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I recently discovered upon close examination of these strange, small, brown-reddish growths on the stems of my plant (picture below). This was a recent occurrence, after I placed the plant on the windowsill in my kitchen (close to where a lot of greasy cooking occurs, unfortunately).

I was wondering if anyone happens to know what these growths are called, and if so whether they are endangering the plant. And if it is indeed harmful, how should I try to remove them and also prevent further growths?

enter image description here

Niall C.
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daspianist
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    I think this is some kind of scale but I'm not 100% sure. You can look at http://whatcom.wsu.edu/ipm/manual/blue/scale.html for more information. You'll want to be sure first but you can fight scale by carefully scrubbing it off and applying diluted soapy water to the plant. You can also treat this with commercial insecticides, I believe. – Alpar Aug 28 '14 at 07:32
  • Agree - scale infestation – Bamboo Aug 28 '14 at 10:18
  • Thanks for your expertise! This indeed appear to be the case. – daspianist Aug 28 '14 at 10:46
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    See also: http://gardening.stackexchange.com/questions/1523/what-is-this-brown-shell-like-thing-growing-on-the-stalk-of-my-avocado-plant – Niall C. Aug 28 '14 at 13:41

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Scale infestation - brown scale in fact, not that it matters. If you've got some rubbing alcohol or some methylated spirits, dip a cotton bud (Q tip) in and rub off the scale from the stems, being careful not to douse the stems or leaves in the spirit solution. The immature ones on the back of the leaves (paler, smaller) are susceptible to oil sprays such as Neem oil, or you may find you can wipe them off, so inspect all backs of leaves and stems and try to clear them all away.

UPDATE: No, not really, no prevention, just inspect the plant occasionally once you think you've got rid of them all. They can produce a lot of generations a year on houseplants, and their eggs are usually covered with a sort of white fluff (if you look closely, you can see white fluff extruding from the mature scales in the picture). The nymphs (those lighter ones on the backs of the leaves) hatch out and as they mature, attach themselves to the thicker stems, where they remain permanently. There are insecticidal sprays you can use (check what's available where you are) which might be easier for recurrent infection. Also check the pot - sometimes mature scales settle there too, on the lip of the pot and even on the outside occasionally. These can be removed with the alcohol method described above.

Bamboo
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  • Thank you for the identification and also suggestions to getting rid of it @Bamboo! A quick follow up question: is there anything I could do to prevent future infestations? I live in a highrise and most of the plants are placed on the windowsills with very little contact with ground soil, etc, so this infestation is definitely unexpected... thank you! – daspianist Aug 28 '14 at 10:55
  • @daspianist I feel a bit uncomfortable because Alpar diagnosed correctly in a comment first, but see updated answer – Bamboo Aug 28 '14 at 11:25
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    @Bamboo Don't worry about it, I wasn't sure enough about it to post an answer so it's entirely on me. You also gave more information on treatment :) – Alpar Aug 28 '14 at 17:47
  • Thank you both for your help! The original comment definitely had me looking in the right direction and this answer just solidified everything. Thank you to the both of you Alpar and Bamboo. – daspianist Aug 28 '14 at 18:00