South Florida. Photo of tree that I can't identify. It's been raining heavily for twelve hours and this white foam has appeared on the trunk, possibly due to water dripping. What is this foam?

I've lived with this tree for 2 years and have never seen it happen before. It is not there today now that it's dry. I observed a piece of bark overhanging the area, channeling water to drip infrequently at the top portion of the bubbles, likely creating them somehow. These do not appear to be eggs or a fungus. When I hit them with a stick, they pop. Has less the consistency of spittle bubbles; more like soap bubbles. I do not use soap or detergent on my trees.

Full tree, foam to the left of the lawn gnome

Full tree, foam to the left of the lawn gnome

Closeup of foam

Closeup of foam

  • You might also have amphibians laying eggs - i.e. breeding tree fogs, etc. - particularly if you only notice it in the springtime. Some of the egg masses can be quite a foamy slime (though typically they are aiming for a pond/pool/puddle below rather than just dumping them down the tree.) – Ecnerwal Apr 23 '17 at 19:16
  • These are pretty clear bubbles... – JoshDM Apr 23 '17 at 19:43

If this foam has appeared only during the heavy rain you've been experiencing, its a natural phenomenon. It occurs because some trees contain chemicals in the bark which can cause a soap like foam as the two interact, but this only occurs if the weather is very wet indeed; this phenomenon is not uncommon on pine trees in particular, but can happen with other trees.

If, though, you've noticed a particular area on the trunk foaming at other times, when it's not wet, check the area to make sure its not a slime flux, which indicates a bacterial infection. Info here http://www.wonderofeverydaynature.com/2016/03/26/155/

  • It is very wet, indubitably. Been raining since midnight Eastern Standard Time last night, and so hevaily that my inground pool level gained four inches. – JoshDM Apr 23 '17 at 18:24
  • Ah well, that's certainly wet enough! – Bamboo Apr 23 '17 at 18:30
  • Any identification on the tree and potential chemicals that it produces which might cause foaming? – JoshDM Apr 24 '17 at 21:07
  • Was looking to identify it before I went away for a few days but was unsuccessful - does it flower or fruit in any way, and can you add a better picture of the foliage? – Bamboo Apr 26 '17 at 14:20
  • There are bunches of purple berries that stain the everliving crap out of the concrete below and drop into my pool. The branches are long and soft; they can break off easily. I believe the main photo is a compressed version of the full photo. – JoshDM Apr 26 '17 at 14:35

I have seen this phenomenon on plants that were sprayed heavily with insecticidal soaps or dishsoap. I've been in rains in Florida! This could happen after spraying and the next hard rain will wash the soap off and in the type of rain you get would certainly cause this bubbles!

Did you spray those trees? Recently at all? A surfactant is used for sprayed pesticides, sort of a 'sticker'. That would cause the same effect as well.

If your trees have not been sprayed then we need to rethink this phenomenon.

  • I did not spray these trees and am leaning towards the natural phenomenon answer r. – JoshDM Apr 23 '17 at 18:21

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