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Cannabis Cultivation and Mold

Infected: The Forever Fungal Enemy of Cannabis

  • When cannabis gets old, does mold get bold?

You’ll find very little fungus on the floor of the Amazon. It’s such a heavily contested space that any fallen leaves are rapidly consumed by insects and other critters. Mold doesn’t have a chance to set in above ground.

There is a place where mold loves to grow, however, that’s on stale cannabis plants.

Here are some conditions in which mold thrives on cannabis:

  • Humidity above 50%

  • Stagnant air

  • Temperate climates

  • Indoor grows

The best way to prevent mold is to ensure proper air ventilation with temperature and humidity control.

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What does gray mold look like?

More commonly known as bud rot or stem rot, gray mold is a fungal disease classified as Botrytis cinerea.

Though it’s known as gray mold, it most often appears as a blackish or gray-brown coat of spores on the stems.

As the mold progresses, it’s known to weaken certain areas of the stem. Dimples or canker-like structures may appear that threaten the integrity of the stem.

If left untreated, the stem may either snap or die.

When found on the flower, the bud leaflets turn yellow and wither, and the pistils change to a brownish color. If left to its own devices, it may simply produce brown and black spots. Also, the buds may soon become covered in grayish silky mold that morphs into a hideous brown goo.

An indicator that a grow is infested with gray mold are single leaves that randomly dry out.

If found, cultivators must be very careful not to spread Botrytis.

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How Does Mold Infect and Spread Throughout a Cannabis Grow?

Mold spores can float in the air, attach to objects, and even ride on caterpillars.

They can be transferred by the cultivators themselves via gloves, scissors, and even their hair.

Gray mold doesn’t just attack cannabis, it attacks a wide range of plants.

As such, gray mold spores are everywhere.

So, how can you stop the unyielding growth of gray mold?

How To Prevent Gray Mold in Your Cannabis Grow

There are several ways to prevent gray mold including:

  • Starting with a clean medium that is treated either with steam or electricity

  • Maintaining clean garden tools

  • Cleaning yourself before entering your garden

  • Maximize airflow between your plants by removing some lower leaves

  • Grow disease-resistant varieties

  • Remove dead or rotting foliage

  • Water when the lights go on so the water doesn’t sit for too long in the dark

Sadly, you can’t always prevent such a ubiquitous fungus.

How To Treat Gray Mold in Your Cannabis Garden

There are three great ways to treat gray mold. They are:

  • Inorganic sprays

  • Biological compounds

  • Physical control

Inorganic sprays may consist of compounds like lime sulfur or fixed copper.

If the mold can be seen on the foliage, these sprays may help stifle the growth of gray mold.

Biological compounds, on the other hand, use life to fight life.

Suggestions of Gliocadium roseum and Trichoderma are the most commonly heard for staving off gray mold.

However, other resources recommend yeasts or the bacterium, Pseudomonas syringae, as an antidote to gray mold infection.

However, the most important defense tool is the human hand.

Alcohol-sterilized pruners are perfect for removing the infected parts of the plant. By cutting at least one inch below the gray mold, entire harvests can be easily saved.

Be sure to quarantine the infected portions, destroy them, and wash yourself and your tools after performing the job.

To ensure that any infection remains placated, some recommend raising the temperature to above 80 degrees Fahrenheit and ensuring that the humidity drops below 50%.

Tips to Harvest a Healthy Crop

Every grow operation is different, but every cultivator has a few key choices to make. If you want to maximize every harvest straight away, then:

  • Start with a purified growing medium

  • Select the healthiest seeds

  • Plan your nutrient and photoperiod schedule

  • Visually inspect your grow in the morning and in the evening

  • Avoid pesticides by employing chemical-free insect pest management

  • Water your plants with freshwater

You Can Grow Cannabis Anywhere! (Technically, not Legally)

You’re probably not growing your cannabis on the floor of the Amazon.

Wherever you’re growing it, keep an eye out for the growth of mold and remember this guide to help you take care of it.

If you found this information useful, please share it with your friends!

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