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I brought some trailing vinca cuttings indoors to hang around the apartment. Very pretty — but I just discovered a sticky (ew) spot on the furniture and carpet under the hanging vines.

The leaves are covered in what looks like a misting of water, but which is very sticky and saplike in consistency.

Is this normal/healthy? (With whom do I lodge a complaint about a poorly designed plant?) The plants are otherwise very happy-looking.

PS: The only information I can find about vinca sap is that it's likely poisonous. So I guess I won't lick my plant.

sappy leaf mo leaf mo good

j6m8
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  • If they're sticky, its not guttation - you say its trialing Vinca, but neither Vinca minor nor V. major have woody parts, the growth is always soft green and I'm seeing a woody stem in your image, so do you know another name for your plant? – Bamboo Jan 01 '19 at 21:57
  • Interesting @Bamboo — what in the image is woody stem? (I'm not sure about how to formally define that!) the growth in the bottom right corner is new growth and is gradually turning green, fwiw – j6m8 Jan 02 '19 at 21:36
  • The bit that's wood coloured towards the bottom right of the image...Vinca has only soft, green stems, that's why I'm not sure its actually Vinca... – Bamboo Jan 03 '19 at 01:28
  • @Bamboo just edited the post with a new picture — that section of stem is "green-ish" except at the split — but still just as soft as the rest of the tissue. – j6m8 Jan 03 '19 at 15:35
  • Guttation is exudation of xylem sap, so there is no reason why it might not be residue after drying down. Only dew (pure water) leaves no residue after drying. An important detail that might be of interest is those brown bumps on the main stem. Are they plant tissue or are they covering up some undesirable traveller? – Colin Beckingham Jan 03 '19 at 16:26
  • See new answer below....@j6m8 – Bamboo Jan 03 '19 at 17:57

2 Answers2

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Hmm, odd. There is a phenomenon called guttation which happens when the plant is in particular environmental conditions (see https://en.wikipedia.org/wiki/Guttation); this seems to fit the fact that the droplets are evenly distributed over the leaf. As an experiment, take a moist cloth and clean off one leaf only and see if the drops come back, and how quickly. Draw conclusions. Thoroughly wash disgusting cloth.

If it is guttation the issue might go away by itself as the surroundings change.

An alternative is secretions from some awful pest, but if you don't see any let's apply Occam's Razor here and go with the simplest explanation.

Complaints should probably go to the person that last watered the plant or the building superintendent. Twisting of the short hairs just above the ear and yelling is sometimes effective.

Colin Beckingham
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  • Thank you! That certainly checks out — it seems like the long hanging vines would be more likely to undergo guttation since gravity would add to their root pressure. (To wit, it was quite hard to clean off the material from the leaf, so perhaps it has already dried and I'm only now noticing!) – j6m8 Jan 01 '19 at 20:59
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Aha - that's a clearer image, and under magnification, clearly shows a scale insect infestation- that's what the brown bumps are, image/info here http://homesteadbrooklyn.com/all/2017/1/17/common-insects-pests-on-houseplants. And that will also be the cause of the sticky 'sap' you've been getting, its the honeydew from the scale insect, not guttation. If these are just loose stems you've cut for decoration, and they're not actually growing from a pot, I'd get rid of them out of the house asap if you have other plants, before they get a chance to infest any other greenery or houseplants you have indoors. If you do have other, permanent plants indoors, check them over carefully...

Bamboo
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