Why and How To Clean Your Cannabis Grow Room

Cultivating cannabis indoors gives you increased control over your growing environment. In this setting, you are able to tightly regulate water, light, nutrients, and even carbon dioxide. An indoor setting also offers your plants increased protection against pests and disease. By keeping every aspect of your cultivation space clean, you’ll stay organized and minimise the risk of pathogens and pests reducing yields or even killing your plants.

Why It’s Important To Clean Your Grow Tent or Room

The cleaner your grow room, the lower the chances of facing pesky pests, pathogens, and mold. Increased hygiene reduces the spread of bacteria and fungal spores that can damage cannabis roots, leaves, and flowers.

Paying extra attention when introducing plants and other objects into your growing space can help to keep pests. While beneficial insects are a welcome sight, pest insects can quickly lay waste to leaves, stems, buds, and branches.

Ultimately, keeping things clean will benefit plant health and yields. Any disease, mold, or pest has the potential to throw a spanner in the works. You’ll have to spend time and effort eradicating them when they set in, and any major damage will stunt growth and possibly impact your harvest.

Best Practice: Clean Before You Grow

Starting out with a clean grow tent or room will drastically reduce the chances of pest and pathogen problems. Prevention is always superior to a cure. Before getting your grow room going again, it helps to give it a thorough clean between each growing cycle.

Of course, this becomes much more crucial if you’ve just spent weeks dealing with pests and pathogens. However, a deep clean will help to minimise any risk, even if your tent is fresh out of the box.

• Cleaning a New Grow Tent

A brief clean-up will do the job in new tents or older tents that never experienced any pests or mold issues. Simply wipe down the ceiling and walls with anti-bacterial wipes and give the floor a good sweep.

• Cleaning an Affected Grow Tent

If you experienced pathogen and pest problems during the previous growing cycle, you need to take more drastic measures before starting a new indoor crop. As opposed to a light clean, you’ll need to fully disinfect your growing space.

Spores, viruses, and bacteria are microscopic and can cling to surfaces that look squeaky clean to the naked eye. Take action now to save yourself a lot of potential trouble later on. Use the options below to start your next generation of plants on a clean slate.

- Bleach

Bleach takes no mercy when it comes to microbes. This potent alkaline solution works as an effective disinfectant capable of wiping out bacteria, fungi, and viruses. Make sure to wear gloves when applying bleach. Also, consider wearing eye protection, especially when applying overhead.

Mix 1 tablespoon of bleach into 0 gallon (~3.79 litres) of water. Give it a mix and apply it to all of your grow tent surfaces using a sponge or cloth. Allow the surface to remain wet for a couple of minutes while the bleach kills off any microbes before drying all of the surfaces with a towel.

- Hydrogen Peroxide

Hydrogen peroxide also lays waste to germs. Even at a concentration of 3%, as found in most solutions available from stores, this substance can wipe out infectious microbes. Use a cloth to wipe down all of your tent surfaces with this non-toxic disinfectant.

- Drop a Bomb

Insect bombs help to remove any traces of insects from your growing room. They are especially useful if you suffered badly from pests during your last grow. Simply remove the lid from an insect bomb to purge out any insects, mites, or other pests.

How To Maintain a Clean Grow Room

At this point, your room should look as clean as a whistle. But you’ll need to maintain a high level of cleanliness going forward. Things start to get messy, fast. Introducing soil, plants, and other objects into your grow room carries the risk of importing insects, their eggs, bacteria, and fungal spores.

• Routine Cleaning

Keep organic material such as soil and plant matter off your floor and tables. These provide good shelter for detrimental critters. We recommended a Store-Vac when it comes to vacuuming your growing space. These devices feature a high-efficiency particulate absorbing (HEPA) filter that captures fungal spores and bacteria, preventing them from re-entering your space once sucked up.

• Integrated Pest Management

Integrated pest management (IPM) takes a sustainable approach to dealing with grazing insects. Many growers introduce companion plants, cover crops, and even beneficial insects into their grow rooms to help to deal with pests without the use of harmful chemicals.

Common examples of IPM include:

• Soapy water against aphids
• Ladybug larvae against mites
• Crimson clover cover crop against fungal diseases and parasitic nematodes
• Neem oil as a natural pesticide

• Caring for Clones

Clones are a great way to bypass germination and get things moving faster. However, you need to keep an eye out for unwanted passengers. You should play the role of a customs officer with every cutting that enters your grow tent. Inspect each clone before bringing it into your grow room. It’s not uncommon to find aphids, mites, and other critters hiding under the leaves or nestled by the nodes. Scrape away any pests hitching a ride before transplanting clones.

• Post-Harvest Cleaning

Harvesting is a messy business. As you cut, chop, and trim your buds, you’ll likely litter the floor with soil, sugar leaves, and stems. Make sure you sweep up all of this debris after harvest time. Insects are attracted to plant matter and organic material as shelter, whereas fungi and bacteria feast on them and multiply.

• Ensure a Clean Growing Medium

Your growing medium is a double-edged sword. On one hand, it is the source of nutrients and beneficial microbial life. On the other, it can harbour diseases and pests that make it hard for cannabis plants to thrive. There are several approaches you can take when it comes to dealing with your growing medium at the end of a cycle:

• Throw it away: To completely avoid exposing the next cycle of plants to the same pests and diseases, many growers throw their soil away. If you struggled with fungus gnats, parasitic nematodes, or other soil-dwelling pests or diseases, discard your soil and start anew.
• Reuse it: If you made it through the last grow with no pest issues, you can reuse your soil. You’ll need to add some organic matter, such as compost, green manure, or worm castings, to replace some of the nutrients and feed the beneficial microbes. Let the life in the soil break down this good stuff over 2–3 weeks before transplanting into your amended medium.
• Clean infected soil: If, for whatever reason, you can’t access new soil, but your plants suffered from a disease or pest infestation, you can attempt to clean your old growing medium. You can pasteurise your old soil in the sun to kill off bad microbes, or saturate it with enzymes that speed up the decomposition of decaying organic matter.

• Provide Sufficient Airflow

Airflow serves as a key weapon against mold formation. Fungi thrive in moist and humid environments with stagnant airflow. You can decrease the chance of mold formation by using fans to keep the air moving around your grow room.

Defoliating enables flowing air to move through your canopies more efficiently and minimises mold risk during flowering. A ventilation system consisting of an intake and exhaust will also ensure a fresh supply of carbon dioxide.

Just as the quantity of airflow matters, so does the quality. Some growers (who have the resources to invest) take things a step further with air sanitisers. These units are fitted with filters that prevent spores, bacteria, viruses, and pests from entering the growing space via the air intake. After fully sanitising your space, these devices will help to keep them as clean as possible.

You can also purchase a free-standing air purifier for your grow room. Although pricey, they are highly effective at removing pathogen particles from the air.

Daily Grow Room Maintenance

Growing cannabis offers daily moments of joy. After a long day of work, nothing quite settles the soul like grabbing a cup of tea and heading to your grow tent. Use this meditative time as an opportunity to upkeep your space. Cleaning your grow tent a little bit each day helps to decrease the risk of pest and pathogen infestation, and works much more effectively than letting everything build up over a week or two.

• Closely Inspect Your Plants and Maintain Their Condition

As you make your way around the grow space, take a close look at all of your plants. Run your eyes up the stems, along the branches, under the leaves, and around the flowers. Thoroughly scanning each plant like this can help you detect signs of disease or pests that you’d otherwise miss. As you might imagine, a magnifying glass can be of great assistance here.

If you spot anything during your rounds, make an effort to clean it up straight away. Consider what will attract pests and disease, and fix it up as you go. Prune away dying leaves, and clean up soil spills, dust, and debris from tables and trays.

• Practise Good Housekeeping

After you’ve inspected individual plants, turn your attention to the grow room as a whole. Sweep the floor of dirt and dust the corners. Eliminating potential pest habitats each day works as a simple but effective prevention strategy.

Weekly Grow Room Cleaning

Weekly cleaning of your grow room or tent consists of more thorough tasks that take a while longer to complete. You don’t need to conduct them every day, but they serve as a vital part of a grow room hygiene regimen.

• Clean Equipment and Trays

Give your equipment, tools, and trays a wipe-down once every week. Use a small cloth and a 3% hydrogen peroxide solution and wipe down all of these surfaces to kill off any lingering pathogens. Pay special attention to any tools that you might have brought in from the garden and forgotten to clean—these are potential vectors of fungal and bacterial transmission.

• Sterilise Water Systems

Hydro growers sometimes fall into the trap of thinking a lack of soil means no pests or diseases. However, bacteria and mold can still grow within tubes and reservoirs, and some species really value the dampness. Drain, clean, and sterilise your system with a diluted bleach solution once per week to prevent mold and algae from establishing a foothold.

• Check Air Filters

If you decide to invest in an air filtration system, you’ll need to check it weekly to ensure things are running correctly. Look out for any signs of wear and tear that might allow spores, bacteria, and pests to bypass your filter and enter the growing space. Replace your filters if you detect any entry points, or when they pass their capacity (usually between 6–12 months).

• Inspect Walls and Reflectors

Check behind the reflective surfaces on your tent walls. These areas can trap stagnant air and humidity, and serve as a breeding ground for mold. If you find any funky fungi, wipe them down with hydrogen peroxide. You can also wipe these surfaces down weekly as a preventive measure, even if you find them "clean" at the time.

Monthly Cleaning Tasks for Your Grow Room

Now that you have your daily and weekly cleaning lists compiled, add the following two tasks to your monthly schedule. Although you don’t need to carry these out too frequently, they are still important enough to set aside time for each month.

• Clean Light Sources

Many indoor growers neglect their lights when cleaning their grow space. However, light covers, bulbs, and even strings can collect dust and serve as potential hiding places for spores and mites. Dismantle them once a month, during the “off” cycle, and give them a thorough wiping.

• Clean Up Irrigation System

If you made the wise choice to automate your watering, you’ll need to check on your irrigation system. Bacteria and mold can build up in the dark and humid pipes. Use a pipe brush to scrub away any biofilm, followed by a flow of diluted bleach.

• Sterilise Everything

By carrying out your daily and weekly chores, you’ll likely go over every surface, tool, tray, and inch of the floor. However, by setting aside a couple of hours each month, you can make it a habit to sterilise absolutely everything. This way, if you missed anything during your other checks, you’ll hit it during this intentionally thorough monthly session.

How To Clean a Grow Tent (From Top to Bottom)

During your “sterilise everything” session, it helps to have a list together to make sure you hit everything. This way, no single spore, bacterial cell, or insect egg stands a chance.

• Clean From the Top Down

Start from the ceiling and work your way down to the floor. If you start low and work high, you’ll only knock down debris and particles onto an already clean floor. Begin by dusting the ceiling, then the walls, and then sweep the floor. After dusting, use bleach or hydrogen peroxide to wipe out anything left over. Start from the ceiling and proceed in the same order as before.

• Choose the Right Weapon Against the Right Pest

In order to remedy any problems, you need to know what you’re up against. Use an identification guide to help you know your enemy and take the correct measures.

Check out some of the most common pests and pathogens, and their remedies (including beneficial insects and companion plants) below:

• Aphids: Ladybugs and larvae, nematodes, nasturtiums as a companion plant
• Spider mites: Ladybugs, parasitic mites, neem oil
• Fungus gnats: Flytraps, nematodes, peroxide solution
• Leaf miners: Remove infested leaves, use sticky traps, neem oil
• Powdery mildew: Neem oil, sesame oil, milk spray
• Septoria: Remove affected foliage, improve air circulation, mulch soil, neem oil

Cleaning a Grow Tent: Organization Is Key

Organization forms the foundation of grow room hygiene and pest and pathogen prevention. Follow these tips to stay on top of things:

• Stick to your daily, weekly, and monthly cleaning routine to ensure the best prevention possible.
• Keep your pots well-spaced-out and accessible to reach to make daily inspection easier and less cramped.
• Keep all of your cleaning supplies in a box and place them close to your grow tent.
• Draw up a daily grow room checklist on some paper or a whiteboard so you don’t miss out on important tasks.