While keeping proper levels of pH and changing the reservoir water regularly, having the right atmospheric conditions in your growing room can have a tremendous impact on the quality and quanity of the finished crop. Mastering the subtle environmental factors is an entire art on its own and getting everything right can lead to a significant increase in growth and yield over the course of plant’s life cycle.

The two main atmospheric conditions of an indoor garden, people are reffereing to are temperature and humidity. Even though having proper humidity levels in your indoor garden is an essential part of growing crops, I will focus on temperature which plays a vital role at how your plants process light and intake water and nutrients.

With that being said temperature affects a plan’s ability to photosynthesize and also plays a huge role in how the seeds germinate and later on fruit and flower. If the temperature falls belows the optimal range, your garden will become less efficient and produce smaller crops with lower yield.

How To Maintain A Consistent Temperature

Having a consistent and unfirom temperature in your grow room is one of the most important things a grower can do and plays a huge role in how your garden will perform. Uniform temperature is when the temperature in your grow room is the same in all areas without exceptions.

If you are using high-intensity lighting equipment in your growroom that can produce excess heat from one focal point. If it’s left not addressed the temperature around the light source will be much warmer than in the other areas of the grow room, dirupting the uniform temperature you are trying to achieve.

In order to main the uniform temperature you will have to create a adequate air flow in the grow room. Having oscillating fans (Aff.link) will lead to a continious air moving around the room so the excess heated air underneath the light fixtures will mix with the cooler air in the room.

Plants love consistency and having a consisent

temperature in the optimal range will make your plants respond well to it. The better you are able to maintain consisent temperature range, the better your yield will be over the course of the season.

In order to achieve a high level of consisentcy you will need a climate controller with ventilation fans or an air conditioner. If you want to achieve the ultimate control over your temperature, having air conditioners is a must for every grower. You will have to get a mini-split air conditioner (Aff.link) to maximize the control over temperature consistency. If you are willing to invest in a properly sized mini-split air conditioner will enjoy the luxury of pushing a single button and have absolute control over the temperature in the grow room.

What’s The Optimal Temperature Range For Indoor Gardens?

Knowing your garden’s optimal temperature range is key to achieving a maximum efficiency which is the temperature plant growth is at its peak. The optimal temperature range, depends heavily on the crops you are growing because each plant reacts differently to temperature.

Most of the fast-growing annuals , a good initial range to keep in your garden is around 70-80°F or 21.1-26.6°C. Keep in mind that most varieties will respons better at the upper end of this range. You can use this temperature range when the plant it’s in vegetative stage and fruiting/flowering stage.

If you have a climate-controlled grow room you can use the temperature range listed above as a starting point when you are trying to figure out the optimal operating temperature range for your garden.

Keep in mind that when you are experimenting with the temperature this might have an effect on the root mass. Also if your plants are grown in hydroponic systems or planting containers, the plant’s roots are more affected by the changes in air temperature than plants planted directly into the ground.

Having a climate-controlled room will allow you to set up an experiment to find the ideal temperature range by slowing increasing the temperature and monitoring the vegetative growth of your plants. Doing this will let you determine the most optimal temperature range as your plant’s growth correlates directly to temperature changes.

Different varieties of the same plant will have different optimal temperatures. If you have multiple plant varieties growing in your garden you will have to go for a happy medium in temperature range to keep all plant varieties as content as possible. The ideal temperature range for most of the plants during their vegetative growth will also be the same range for their fruiting rnge. However keep in mind that some plant varieties might prefer slightly cooler temperatures for flowering.

For growers that are new to hydroponics or don’t have an air-conditioning system in their grow room, a fan and thermostat controller can still manage to keep the garden close to the 70-80°F / 21.1-26.6°C range. However unfortunately having temperature control will be only as good as the equipment you have, but don’t get mad if the ventilation system is not working as expected. It’s much better to do your best to maintain consistent and uniform temperatures with the equipment you have on hand and try to upgrade it as time goes on to maximize the climate control.

What Is CO2 Enrichment Inside a Sealed Grow Room?

You can increase the growth rates by enriching the garden’s environment with carbon dioxide, but to get the maximum out of it you will have to increase the room’s operating temperature. When you increase the temperature this will enable your plants to properly process the additional CO 2 in the atmosphere and result in increase of photosynthesis which will increase the plant growth.

When you are operating a garden with CO 2 levels of around 1,200-1,500 parts per million or ppm, you will have to increase the temperature range to around 80-90°F / 26.6-32.2°C. Once that is done you can slowly start increasing the temperature and monitor plant growth to find the optimal temperature for your garden.

What is Temperature Differential?

When we talk about temperature differential we are reffering to the temperature change between lights-on (daytime) and lights-off (nighttime) periods. It’s an essential part of controlling the temperature that unfortunately often gets overlooked and ignored. Once you have determinted the operating temperature you will be using for the lights-on stage you can start to determine what temperature you will need for the lights-off period.

Usually the best lights-off / daytime operating temperature on average is around 10 to 15°F (5-7°C) cooler than the lights-on operating temperature. This significant temperature drop is enough to allow a plant to go through its normal process of rest and transpiration but it’s not so significant to cause problems.

When you keep the nighttime temperature within 10 to 15°F (5-7°C) of the day time operating temperature servers as a safeguard that prevents pathogens like molds and fungi from growing. If the grow room is semi-enclosed and significant drop in temperature occurs can lead to moisture and condensation issues in the growroom and on the plants.

If this continues, over time this will evolve into a perfect environment for plant pathogens like molds and fungi to grow. The optimal operating temperature range for most indoor gardens during the daytime period is around 55-70°F /12.8-21.1°C. If you want to prevent any problems and maintain healthy growth rates, having an electric heater (Aff.link) to warm up the growroom is a must.

What Are The Best Temperatures For Clones And Seeds?

Seedlings and clones thrive on consistency just like established plants, actually most of the seed varieties will only germinate once the temperature is consistently over the seed’s threshold temperature for sprouting. Temperature range of around 60-70°F / 15.5-21.1°C is perfect for most plants, while in indoor gardens a optimal temperature range for the seedling and cloning stages is usually about 72-82°F / 22.2-27.8°C. To maintain a consisent temperature that’s warm enough to promote germination and early root development, you will have to use small electric heaters or seedling heat mats (Aff.link). Both of these are great ways to have a good uniform and consistent temperature in your grow room.

Keep in mind that every plant variety is different. When you are starting from seeds always check the seed packet for instructions. There are summer plant varieties that may require warmer temperatures for germination and cold-weather plants that can be germinated in much colder temperatures.

Finding The Ideal Temperature

As we all know every indoor garden is different there can be hundreds of different variables that affet the way your crops will perform. As a general rule of thumb most growers will start with operating temperature range of around 70-80°F / 21.1-26.6°C as a starting point, but as time goes on finding the optimal temperature for your indoor garden can only be done through trial and error. It’s hard to determine how a small change in temperature will affect the overall result until it’s time to harvest your crops.

It’s like russian roulette but with plants and the process can be a bit tedious but if you are commited enough you should have no problem documenting the temperatures and how they relate to the growth of your garden. After all finding the optimal operating range for your indoor garden will ensure consisent growth rates and repetitive harvests at the end of every season.

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