Hide this

Stopping Gray Mold On Your Hydroponics Plants

Gray mold is a fungus, just like mushrooms, but not a friendly fungus! Gray mold is a fungus, just like mushrooms, but not a friendly fungus!

Hydroponics indoor gardeners have a few enemies to worry about, and one of the most disgusting of these enemies is Botrytis Cinerea, otherwise known as gray mold. Interesting to note that this “mold” is caused by a fungus. But whatever you call it, the sight of your beautiful flowers rotting from inside is one of the truly horrific nightmares that I hope you never experience as a hydroponics grower. How can you make sure to be stopping gray mold before it starts, and what can you do if it shows up in your hydroponics grow room?

One way to block gray mold is to build a sealed grow room or retrofit your existing grow room to be a sealed room. Feel free to consult my article on building a sealed grow room. It takes some work and financial investment, but it pays off because molds, fungi, pests and other attackers can’t get at your plants. You also get the payoff of controlled climate and increased C02 levels- both of these contribute to faster growing hydroponics plants that yield more.

It’s  unlikely that you’ll be bringing gray mold into your room via clones that you purchased commercially, although it pays to carefully inspect all clones before you allow them into your hydroponics room. The reason that clones are not often a vector for gray mold is that Botrytis Cinerea usually shows up inside a big, fat flower, and clones you just purchased are not likely to have big, fat flowers.

If you were growing outdoors and had blooming plants that needed to come indoors because of too much rain or cold, those plants might vector gray mold into your hydroponics room.

Gray mold fungus is a tough organism. It can survive temperatures from about 28-90°F. It stays in a dormant state to defy eradication efforts and harsh conditions. It can travel on wind, interior moving air, tools, clothing and plant parts, and it can survive attempts to remove it via mechanical methods, such as trimming out affected plant parts.

Unfortunately, Botrytis Cinerea’s optimum temperature range for growth is 70- 77°F, which is the pretty much the ideal range for your hydroponics plants. It can tolerate temperatures below 70F better than it tolerates temperatures warmer than that.

The one good thing about ideal grow room conditions and the ideal conditions for gray mold is that gray mold prefers high humidity. If your grow room humidity is properly adjusted between 43-52% humidity, gray mold doesn’t have the high humidity conditions it loves.

This leads to another of the protective interventions you can use for stopping gray mold. Keep your room at lower humidity when your flowers are formed and dense. This might include using an air conditioner or dehumidifier.

You can also reduce the amount of water you provide your plants; overwatering during bloom phase causes your plants to transpire more water, making the interior of your flowers more sweaty so that they provide a nice place for Botrytis Cinerea. Some studies suggest that applying too much nitrogen during bloom phase assists Botrytis cinerea in its development.

Most hydroponics growers don’t foliar feed or even mist their plants after flowers are large and well-formed, and one reason is that the moisture stores in the flowers and produces a growth environment for gray mold.

Sometimes, no matter how hard you try to keep gray mold spores out of your hydroponics grow room, they will enter, and start to work destroying your crops. It’s most likely to happen during bloom phase, after your flowers are large and dense.

That’s why you should carefully examine your flowers (especially the densest ones) to look for signs of gray mold. It’s hard to detect because it starts at the inner stem and eats its way out. The main signs you’re looking for are individual, isolated flower leaves or hairs that rapidly turn brown, curl up and dry out, or a portion of a flower that turns black or grey, or becomes gooey or webby overnight. It’s ugly, and it’s scary- because gray mold undetected can rot a grow room full of flowers overnight.

When you find a telltale ruined leaf or other signs of gray mold, use tweezers or some other probing implement to peel back the outer layers of floral cluster so you can see the extent of the damage. In most cases, the moldy area will be less than 50% of the total flower mass.

Some growers try to approach this as a doctor approaches a cancer tumor- cut all of it out, and hope you got all of it, and that it doesn’t spread. Unfortunately, that hope is often futile. In fact, the safest thing you can do when you detect gray mold is remove the entire plant to another room fast. Turn all the fans off. Cut the entire affected branch or branches. Throw them in a clear alcohol such as gin or vodka for use as floral tincture. Or put them in plastic bags and dispose of them safely as soon as possible. Observe the affected plants for several days to see if mold returns. If possible, grow those plants through to harvest without allowing them to ever again be in contact with uninfected plants.

Stopping gray molds and other hydroponics plant diseases


Any time you work with a plant that has gray mold, consider it a horrible contagious enemy of your plants. Sterilize all your equipment that touches that plant. Change your clothes and shower after coming in contact with gray mold, before you go back into your grow room.

Some people advocate using fungicides or other industrial agriculture materials to spray on plants affected by gray mold. My ethics prevent me from doing that. As a preventive early in bloom cycle you can foliar spray your plants with Piranha liquid beneficial fungi. You can also use the preventives described above, with a sealed grow room being the most effective preventive. I hope you are never facing the task of stopping gray mold in your hydroponics room, but at least now you’re armed with info to help you fight back and save your plants, or at least some of them.

© Copyright RosebudMag.com, 2011

To create link towards this article on your website,
copy and paste the text below in your page.

Preview :

Powered by Rosebudmag © 2022
Follow Rosebud Magazine on Twitter Check out the Rosebud Magazine Facebook
Share this article with your friends, family and co-workers
Last modified on Friday, 21 September 2012 12:35

© Rosebud Magazine, 2010 - 2018 | All rights reserved.

Login or Register