While Notes from the Sticks is on holiday, we are repeating some earlier articles. This was first published on May 9, 2021.
I HAVE always been fond of slugs (and snails, but I will do them in another blog). I believe I have the world’s largest and finest collection of ornamental slugs.
One of my earliest memories concerns slugs. I must have been about six. My grandparents lived in a Victorian house in Huddersfield divided into flats. They had the downstairs and my aunt and her family originally had the upstairs, but by this time they had moved out and the upstairs flat was empty. One afternoon there was a big family gathering and while the grown-ups were nattering, my cousin Wendy, then aged about four, and I went upstairs. We found a big toy truck that had been left behind and it seemed a good idea to take it outside. It had been raining and the ground was covered with big black and orange slugs, probably Arion ater:
and Arion rufus:
Arion rufus in particular has a habit of swaying if disturbed. I wonder why?
Anyway, Wendy and I spent a happy time collecting as many slugs as we could pile into the toy truck then we took it upstairs to play with them. When we were called down for tea we forgot about the slugs, probably until it was time to go home. At that point someone went upstairs and found the slugs had made their way all over the empty flat. I can’t remember what happened next but I imagine they weren’t very thrilled. Apart from anything else those big slugs are intensely slimy – it is almost impossible to get off your hands.
Slugs have a terrible press, mainly because they eat garden plants. So I would like to put in a good word for them.
First, where do you think dog mess and other excreta goes if is not cleared up? Much of it is eaten by slugs, particularly the large ones. OK, it is not a very charming thought, but would you want to do it?
Second, there are about 40 types of slug in the UK and only a few damage garden plants. The rest eat dead and decaying vegetable material. As I said in this post on moles, I am not in favour of killing things for cosmetic reasons, and there are ways to live with slugs.
I have gardened for many decades without ever resorting to slug bait, partly from principle and partly because we have always had various pets that might have helped themselves to it. I have found there are a great many garden plants that slugs don’t touch, far more than the ones they do like. When I see a wonderful display of delphiniums or dahlias, I fear my main reaction is to imagine the masses of killer chemicals that have poisoned the soil to achieve the effect. Examples of plants that slugs take no interest in are perennial geraniums, day lilies, crocosmia, leucanthemum, almost anything with grey leaves, Japanese anemone, ferns, euphorbia, penstemon, alchemilla, roses – you can find long lists on the internet. (How helpful it would be if plant retailers told you which plants are susceptible to slugs but they never do.)
In recent years I have discovered a miracle – copper tape. I have never been able to grow hostas, which I love, in the ground, but thanks to the tape I can grow them very well in pots. Here is a picture I took yesterday:
(They were in a bigger pot which broke in the frost so I hacked off lots of roots and crammed them into this smaller pot, but they don’t seem to mind a bit).
Slugs are partial to lupins so I don’t normally bother with them. But nine or ten arrived free with some other plant order, so I thought I would bung them in a pot with tape. Lo and behold, they are growing like stink.
You can get copper tape pretty cheaply from the internet and it lasts a few years before it falls off. Two warnings: It is sharp so best to wear gloves while applying it, and be careful the pot is not close enough to anything else for the slugs to stretch over the gap (unlike in this picture!) It would probably a good idea to repot with fresh compost before using the tape as well, so that there are no small slugs or eggs lurking. With these precautions you and the slugs should be able to live in perfect harmony.
This very day one of nature’s most remarkable phenomena is taking place in the United States. Trillions of cicada nymphs which have been underground for 17 years will emerge almost simultaneously, shed their juvenile skins, take flight, mate, lay eggs and die within four weeks. The newly hatched nymphs will retreat into the soil and stay there for another 17 years, drinking sap from tree roots.
There are about a dozen cohorts of these cicadas in the US, all appearing every 17 years (but not all the same year). This year’s cohort, which last appeared in 2004, is known as Brood X (Roman numeral for 10). They are found across a broad swathe of the US (there is a map in this excellent article, which tells you everything you could want to know about them) with a massive concentration in the Washington DC area. There can be as many as 1.5million cicadas per acre. Three species are involved, mainly Magicicada cassinii, with distinctive red eyes.
These are indistinguishable from another species called Magicicada tredecassini which has three cohorts with a 13-year cycle. The two types are usually called ‘periodical cicadas’ and they are not found outside the US. The ones you may hear (or very rarely see) on holiday have shorter lifecycles, though again they spent most of their life underground as nymphs. There are about 3,000 species worldwide.
Brood X started emerging a few days ago but today is predicted to be the peak in the Washington DC area, when the soil temperature a foot down should reach 64 deg C. The nymphs will tunnel out of the soil and climb any vertical surface they can find while they shed their skin. At first the new adults are white but they colour within hours and then they are off to find a mate (which should not be very hard, given the numbers). The males produce the distinctive sound and when there are so many it must be deafening. They don’t bite or sting, so I hope our American friends will be kind to them and enjoy this extraordinary natural event.