Saturday 24 May 2014

ancient weeds

The horsetail season has started.  Or rather, the horsetail plucking season is seriously under way. The horsetail is there all the time.  Even when you can't see it, its brittle black roots are tucked away out of sight, reaching down who knows how many tens of yards, waiting.  Horsetail is eternal. Sometimes described as a living fossil, horsetails have been around for over a hundred million years.

Equisetum arvense, the common horsetail, is an ineradicable weed.  It dies down come the autumn, though once you have got your eye in you can spot the dried stalks for months afterwards.  It doesn't make an appearance again until spring, when the first thing you will see are spore bearing stems, looking like a cross between a toadstool and a pipe cleaner.  Once the spores are ripe, the lightest tap will send a cloud of them flying.  As the reproductive bodies wither, the leaves begin to emerge, pointed bright green tips, which elongate to form stalks with green bumps on them, the bumps elongating to form whorls of unbranching side stems as the stalk grows.  The stalk is fragile, formed of many segments, and a light tug will bring the top section away as it parts company at a node.  In the right growing conditions horsetail will form a dense bright green patch over a foot tall, and there it will remain until autumn, when it fades, the old stalks turning the colour and texture of rotten straw.  The remnants of the side branches betray the fact that it is not straw, but something more threatening.

Threatening if you are a gardener, because you will never, ever get rid of it, if you have got it and the conditions are right for it to grow.  It is a plant that thrives in badly drained soil, and in our garden it ramps through those beds where the underlying London clay rises close to the surface, while being totally absent from the free-draining, sandy front garden and the meadow, which is on light soil.  Dig down a foot in the front and you will hit bright orange sand, which is why we were threatened with having a tenth of the entire parish dug up for sand and gravel, and only escaped by the skin of our teeth.  Dig down a foot or two in the back garden, where the garden slopes down to the ditch, and you will hit clay, earth so stagnant and airless it has gone grey.  That is classic horsetail territory, and it abides eternally, coming up each year in borders and grass alike.

Looking on the bright side, it is not a competitive weed.  Other plants don't seem to mind sharing their space with it.  It is not even ugly, only too ubiquitous.  There is no way of getting rid of it. When we first lived here, and I discovered what we'd got, I used to try and fork the roots out, spray them with glyphosate after crushing them to aid absorption, and even paint them with glyphosate-laced wallpaper paste.  It was all completely futile.  I have heard Bob Flowerdew on Gardeners Question Time suggest that if somebody were to grass their entire plot and grow only standard shrubs for a few years, while keeping the grass well mowed, they might drive out the horsetail, but I don't believe it.  And I know from personal experience that a couple of years under black plastic, or longer, do not kill it.  Stop mowing, restore the light, and it will be back.

I pull it up.  Holding the stems near the ground, so that they don't snap half way down, I pull steadily, and the whole stem comes away, sometimes with a few inches of root.  There will be regrowth later in the summer, but it won't grow nearly as tall as the original stems, and as long as there's no bare soil but continuous groundcover, the second crop of stems will be fairly invisible.  A knowledgeable gardener would be able to spot them, and know I had a problem, but they aren't too visually obtrusive second time around.  I am so paranoid about spreading the weed that the stems, and every scrap of plant material weeded out of the ground in the back garden, goes to the council tip and not on my own compost heap.  This is probably an unnecessary precaution, given that the roots run like mad if they like the conditions and the horsetail throws out spores every year, so it has probably got everywhere it wants to go under its own steam, and is not planning on visiting the other parts of the garden.  Nonetheless, I could not bear to compost it myself.

Luckily it doesn't really get going until early summer, so I can enjoy the dwarf bulbs, primroses and other spring flowers without worrying about it, and make sure I plant groundcover that will be reasonably tall by June in the areas where it is a nuisance.  As weeds go, it is not the most difficult to coexist with.  The only trouble is that pulling it up does take a lot of time, hours of work that in an ideal world would be spent doing something more productive and creative.  When we bought the house, we had no idea that it was there.  If we had known, would it have stopped us?  No.  It is a nuisance, but not in the same league as a major honey fungus infection, or Japanese knotweed.


No comments:

Post a Comment