Robin’s pincushion.


At first glance, I thought it was some sort of strange fluffy pod, presumably left here by cute furry space aliens.

Of course, I have a very vivid imagination.

To my great disappointment, it’s a mossy rose gall.  And the funniest thing about it is that I didn’t even know a rose was growing there.  I’ve literally* walked by this particular spot on my way to work nearly every day for five years…surely you’d think I’d notice the five-and-a-half foot tall rose bush.  In my defense, it’s jammed in with a whole bunch of other grasses and shrubs, seeds randomly blown in years ago and taken hold in the midst of a dense planting of junipers that the landscapers put in nearly three decades earlier.  No one has ever pruned or removed any of the odd plantings because you can’t access them – the junipers have made an impenetrable thicket around them.   I certainly didn’t notice that the rose had bloomed this summer, but it’s chockfull of hips right now, flashes of brilliant red that catch my eye every time now that I know they’re there.   There’s a lesson here about being more observant, I can tell….

Anyway, because my knowledge is a little fuzzy (groan!) about mossy rose galls, I did some reading.  If there are any rosarians out there who can offer some more insight, please chime in – I’d love to hear from you!  Mossy rose galls are caused by a tiny wasp called Diplolepis rosae (or Diplolepis spinosa), which lay their eggs in the leaf buds of the rose in the spring.  The plant reacts to the invasion by producing a gall, which grows all summer and eventually ends up as winter protection for the wasp larvae (clever wasps, using their host like that).  The following year, up to 40 adult wasps can emerge from a single gall.  I found contradictory reports on how the galls affect the health of the rose – some say the rose is not harmed at all, while others say that the galls draw nutrients away from the rose and that if there are enough galls, the rose will die.  The only way to get rid of the galls is to prune them off in autumn, and this article points out that they can be placed in cut flower arrangements for extra interest.  (With the larvae still inside?  I’m not terribly keen on that.  Granted, the writer did make a mention that the larvae are often parasitized by other insects…but isn’t that just swapping one bug for another?  I’m not sure I want that particular kind of decoration in the house).   Mossy rose galls are most often found on wild roses (such as Rosa acicularis, which I believe is the specimen I found), and frequently rugosas.  The wasps that create them don’t go after plants other than roses.

The most interesting part of all of this is that another name for mossy rose gall is “Robin’s pincushion.”  Isn’t that an absolutely lovely term to describe a winter housing complex for tiny slimy wasp-babies?

*You may have read that the word “literally” has been officially granted an additional definition, which contradicts the old one but supposedly has validity because of the rampant abuse – I mean, informal usage – of the true meaning over the years.   I’d like to say that I’m literally giddy about how the English language is evolving, but I know I’ve literally misused the word a million times over the years.   😉

Have your roses ever literally (I can’t help myself) been plagued with mossy rose galls or crown galls?

UPDATE (as of September 19, 2013) – There is a great article on Wikipedia about mossy rose galls – it’s well worth checking it out to find out more information about the wasps that cause them.  There are also some very interesting medicinal uses (a cure for baldness, anyone?) and historical tidbits listed…plus, some excellent photos.  Please link here.


  1. How I like your vivid imagination! And I literarily think it is OK to use the English language creatively;0) Ha, with my English as second language and not being bothered at all with my own let alone other people mistakes,I really think it is all about what you want to say!
    I have never seen Robin’s pincushion (how poetic!) in a cultivated rose, nor have I seen a rose ‘invested’ with it. Only one or two per shrub, and I love them. To me they look like very wild elves ;0) Thanks for the beautiful photo, ♥ Johanna

    • English is such a funny language…with all those peculiar spelling rules and exceptions and flexible grammar. It lends itself to all sorts of creativity! 🙂 Honestly, I can’t imagine how tricky it must be to pick it up as a second language. You’re so right, though…all that matters is that you are understood.

      I love your analogy of the robin’s pincushions to wild elves – that’s a wonderfully apt description! 🙂

  2. Geez, never seen one of those. Very cool and interesting info. Thanks for featuring it. Can’t say I’d be keen on using it in the house either. If the wasp larva hatch next year, that would be the pits. I might enjoy the ‘Robins Pincushion’ for a bit then ‘Hasta La Vista’ it to the trash.

  3. I literally haven’t seen Robin’s pincushion. But I have seen rosehips. The rosehips in your photo have a beautiful rich colour. Are you able to access them for harvesting and jelly making?

    • The rosehips this year are absolutely AMAZING – I haven’t seen them like this in years! The only thing I can figure is that the intense rains we had in June spurred massive flower and fruit development. I’ve gathered a few already and made raspberry-rosehip jelly (I will post the recipe eventually; I’m hoping to do a series of canning posts in the near future), but I’m hoping to get quite a few more. It should be easy – every rose I’ve seen is laden with them.

  4. I have never seen one of those, but what strange-looking growths – and do like the name too! (I wonder who Robin was…) I’d never thought about the new usage of “literally” before either… interesting! I think I miss out on developments in the English language sometimes, living in Germany.

    • They are so peculiar, aren’t they? It’s fascinating that the plant responds in such a way to the infestation…I saw a few photographs of mossy rose galls on the Internet that were more spiky than hairy, so I guess roses will form them in different ways.

      I always have to marvel how fluid the English language is – I wonder if it has ever historically experienced such a period of massive change as it seems to be undergoing now. Perhaps it has something to do with the Internet and social media.

      • Oh, and I just posted up a Wikipedia link for more information about mossy rose galls…the article mentions that the “Robin” in Robin’s pincushion is a reference to the English woodland sprite, Robin Goodfellow. Fascinating!

  5. I have only ever had one in 35 years of gardening..I think they look great..and I would leave it to do it’s own thing….if you haven’t noticed the rose in the garden till now you may have had them before with no further problems…enjoy.

    • Thanks so much, Sue! I just realized when I read your comment that I omitted the phrase “on my way to work” in my post; that would lend some clarity that wasn’t there before…oops! I’m so sorry to you and everyone else – I will fix that now! (Apparently I should do my writing on more sleep!). This plant grouping is in a public space, and I’m not sure anyone else has noticed the galls and will prune them out. I just find it so interesting and strange how I’ve taken the same route on a very regular basis and never bothered to actually look and recognize what was growing in that area ever before.

      Have a wonderful day! 🙂

  6. Very interesting post, we do see these pincushions quite a lot but as they don’t do any harm we just admire them. If you wanted to use them for arrangements why not put it in a bouquet on the terrace – looks great and the bugs stay outside 😉

  7. I’ll definitely watch for this on my roses. Like you I am not keen on wasp larvae in the house. Although not all wasps will sting people, did you find out much about the wasps that cause the gall? Either way, robin’s pincushion is a great common name.

    • I should have posted up some links for more information about the wasps; I’ll do so now! They’re non-stinging wasps, and very small – according to Wikipedia, the adult female is .2 inches, slightly larger than the male.

  8. Isn’t it amazing, how much we miss, how much we pass by each day on the way to where we are going. I think when I started blogging is when I started to take the world a little more seriously. I couldn’t describe my world to some one else if I didn’t stop to look at it a little more closely.

    • That is very true…there are small beauties and wonders everywhere around us. It takes effort to notice them all, however, and I know I get caught up in focussing solely on my destination, and I forget to look. It’s something I have to train myself to do.

    • A couple of years ago, I saw much smaller moss galls on a ‘Hansa’ rose – they didn’t look much like these ones on the rose that I’ve posted about here. I didn’t realize there were different kinds of moss galls. Quite interesting!

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