We have a ~1 year old Rainbow Eucalyptus tree. It's now about 1 metre tall, and we've noticed a concerning 'bubbly' texture on most of its upper stems. The "bubbliness" is the same sort of hard-ness as the stems; somewhat smooth, and sort of waxy.

I could easily scrape/cut the "wax" away, in which case it initially maintained it's shape and texture. It was relatively easy to 'smush' between my fingers, at which point it felt somewhat wet and 'mushy', and had no discernable "contents".

The mid-height stems seem less affected, and the lowest seem entirely unaffected. The leaves in the crown also seem more curled than I would have expected.

  • We're in North London, UK.
  • The tree was bought in the summer.
  • The tree was outside on a South-facing Patio through to mid-October, well before it got properly cold.
  • It was then moved to a (not-really sealed or insulated) South-facing lean-to/greenhouse, which stayed above 10 C until mid-November.
  • We brought it fully inside the night before the first frost.

Images below. (click for hi-res images)

Qustion: Is our tree OK?

If not, is it save-able?

Affected Branches:

Heavily Affected branch Heavily Affected branch Lightly Affected branch

Unaffected branch

Unaffected branch

Overall tree

Overall tree

Results of scraping wax

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  • 2
    It does not look okay - not sure what all the soggy white stuff is on the stems, or at least it looks soggy - have you tried scraping some off then inspecting with a magnifying glass to see if there are any creatures or eggs or something inside?
    – Bamboo
    Commented Dec 5, 2020 at 12:03
  • Can't see in photo but it could be scale insects. Commented Dec 5, 2020 at 15:24
  • @blacksmith37 at first glance,yes, but the high resolution pictures show the deposits as being shiny, soggy or wet, not dry and fluffy... doesn't mean it isn't scale, but that's not typically how scale looks
    – Bamboo
    Commented Dec 5, 2020 at 15:39
  • @Bamboo, @blacksmith37; more detail added.
    – Brondahl
    Commented Dec 7, 2020 at 2:14
  • I could magnify the two last pictures. If I'm right, this is not one lump of some waxy material. You may have scales stacked atop each other. See if you can separate them into individual "disks". At-least that's what it seems to be from the picture. Commented Dec 7, 2020 at 9:23

1 Answer 1


We contacted the vendor and they believe that this is Oedema brought on by high-humidity (presumably from being brought inside, and perhaps by over-watering?)

We moved it to a less humid location and reduced the watering somewhat, the waxy surface gradually receded, and didn't return the next year. Success!

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