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Ferns/macho fern


some of the leaves are black which look like mold?  I just ignore these plants but have watered more frequently as planted sod.  They grow like weeds.  What should I do for the black. brenda in Florida

Brenda hi;

Naturally, I would need to see some photos in order to correctly identify the problem (both close up and from a further view).

However, regardless of problem (mold or fungus), it is safe to assume that the change in conditions (more frequent watering), is the underlying cause.

Macho ferns should thrive and flourish in a tropical setting. They can do well in both shade and sun, and while they appreciate constant soil moisture, they do prefer for the foliage to dry out between irrigation instances.

I would not recommend a chemical intervention, as this will not deal with the underlying cause: are the plants too wet?  Are they too dark?  Has there been added shade and canopy over time as well as more frequent irrigation?

You have a couple of choices: one is to simply leave the plants alone and hope, when you start cutting back on the frequency of irrigation, that the problem is solved.

The other would be to cut back the infected fronds (as close to the ground as possible) in order to allow more light and air to filter through.  You may cut as lightly or heavily as you see fit, based on how important it is to you that the plant look full and perfect all the time.

Lastly, in some instances, the mold (possibly known as 'sooty mold') is actually a by-product that grows on the secretion of certain insect pests.  If you have any white scale-like things or small yellow bugs on the bottom of the fronds (leaves), try to send some close up pictures and I will recommend a solution.

I hope this helps.  Please do not hesitate to follow up with further question as needed.



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Dan Carmi


I can answer all types of questions regarding ferns: their physiology, life cycle, taxonomy, culture (for both the professional and hobbyist), home and garden application and care, site suitability, and more. I can also answer questions in the fields of greenhouse production, foliage plants, and houseplant care, along with questions in the general field of ornamental horticulture. I may be able to identify fern and foliage plants by photo, but I am unlikely to be able to do it by description (though I will never turn down a challenge). I am not an expert in crop, field, and agronomic production. I am not an expert on annuals, perennials, tree & shrub crops.


I am a horticulturist with a formal education and twelve years experience in commercial fern and tropical foliage production. I also served as Adjunct Professor of Horticulture at Florida Southern College.

Florida's Nursery Growers and Landscape Association: current member and Action Chapter Board Member 2006-2008.

I have a BSc in Environmental Horticulture / Business from Florida Southern College, specializing in Greenhouse Management and Production.

Awards and Honors
FNGLA Action Chapter President's Award 2006-2007, numerous academic awards 2001-2005.

Past/Present Clients
Through my place of employment, I serve hundreds of commercial growers across the country and beyond.

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