants experience light stress and light burn when exposed to excessive light levels for long periods of time. Excessive light intensity also causes light stress, oversaturation, and burning.

• Preventing Light Shock: Light shock is caused by sudden changes in light levels, preventing photosynthesis and impacting healthy growth. Following natural day and night cycles prevents light shock. In the vegetative stage, plants need at least 13 hours of light per day. For flowering, plants need longer night phases. This means 12 hours of uninterrupted darkness every day.
• Promoting Natural Development: Sunrise and sunset settings support natural photosynthetic behaviours. To prevent light shock, gradually increase light outputs instead of switching them on at full power. Also, your grow lights’ outputs should gradually decrease at the end of the day.
• Preventing Light Burn: High red light wavelengths cause excessive growth at the top of the canopy, which slows bud growth underneath. High red light burns the leaves, causing them to wilt, crisp around the edges, and preventing photosynthesis. To prevent light stress and burn, we recommend using grow lights which balance blue, green, and red outputs, such as the Telos Dynamic 930 or 1200.

How does water affect plant growth?

The amount of water your plants need depends on the grow room environment and growth stage.

• Young Plants: Seedlings and young plants only need a small amount of water, once or twice a day.
• Vegetative Growth: During the vegetative stage, we recommend using 3-6 litres of water per square metre.
• Flowering: For mature plants in bloom, watering every 2-3 days is often sufficient. Roughly 2-3 weeks before harvest, we recommend that you reduce watering frequency.

How do I regulate the water intake of my indoor crops?

• Hydroponics: With hydroponic systems, such as the Oxypot Deep Water Culture system, don’t need to manually adjust watering frequency because the plants are continuously submerged. However, regular water changes are essential to prevent salt build-up and other contaminants from harming your plants.
• Semi-hydroponics: Semi-hydroponic systems combine the benefits of hydro with media to support plant development. There are several types of semi-hydro systems. Some use a reservoir of water and nutrients below the plant pots, while others introduce water directly to the growing media. Systems such as IWS Flood & Drain result in strong root networks which absorb and retain large amounts of nutrients.
• Media-based Systems: With media-based systems, growers get the choice between hand watering or automated watering. We recommend using automated watering systems for easier and more consistent watering, promoting optimal plant health and growth. Semi-automated systems such as the IWS Autodrain Standard ensure consistent, predictable feeding cycles, encouraging stable root development, faster growth, and higher yields.

How does temperature affect plant growth?

Your grow room’s temperature affects vital processes like photosynthesis, respiration, and transpiration. Plants have specific temperature ranges for optimal growth and development at different stages, including germination, vegetative growth, and flowering. Moreover, your plants need different temperatures depending on whether it’s daytime or nighttime.

• Consistent Temperatures: Constant temperature fluctuations will shock your plants, affecting photosynthesis and respiration. A 6°C or greater drop in temperature can cause condensation in the air, which increases the risk of mould growth.
• Young Plants: For germination and seedlings, aim for daytime temperatures of 20–25°C and nighttime temperatures between 16–21°C. High temperatures stress your seedlings and stunt growth which can be fatal at this early stage.
• Vegetative Phase: For vegetative growth, daytime temperatures between 20–28°C promotes vigorous growth. Slightly lower temperatures at night also supports root development.
• Flower Phase: Ideal daytime temperatures for flowering are between 21–27°C. At nighttime, temperatures should be between 15–21°C.
• Harvest Time: Before harvesting, daytime temperatures should be reduced to between 18–24°C, and between 15–20°C at night. These temperatures before harvest boost bud development, terpene and resin production, and flavour.

How do I control temperature fluctuations in my grow room?

Heaters, humidifiers, and dehumidifiers work together to create a balanced tropical climate to allow your exotic plants to thrive.

Environmental Controllers: Installing an environmental controller is the easiest way to maintain optimal temperatures for plants. Global Air Supplies offers three different day & night controllers designed to control heaters, humidifiers, and dehumidifier units with ease.

Each controller allows you to set specific environmental settings for consistent control even when you’re not there. These controllers protect your plants around the clock, promoting consistent growth, healthy development, and bigger yields.

How does humidity affect plant growth?

When grow room humidity is too high, mould can take over your growing environment, killing your flowers, and destroying yields. Mould starts to grow when humidity reaches 55% or higher, and the ideal range for mould growth is 70% or more.

How do I prevent humidity spikes in my indoor grow room?

Your plants need different humidity levels at each growth stage.

• Seedlings & Young Plants: Seedlings need a relative humidity level between 65–70% for two to three weeks.
• Vegetative Phase: For vegetative growth, an acceptable humidity range is between 40–70%.
• Flowering Phase: Flowering plants need a humidity level between 40-50%. It is important that your grow room’s humidity level never exceeds 60% during this growth stage. To prepare flowers for harvest, grow room humidity must remain between 45%–55%. This produces high-quality buds which are free from mould and pathogens.
• Prevent Humidity Spikes: To prevent humidity spikes in your grow room, we recommend using a humidifier such as the SonicAir Humidifier Pro. This humidifier controls humidity levels in bigger grow rooms by producing large volumes of mist.
• Balance Humidity: We also recommend using a dehumidifier such as the ora Dehumidifier 60L. Pair this unit with an equally powerful humidifier to balance relative humidity in your grow room. The ora 60L Dehumidifier enhances yields and protects crops from mould and diseases caused by excessive moisture.
• Control Humidity: Keeping an eye on your grow room’s humidity is made even easier with an Air Comfort Bluetooth Temp & Humidity Sensor. Its Bluetooth technology allows you to connect the sensor to your phone. It displays temperature and humidity graphs, allowing you to monitor the environment even when you’re not in the grow room.

How does ventilation affect plant growth?

Air circulation in your grow room is vital for maintaining healthy plant growth. Ventilation helps your exotic plants transpire (or sweat). Transpiration moves water and nutrients from the soil up into branches, leaves, and flowers. The water transpired by plants naturally evaporates into the air, gradually increasing humidity.

• Mould Growth: Without proper ventilation, stale air builds up around your plants, creating a humid environment that breeds mould. Well-ventilated grow rooms prevent these stagnant zones. These are areas in the grow room where air accumulates moisture, developing mould and fungal diseases. Without fresh air, your exotic plants will die.

How do I increase ventilation in my grow room?

There are several pieces of vital equipment involved in grow room ventilation.

• Balanced Air Circulation: Intake and outtake fans work together to move air through the space. Fan speeds must be balanced to ensure enough air is being transferred in and out of the grow room. This means matching the power of your fans to the size of your grow room. If your fans are too fast, it will create an environment which is too dry. Too slow, and you won’t be able to control humidity and temperature.
• Air Exchange: Outtake fans pull old air out of your grow space. Because hot air naturally rises, the fan must be installed at the top of your grow room. Similarly, intake fans bring fresh air into the grow room, oxygenating the growing environment. The Rhino Ultra Silenced Fan can be used as either intake or outtake fans. It is specially designed to be quiet, adaptable, and powerful.
• Air Movement: Oscillating fans, such as the ora Wall Fan, are a simple and cheap method of increasing airflow around your grow room. The breeze strengthens your plants’ stems, prevents stagnant air build-up, and reduces the risk of pathogens ruining your crop.
• Air Purification: Plants naturally produce odours which you may want to control in your grow room. Installed into your ventilation ducting system, carbon filters such as the Rhino Pro Filter, capture unwanted odours. Carbon filters also absorb the terpenes given off by your plants to cleanse the air you extract from your grow room.
• Odour Control: Odour control products, such as those by OCD, also help to eliminate unwanted odours in your grow room. These products use special odour-busting technology to stop smells from coming back. When paired with your ventilation system, you get a fresh grow space protected from bacterial and fungal pathogens.

How does nutrition affect plant growth?

Proper nutrition is crucial for growing healthy, robust exotic plants, influencing both vegetative and flowering stages. Nitrogen (N), phosphorus (P), and potassium (K) play key roles in promoting vegetative growth, root development, and bud formation. Micronutrients are also essential for plant health and flavonoid production.

How do I optimise the feeding schedule for my exotic crops?

We recently published several articles as a deep dive into plant nutrition, nutrient deficiencies, and products that maintain plant health. These blogs are found here. Here are some tips for optimising your plants’ feeding:

Begin with a Base: To optimise your plants’ feeding schedule, begin with a base nutrient solution which provides plants with a balanced range of macro- and micronutrients. For example, if you’re growing in coco coir, use a specialised base nutrient such as Plant Magic Coco A & B. This two-part solution provides the building blocks for strong, fast growing plants with masses of fruit and flowers.

Feeding Frequency: Adjust feeding frequency based on growth stage and medium, and monitor plant health for signs of nutrient deficiency or excess. Each growth stage requires different doses of nutrient solution.

• Vegetative Growth: During vegetative growth, focus on nitrogen-rich nutrients for leaf and root development. Fertilise once or twice a week for standard potting mixes, or more frequently for inert mediums like rockwool. To boost your plants’ vigour and energy during this phase, we recommend House & Garden Amino Treatment. This silicon deficiency treatment contains amino acids and enzymes which stimulate vegetative and floral growth. This aids the transitional growth period to provide you with bigger and healthier plants.
• Flowering Phase: During flowering, switch to a nutrient solution high in phosphorus and potassium to support bud formation. We recommend Plant Magic PK 13/14 to boost flower production, which helps produce large and tasty yields. With this PK solution, you don’t need to use any other solutions with phosphorous and potassium.

Some growers prefer more frequent feeding (several times a day) during the mid-to-late veg and flowering stages to minimise salt buildup and nutrient lock-out.

Now you have everything you need to build a perfectly balanced environment! From systems to nutrition, our tried-and-tested solutions help you produce the biggest, healthiest crops. Explore our full range on the Global Air Supplies website.