Question
Hello sir,

I bought a Yucca plant about 2 months ago. i recently started noticing that the leaves of the plant are starting to be covered in a dust like film.. after research on the internet, it appears this is powdery mildew. Is there a quick and efficient way to get rid of this problem? One post suggests spraying the plant with Lysol daily. Is this safe? The plant looks healthy otherwise (no rotten leaves, spots etc).

Thank you!
JF

Answer
Hi Jean-Francois,

Researching on the Internet is always a crapshoot because so many amateurs are posting incorrect information, even on this website.

I am quite sure your Yucca does not have powdery mildew, but what you are seeing is a natural white film produced by the leaves to help the Yucca survive drought in its natural habitat. This film is usually spread fairly evenly over the leaves. Powdery mildew has a more fuzzy appearance and it occurs in patches. The center of those patches leaves a discolored, brownish spot on the leaf. Powder mildew is rare on Yuccas.

If, as I suspect, it is not powdery mildew, then  it is perfect okay to leave the film on your Yucca. You can wipe it off with plain soap and water on a sponge if it bothers you. Lysol or any detergent is not recommended for use on plants.

If I am wrong and you still believe you have powdery mildew based on my description, let me know and I will tell you how to treat it.

I have written articles on Yucca care that I will email for free to you (or anyone else) who emails a request to me at [email protected].

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to HorticulturalHelp.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to HorticulturalHelp.com