A plant’s environment is directly linked to how well that plant can thrive — this is true for both outdoor and indoor plants. At each stage of the growth cycle, they should be grown in a particular temperature and humidity level for the best possible health and the most successful harvests.
That’s why choosing to grow plants indoors in a grow tent or or grow room is such a great option: You have complete control over their environment — for the most part, that is.
Summer can make maintaining your indoor plants a bit more difficult as temperatures often rise above the ideal conditions for your plants. Luckily, there are still ways to manage your grow room’s environment and keep your plants happy and healthy.
Table of Contents
- How to Maintain a Health Grow Room Environment During the Summer
- How How Weather Can Affect Your Grow Room
- What Are Optimal Grow Room Conditions?
In this article, we’ll go over the effects hot summer weather may have on your indoor plants if you don’t manage their grow room environment, the optimal conditions for each stage of a plant’s life, and the steps you can take to ensure they’re able to thrive.
The possibility of 100° days and humidity levels of 60 percent in the summer means you’ll have to put some extra work into managing your grow room environment to avoid wilting plants, rot, and mold. It's important to keep the following in mind when considering the ideal grow room environment:
- For the most part, your grow room should never reach a temperature in the 80s.
- The only exception to this rule is during the flowering stage if you’re supplementing with CO2.
Luckily, a grow room puts you in the position of having a lot of control over your garden’s temperature and humidity levels. Below we’ll outline a few ways to make sure the hot summer days don’t put a damper on your indoor garden.
1. Upgrade Your Airflow System
Good airflow is a vital component of a healthy indoor garden. You want to avoid still air as much as possible, so when summer comes around, it’s a good idea to upgrade your airflow system.
Ensuring your grow room is always equipped with proper airflow is the best way to regulate humidity and prevent pockets of CO2 depletion. You’ll want to install a good number of fans in your grow room to ensure air is moving steadily throughout the space.
- Active Air Heavy Duty 16" Metal Wall Mount Fan (Price: $80.96) — This is a great fan if you need a strong boost of airflow in your grow room. It has three speeds and oscillates to ensure proper air circulation.
- 6" Desk & Clip Fan (Price: $15.95) — If you just need a small increase in airflow, this small, no-frills fan should provide an adequate improvement in your grow room’s temperature.
Another good tip for airflow is to open as many passive air vents as possible in order to let warm air escape through doors and windows on your grow room or indoor grow tent. It’s also a good idea to ensure your ducting is being used to its full potential and expelling stale air with the proper duct fans.
- Yield Lab 6 Inch 440 CFM Air Duct Fan Vent System (Price: $99.95) — This powerful, efficient duct fan is a great choice for moving stale air through your grow room’s ducting system.
You may also want to consider investing in an air conditioning unit for your grow room if temperature is a huge concern, but keep in mind that it may be too powerful. Air conditioning units also tend to be pretty pricey purchases, and they’re often expensive to run, too. If you’re thinking of adding an AC unit to your indoor garden, make sure you actually need it.
2. Switch to LED Grow Lights if You’re Using HIDs
If you typically use HID grow lights such as high pressure sodium (HPS), metal halide (MH), ceramic metal halide (CMH), and double ended grow lights, you might want to consider making the switch to LEDs for the summer. LED grow lights run much cooler than HIDs, so switching your lights out could make a decent change in your grow room’s temperature.
Typically, you’d want a grow light that offers your plants all the wavelengths of light they need for vegetative growth and flower product. With LED lights, you get exactly that, as well as boosted flavors and strong root production thanks to the lights’ use of ultraviolet (UV) and infrared (IR).
It's worth noting that while LED grow lights are more expensive than HIDs, they're more cost-efficient and will lead to a lower electric bill in the long run.
- 600 Watt Advance Spectrum MAX LED Grow Light Bar (Price: $779.95) — This LED grow light offers the same light spectrum as HIDs, so it’s a great option if you want to maintain the same spectrum your current lights offer while bringing down your grow room’s temperature to ensure the health of your plants in the summer.
- S720 Advance Spectrum MAX LED Grow Light Panel (Price: $795.95) — If you’re working in a medium to medium-large grow room or grow tent, you’re going to need wider coverage. This LED light gives you solid coverage as well as all the wavelengths of light your plants need to thrive.
- S900 Advance Spectrum MAX LED Grow Light Panel (Price: $995.95) — The S900 LED has an HID equivalent wattage of 1200w (actual wattage is 605w), so you’ll get wide coverage and strong light intensity without overheating your grow room. This grow light is ideal for larger grow rooms with a lot of plants.
3. Use a Grow Room Controller
One of the greatest benefits of an indoor garden in a grow room or grow tent rather than an outdoor garden is that you have control over the environment. This is especially helpful when summer rolls around and you want to make sure your plants aren’t affected by high temperatures.
The best way to manage and control the temperature and humidity of your grow room is with a grow room controller. A controller will allow you to automate fans and air conditioning units in order to keep the environment levels exactly where you want them to be.
- iPonic 614 Environmental Controller (Price: $1,249.95) — If you’re looking for a great environmental controller that gives you full control over your grow room’s temperature, this is a solid choice. With this controller, you should have no trouble keeping your indoor garden cool.
- iPonic 624 Environmental Control (Price: $2,199.99) — This controller will allow you to control the lights, fans, air conditioning units, temperature, and humidity in your grow room, and you can even operate other custom devices. The iPonic 624 is also special because it can control two grow rooms at once from virtually anywhere.
- Autopilot Desktop CO2 Monitor & Data Logger — (Price: $119.99) — Though it’s simpler than the controllers listed above, this monitor accurately tracks the temperature, humidity, and CO2 levels in your grow room. This allows you to adjust your equipment accordingly if things get too hot in your grow space.
You should keep in mind that using environmental controllers will likely run your equipment more than you’d like to and possibly raise your electric bill in the process. However, it may all be worth it when you consider how much you’ll be affecting your plants and keeping them healthy!
4. Run Your Lights at Night Instead of During the Day
Typically, you may have your grow room running on the same schedule as nature: grow lights on during the daytime and off at night, just like the sun operates. However, since temperatures reach peaks during summer days and grow lights contribute to the heat of your garden, you may want to switch things up by running your lights at night instead.
Not only will this help keep the temperatures lower in your grow room to ensure the health of your plants since you won’t be doubling down on heat, it will also use less energy, which means a lower electricity bill! This is one of the easiest, most cost-effective ways to manage the temperature of your plants’ environment.
Summer is generally an exciting time for most: school’s out, pools open, and of course, the weather gets hot. But while warm weather may be favored by a lot of people, it can pose a threat for your indoor garden.
Here are a few dangers indoor growers should keep in mind as the hotter months of the year approach:
- Increased heat and humidity can be detrimental for the health of your plants if you don’t keep an eye on things. The most common effect of heat on plants is wilting due to loss of water, which will eventually lead to dried out leaves. Excessive heat will keep some plants (a lot of vegetables like tomatoes, peppers, and squash) from producing.
- Root rot and algae formation can be a big issue in warm environments where water is unable to evaporate. Root rot will kill your plants eventually if left untreated, so it’s best to avoid at all costs.
- Heat can affect your equipment so that it may not run as well. Since the right equipment is an essential part of any indoor grow room, equipment that’s not running properly can have a big effect on how healthy your plants are.
The best temperature and humidity level to keep your grow room at will depend on which stage of the grow cycle your plants are currently in, as each stage has slightly different ideal conditions. Growing from clones, for example, requires the highest temperatures.
Improper growing conditions could lead to a number of issues that could otherwise be easily avoided.
- Rot and Mold — It's important to keep humidity controller as too much humidity will put your plants at risk for rot and mold.
- Stunted Growth — It’s important to maintain the right environment during the vegging stage because it’s when your plants will grow their leaves and expand their roots. Failure to do so could lead to stunted plants and, even worse, halted growth.
Let's discuss the ranges of temperature and humidity you should maintain in your grow room at each stage.
- 74 to 78°F for Cloning — If you clone your plants, you likely keep them in a clone tray that rests on a heat mat during the cooler months. This is because cloning requires pretty warm temperatures. The humidity level for the cloning stage should be a high 75 to 85 percent.
- 70 to 78°F for Vegging — During the vegetative stage of the grow cycle, your garden should be at a temperature of 70 to 78°F during the daytime (or when the grow lights are on) and no more than 10 to 15 degrees cooler when the lights are off. Humidity should remain between 45 and 55 percent during this stage.
68 to 75°F for Flowering — At the flowering stage, your grow room should remain at a temperature of 68 to 75°F during the daytime. At night, it should be no more than 10 degrees cooler than this.
- If you’re using CO2, daytime temperatures can be a little higher during this stage (75 to 82°F). Humidity should remain low at 35 to 45 percent for most of this period and lowered to 30 percent a few weeks before harvest. This is when the risk of mold and rot will be high, so it’s best to stay at very low humidity levels.
Achieve Your Grow Room Goals Despite Extreme Temperatures
Hot weather in the summer doesn’t mean the plants in your grow room have to suffer. With the methods outlined here, as well as the proper equipment, you’ll be able to keep your grow room running cooler even if the weather outside is hot.
So when summer rolls around and we start to reach peak temperatures for the year, don’t stress. While heat and humidity can have negative effects on your plants, you can avoid these risks by taking measures to manage the environment of your grow room.
As long as you ensure great airflow, try a few simple steps to keep temperatures as low as possible, and exercise control in your grow room, your plants are sure to survive the summer!