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1. How to Deal with Damping Off Cannabis Plants

When damping off hits cannabis seedlings, you should act as fast as possible, read on below to get all the information you need. Dealing with damping-off is important for maintaining healthy cannabis seedlings.

You’ve just received fresh cannabis seeds and can’t wait to grow. In a cup or Jiffy Pellet, you watch as the seedling breaches its shell and begin to rise towards the sun; you are ecstatic! The seedling’s first pair of tiny leaves unfold before your eyes. Everything seems to be going OK so far. When you go to check on your new green companion a few days later, you discover that it has sagged. Your efforts to revitalize the plant are futile; you have tried everything, from watering more often to delivering the “special nutrients,” but to no avail. You are perplexed when your seedling perished unexpectedly. What were the chances of this happening?

What is damping off?

Cannabis plants that have been affected by specific forms of fungus, known as damping off, die. Non-sterile soils and growth media may include fungi like Fusarium, Pythium and Botrytis. To prevent nutrients from reaching the higher sections of a seedling, they target freshly emerged seeds and seedlings. As a result, the stems soften and rot in the soil. If you constantly water plants, they will ultimately fall over and die.

Signs of damping-off

Even if you’re careful, damping-off seedlings may occur rapidly. A seedling may change from seeming healthy to dying in a matter of hours. The fungus has already attacked your plant, and there is no way to reverse the damage it has already done. However, you can learn to recognize the symptoms of a damping-off seedling to avoid them in the future.

Tiny white dots appear at the base of the stem, just above the soil line, as a symptom of damping-off. The branch will seem weak and slender in the same spot, with a deeper shade. A seedling that exhibits these symptoms, yet is still standing, is on the verge of falling over.

You may want to keep an eye out for small gnat-like creatures known as “fungus gnats” which arise when the moisture and humidity levels in your home rise. Gnats are an indication that something is amiss in your growing environment, so don’t worry too much about getting rid of them. In time, when soil moisture levels return to normal, so will the gnats.

What is the best way to stop damping-off?

There is little you can do to save a seedling damping-off if it has already fallen over. If you want to avoid the spread of illness, it is essential to remove the seedling and its cup as soon as possible.

Cannabis seedling
Cannabis seedling showing cotyledons and seed husk

Even if your seedlings are still standing erect, damping-off is likely to impact them, even if one of them has already perished. Applying hydrogen peroxide as a last resort may help halt the fungus spread. Spray each seedling’s soil with around 1ml (20 drops) with 3% strong peroxide. The peroxide will kill the fungus. With hydrogen peroxide damping off, if the illness has advanced pretty far, there is no certainty that this will rescue your seedlings. You must understand how to avoid a recurrence of this problem.

How to prevent cannabis damping off

So can damping-off be reversed? There’s not much you can do if your cannabis seedlings show signs of damping off. However, you have the power to stop this serious issue in its tracks. Please take a look at these pointers to stop cannabis damping-off in its tracks.

Make sure there’s enough drainage

With light, well-aerated soils, you can avoid damping-off in cannabis produced outdoors. You can improve drainage by adding perlite or vermiculite into an outdoor soil mix during exceptionally wet weather. Soil with high water content is more likely to become oversaturated.

Light up the room with bright bulbs

The use of solid lighting may thwart cannabis seedling damping off indoors. Seedlings should be planted no deeper than an inch into the growth medium. Consider utilizing high-intensity discharge (HID) lights or high-output (HO) fluorescent lights since they are the most efficient and brightest. Take note of your seedling light schedule to avoid complications.

Stay away from watering your plants too much

Damping-off in cannabis saplings is often caused by overwatering. This is a simple one: remember that little water is more. It’s best to water your plants just when the top layer of soil feels dry to the touch. Otherwise, the growth media may become too wet, producing the ideal conditions for damping off to take hold.

Regulate the humidity and temperature

When it comes to avoiding damping off, every plant’s developing environment component matters. It includes controlling humidity and temperature. Keep the temperature in the 70-85°F (21-29°C) range while growing cannabis indoors. You should invest in a hygrometer for your grow tent to monitor humidity levels and maintain them between 40 and 50 percent at all times. Temperature and pH stability are dependent on proper ventilation!

Keep it sterile

If you want healthy cannabis seedlings, you should maintain a sterile growth environment. You should use soil uncontaminated with bacteria or other microorganisms for seed sprouting. It’s best to start a fresh grow using clean soil rather than reusing any form of growth media.

However, it’s not only the dirt that has to be cleaned! Before reusing any growing equipment, including pots and tools, you should disinfect them with bleach and water.

Don’t rush the nutrients

Refrain from fertilizing your plants too soon! Early on, your cannabis seedlings don’t need any more nutrients. Root development is critical at this point in the plant’s life cycle. Excessive nutrition intake may harm its growth. Please don’t give your plants any nourishment until they get their first set of true leaves. Using a pH meter is a good idea.

Quality seeds are crucial for quality harvests, too

Thanks to the above advice, you will protect your cannabis plants against damping-off from seed to harvest. If you want to guarantee that your seeds are safe and disease-free, getting them from a reputable seed bank is preferable.

Picture of Ed Rushford

Ed Rushford

Ed Rushford’s impact on cannabis growing is undeniable. Though he tends to focus primarily on 2 areas, plant training techniques and dealing with disease, pests, and other problems, he has offered many insights into how cannabis plants live and grow. That’s not to say that Ed is unfamiliar with the complete life cycle of cannabis, from seed to harvest, but he uses his widespread knowledge to hone in on the minutia and niche areas of growing cannabis. Ed’s goal is to spread knowledge and allow for everyone to become better growers. 𝕏

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