Return to the Azalea & Rhododendron Forum | Post a Follow-Up

Black balls stuck on leaves

Posted by dnr24 8a (My Page) on
Wed, May 5, 10 at 8:25

I was pruning my azaleas today when I discovered gall. I cut off all the branches that were infected, but I also noticed a number of leaves in an area that had small black dots or balls stuck on. I could brush them off, but was concerned that they might be a fungus, in which case, I didn't want to spread the spores. My thought is that they are caterpillar waste or something. I saw similar spots on my tomato plants when I had tomato worms. Could this be a problem pest? So far, other than the gall, the leaves look healthy.

Follow-Up Postings:

RE: Black balls stuck on leaves

  • Posted by morz8 Z8 Wa coast (My Page) on
    Wed, May 5, 10 at 12:45

Azalea leaf gall? If so, removing the galls was the right thing to do.

As for the black spots/dots, a guess without a photo but it does sound like caterpillar frass. Keep an eye on the shrubs, see if any more evidence or damage appears that would warrant treatment.

RE: Black balls stuck on leaves

Another possibility is shotgun fungus. If you have wood mulch, it can develop a fungus that shoots tar like spore cases that stick to anything they touch.

From Cornel University:

The spots may actually be spores from members of a group of fungi commonly called the "shotgun" or "artillery" fungi in the genus Sphaerobolus. These fungi colonize dung or other organic matter such as wood mulch, wood benches, wood sheds, etc.

Artillery fungi use an interesting mechanism to disperse their spores. Dark brown spore packets, called peridioles, sit on top of specialized cup-shaped cells which accumulate water and cell contents. When enough liquid is accumulated, the cupped cells invert causing the cells to burst and propel the peridioles as high as 19 feet where they can adhere to new surfaces.

RE: Black balls stuck on leaves

Hi rhodyman, I just came across your response about the little black balls and it sounds like exactly what' happening in my kitchen! I have herbs growing on my windowsill - basil, thyme, rosemary, mint and garlic chives. For the past few months I've noticed these little black balls that look like poppy seeds stuck to mostly the mint leaves (mostly on the bottom but also on top), and also all along the ceiling above the plants and on the window that the plants sit next to.

What is happening in my kitchen?!? Thank you!

RE: Black balls stuck on leaves

Danielle, that certainly sounds like artillery fungus spores! I'd dispatch those herbs to the outside and get them repotted, tout de suite!

Artillery fungus grows on old wood, such as might be in your potting soil or mulch. Other culprits could be any unpainted wooden structures. I've seen it arise on someone's wooden window frames in an old garage. Inside that garage was parked a very rare antique automobile, fully restored. The paint job was ruined.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Azalea & Rhododendron Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here