How To Grow Indoor GuidesPlanting Guide

Controlling Temperature And Humidity In Grow Tent

Did you know that you can create your own ecosystem at your home? Building an ecosystem indoors is possible if you have grow tent that can facilitate your favorite plants. Having grow tent is like having a whole garden or farm. You need to provide the necessities of your plant like water, air, and sunlight. Another thing is that you also need to control the environment inside your grow tent by maintaining the right temperature and humidity.


Depending on the stage and type of your plant, you must know what is the best temperature and humidity for a better growth. The temperature varies on time and season, but generally, daytime is hotter than night. For this reason, plants must have a maintained temperature of up to 80 degrees Fahrenheit during the day and a maximum of 60 degrees Fahrenheit at night. It is advisable to have a lower temperature at night to help the plants cool their stems and bring back the lost moisture.

🌱 Seedlings

If you have seedlings and preparing for germination, always remember that do not let your grow tent drop 50 degrees Fahrenheit or below. Seedlings are like chicken eggs that need a perfect warmth to develop fast. That is why there is an available seedling heat bed to cover your seeds with a warm temperature. But, there are also plants that need cold temperatures like carrots, leeks, evening primrose, and pansies.

🌱 Sprout

Sprouting is the next stage after seed germination. If your seeds start to have sprouted, you need to increase the temperature to a maximum of 80 degrees Fahrenheit. Maintaining this temperature will ensure the best thickness and length of the sprouts. Increasing the temperature is somewhat good if you want a faster growth but expect that the shoots will be long and thin.

🌱 Small Plant or Young Adult Plant

A small plant is where your plant starts to have stronger roots to support its growth. It is also sometimes called as a young adult plant. This plant stage needs a temperature of not exceeding 86 degrees Fahrenheit to have healthier stems. Increasing the temperature will add stress to the plant.

Some signs that you can observe if your young plant has too warm surroundings are pale green to yellow leaves, and the leaves are easy to detach from the stem and becomes brittle. While if your plant has too cold a temperature, the leaves start to turn green and you’ll notice curling up.

🌱 Adult Plant

Adult or mature plants are the last stage of a plant and get ready for flower blooms and fruit development. Likewise, it is better not to exceed 86 degrees Fahrenheit and lower the temperature below 60 degrees. Altering the temperature of a mature plant will attract heat lover or cold lover pathogens like bacteria and parasites that can be the most significant rival in receiving nourishment. As a result, flowers and fruits are damaged, and parts of the stems die slowly.


Humidity level tells how moist the air is, which is very important to plants to complete food processing. Remember that plants produce their own moisture to survive in dry seasons, so increasing the humidity level of the grow tent may drown your plant. During the germination stage, the seeds need a moist bed of soil but are not too damp. Too wet soil may develop fungus that can disrupt the growth of the roots. Therefore, it is advisable to have at least 50% of humidity to avoid having a soggy grow room.

If your plant starts to have leaves and long stems, you can increase the humidity up to 70%. The more parts that a plant has, the greater the water content it needs. But, if your plant starts to have flower buds, reduce the humidity again. Lowering the moisture will allow your flowers to bloom without fungi and bacteria disrupting their growth. Low humidity for up to 40% is ideal until the maturity stage because the scent of the fruit and flower attracts many bugs, so better not to provide those pathogens with water to drink.

Photo Credits: Pure n Natural Systems


As mentioned above, there is an optimal temperature, and level of moisture in a grow tent. Besides, controlling these two factors will profoundly affect the growth of your plant. So here are things you need to do to maintain the ideal temperature and humidity.

Lowering The Temperature and Humidity

There are plants that grow in a cool and dry environment like Echinacea, Catmint, Winterberries, and many more. So, you need to consider lowering the moisture level and temperature for them to grow.

Consider Using Fans

Because the grow tent is usually closed, the temperature increases fast. Using fans, like oscillating or clip fans, will help calm and soothe the temperature of the plants. Consider the size of your grow tent because the more significant the area, the bigger the fan you need.

Aside from oscillating fans, it is also essential to check the ventilation of your grow tent. You can install an exhaust fan to absorb the hot air while letting the fresh air inside. An exhaust fan also reduces the foul odor in your grow tent.

Install Dehumidifiers

Suppose your grow tent begins to sog because of too much moisture. In that case, dehumidifiers are one of the options to lower the humidity. However, there are plants that do not want too soggy soil beddings, especially if on the seedling stage. Remember also that plants create their own moisture, so think twice if you need to water your plants often.

Balance The Light And Water

Turning on the lights will warm the plants and can lead to producing more moisture to cool themselves. To avoid this occurrence, water the plants in your grow tents as soon as you turn on the light. This process will help the plants be cooled and will absorb the moisture faster.

Aside from this, you better have a schedule for turning on the lights. For example, it is advisable to turn it on during the night. But before doing this technique, you must know if your plants need more darkness, especially at night. Such plants that love the dark are Prayer Plant, Snake Plant, and Corn Plant.

Increasing The Temperature and Humidity

If there are plants that love the cold environments, there are also plants that can survive in hot temperatures and wet soil. Examples of these plants are Marigold, Salvia, and Cosmos. If you decide to have warm lover plants, this part is for you.

Install Thermostat

Installing a thermostat will help you regulate the temperature. For example, it has signaled to detect if your grow tent has a too low or too warm temperature. The thermostat is very helpful, especially in the winter season, and you don’t want your plants to die in freeze.

Heating Mats

Heating mats or pads work by providing warmth to your plants during the cold season. It also helps in the propagation stage, but you still need to keep an eye to avoid overheating. There are also heating mats that have heat limits. So before using it, check the entire temperature of your grow tent to know how many more degrees you need to provide your plant the ideal temperature.

Use Brighter Lights

Lightings add to the warmth of the grow tent. These lights also produce some heat that can be used in increasing the temperature of the grow tent. The bigger the lights, the greater the heat. But, you need to consider the type of lights because there are light bulbs that can sunburn your plants, especially if put directly above them.

Using UV lights can burn your plants. It is better to choose blue or red light for healthier growth. LED bulbs can be used in your grow tent that provides the needed color spectrum for your plants to grow. Using incandescent light, like what you use in the house, is not advisable.

Mix Your Plants

One thing that helps balance the moisture inside your grow tent is having adult plants and young plants together. This method will recycle the humidity produced by the mature plant. Bigger adult plants produce more water content because they breathe more to live and propagate. Then, the moisture produced will be absorbed by the young plant for the purpose of growth and germination.

Water Your Plants

The most basic way to increase the humidity is to water your plants regularly. If you notice that your plants start to dry out, it’s time to solve their thirst. If you do not have time to water them with regular gaps, you can look for automatic sprinklers or put on a damp cloth to maintain the moisture of the soil.

Another thing is that you can put humidifiers. They help the plants regain and retain the moisture they need for their growth. However, it is best to place the humidifier not too close to the plants because they can accumulate too much water and drown your plants. Better to have a foot gap between the humidifier and your plants to avoid developing fungus.


Keep in mind that regulating humidity necessitates taking into account other factors of indoor plantings, such as temperature, airflow, and lighting. A humid atmosphere is created by elevated temperatures, whereas lower temperatures make a dry environment. The temperature and relative humidity requirements at distinct phases of a plant are varied. So, before you buy a grow tent, learn about your plant’s overall needs.

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