Non-native, non-invasive

Cowslip  Primula veris

Islands are very special places and whilst their wildlife may not be as diverse as that of the nearest mainland, sometimes it has evolved to have some unique characteristics. Isolation also makes island communities very vulnerable to the arrival or introduction of non-native species, including those which may be native to the mainland. So not only are we fighting to control and eradicate invasive plants like Gunnera and Rhododendron ponticum we also have problems with hedgehogs and feral ferrets. Everyone adores hedgehogs, but since they were introduced here in the 1990s they have spread through the islands and are having a seriously detrimental effect on our populations of breeding waders. It is perhaps not commonly appreciated that hedgehogs are partial to eggs.

The climate in Britain has warmed over the last four decades, and in response to changing environmental conditions, some species have been able to extend their distributions northwards. The extent of distribution changes has varied greatly among species, with some showing rapid expansion and others showing none at all. Many of these changes do not appear to have an adverse effect on the local flora and fauna but there will be cases where the effect can have a significant effect on the local wildlife.

Here, in the Outer Hebrides, perhaps the most noticeable effects have been the appearance of some new species of butterflies, orange-tip, speckled wood and peacock, in recent years.

Deciding whether the arrival of new species of plants is natural or the result of a deliberate or accidental introduction is more difficult. Cowslips, Primula veris, are not native to the islands, but they have been recorded in South Uist on a few occasions in recent years. I grow primroses, Primula vulgaris, in the cottage garden, but they have not spread beyond the garden. It is a native species so I would not be too concerned if it jumped over the garden wall. I have never grown cowslips, so I was rather surprised to find them growing on a grassy area near the fruit cage and in the grass along the drive. These areas were not sown and are just areas of grass which we keep mown. To be honest they are more of a mix of wild flowers (including dandelions, docks and other assorted flora which is usually classified as weeds) and coarse native grasses than a manicured green sward.

So the origins of the new arrivals are obscure – natural colonists or an accidental introduction? Whatever their pedigree they are welcome, but I will be moving them into the cottage garden just in case they have hidden invasive tendencies.

13 thoughts on “Non-native, non-invasive

  1. Cowslips are lovely. I hope yours spread enough for you to enjoy them but not too much to be a nuisance. I put one in last year from Angie and am waiting to see if it flowers for me.

    • I hope they’re here to stay and they look lovely growing in the grass. I’m sure they’ll be well behaved and if you plant doesn’t survive I’m sure I can send you a Hebridean invader or two.

  2. I started with one little plant, which has become a few more plants. Don’t put them near the primroses or you get candelabra primroses. See the photo on my Instagram page! 😱 it will be removed….

    • Primulas are remarkably promiscuous and profligate with their seed. I’m not sure whether I can keep the cowslips in quarantine, particularly as I’d like to grow them both. Perhaps I’ll just have to cull the progeny!

      • Yea, I struggle to pull up any plant that grows so I might put the hybrid in a far, far corner, Or just stop them self seeding 😄

        • The trouble with hybrids is that you never know when you will end up with something quite exceptional. As I’m always short of plants, I tend to leave the unidentified until I’m convinced that it is a weed or not garden worthy! I particularly dislike the pale pinkish primroses, but life is far too short to dead head primroses! The sun is shining so time to go gardening!

          • Have a productive day! I like my pale pink primrose, I brought t from the family home, one weedy plant Growing in deep shade. Would really like the Scottish primrose but life’s too short, enjoy what you receive ! 😄

  3. It’s interesting to wonder how the seed arrived on your island, I guess there are lots of possibilities. Would hedgehogs be moved to the mainland where they are in decline?

    • First to put everyone’s’ mind at rest, our “unwanted” hedgehogs are repatriated. The arrival of the cowslips is being hotly debated and the discussion wide ranging.

  4. Hello C,
    Your observations about the cowslips are interesting. In discussions about the restoration of traditional hay meadows recently down here, many commented on how even after decades, new species will emerge in a permanent sward. Are they the result of extreme longevity of a seed bank, or are they introduced seed – presumably from birds or small mammals? I do know many species have extraordinary seed survival potential under appropriate conditions.
    In your island scenario, presumably if not introductions by 2 legged mammals, they must arrive in bird’s guts? Or could they even be washed up? I’m guessing that apart from the few plants like orchids with really fine seed, wind blown isn’t an option, given prevailing directions.
    But then again, given your weather ????
    Best wishes

    • Hello Julian, thank you for the thought provoking response. At the moment we think that the cowslips were an accidental introduction possibly through the use of wildflower seed, which often contains cowslips or through imported hay. As I use manure from the neighbouring croft which contains straw the latter is possible. We know that seed can remain viable in the soil for decades and possibly centuries, so native seed is a possibility too, although cowslips are not common in the NW of Scotland. Other routes are also feasible, particularly as it is thought that Irish lady’s-tresses (Spiranthes romanzoffiana) was introduced by wild geese!

  5. Interesting to read about the need for hedgehog repatriation – I am sure few people would have thought of them as egg eaters although thinking back to the Alison Uttley books I remember the Rat stealing eggs and hedgehogs are not too dissimilar apart from the absence of a tail and the presence of spines… It always surprises me when plants ‘appear’ in my garden and these and your cowslips are another of nature’s many mysteries – although at least the latter are very generous in their seed production and I quite like the idea of candlebra primroses…

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