Tuesday 23 June 2015

Pilosella aurantiaca (fox and cublets, tawny hawkweed)

Failed garden lighting
      My wife was keen to get some lighting in the garden and came across something which seemed ideal: it was a string of glass globes each with a small bulb enclosed, and powered by a small battery in a water-tight control case. The whole thing was supposed to be weather-tight and it worked perfectly for the whole of last summer, creating a halo of light around the arch I fixed it on. However the winter rain brought into question the meaning of 'weather tight', because each globe contained a pool of water when I came to look at it. At first, this seemed to offer interesting possibilities when I thought about it: why not inhabit each globe aquarium with some sort of miniature fish, so that giant piscatorial shadows moved round the garden when I switched on. If wouldn't matter if the water were to short out the bulbs because the resulting electrical hiatus would simply result in fried fish ready to supplement barbecue festivities. This theory bit the dust when the whole damn thing refused to work at all.The only benefactors of this failure were the theoretical fish.

      Fox and cublets' ( Pilosella aurantiaca) is the name my wildflower book gives a plant which moved in with us a year ago. This is related to hawkweed and dandelion, so I was chancing my luck when I decided to let it be and see what happened, the invasive potential of anything close to dandelion being worrying. It just got a lot more worrying when I read up about it in order to write this: apparently it can propagate itself vegetively by rhizomes as well as by seed and pundits strongly recommend that you don't grow it in the garden. With this in mind, I'm going to allow it to gift me the benefit of its flowers, before uprooting it and embarking on some less worrying challenge,

Fox and cublets behind emerging Agapanthus
      Another name for fox and cublets is tawny hawkweed,  It was introduced to Britain and Ireland from alpine regions in Central and Southern Europe in the early part of the seventeenth century and has widely naturalised since then.
Fox and cublets (Pilosella aurantiaca)

Wednesday 20 May 2015

Duckweed (Lemna minor) and water hawthorn (Aponogeton distachyos)

Top pool which overflows to create the waterfall into the pond 
       I was confronted with an interesting conundrum yesterday: my pond is enlivened by a waterfall which works  on the basis that water spills over from an upper pool which is fed by a pump.The puzzle was - how did tadpoles get into the top pool? The pump is switched on each day and the turbulence means that nothing lives in it on a permanent basis. Only two possibilities came to mind: a. they had climbed up the sheer rock face from the pond, or b. they had passed through the pump, shot up the pipe and been regurgitated into the top pool.

      I ruled out possibility a. by close examination of the tadpoles in question and could determine no sign of climbing boots. In any case, there were no feet to put them on. The more I thought about it, the more unlikely that option seemed. Also, imagine the conversation;

"'Ey, pass the belay device, Tad"

"Oops, sorry Tad - forgot to bring it - let's have an alga butty", say six voices. And this brings another difficulty regarding working in teams - they all have the same name. Derived from middle English, 'tad' means 'toad' and 'pol' is 'head' and goes some way to explaining Mrs Thatcher's poll tax, although I'm damned if I know why parrots are always called Polly. The comment about alga raises further questions: read any advice about what to feed pet tadpoles on and top of the list is boiled lettuce. Boiled lettuce????? Where the hell does a tadpole get lettuce, let alone a boiled one? And who found out that they like it? Somewhere there must be a bloke who's devoted his career to tadpoles, trying different menus and maybe conducting psychological studies. Tadpoles in normal circumstances eat plant material, small insects and even each other if times get hard. Drop a bit of Spam in the pond and they'll demonstrate their lack of discernment by descending on it in hoards.

That left option b. and the difficulty here was the fact that there is a filter on the pump to stop it getting clogged with weed and other detritus. I can only think that tadpole body structure at an early age is so flexible that they can be squeezed through the workings of the pump without being damaged. Admittedly some of them did look a bit punch-drunk but apart from that seemed unmarked. Maybe they sported other injuries like black eyes but it's hard to make out a black eye on a tadpole.

      As I watched, they departed in the water rushing over the edge back into the pond. They seemed to be taking turns at doing it, bringing to mind the water chute at one of those woodland holiday resorts we once took our kids to. When I moved closer and held my breath I swear I heard them shouting wheeeee! as they went over the edge.
Waterfall with water hawthorn
      A tadpole reentering my pond via the waterfall will quickly come across a floating patch of water hawthorn, also called water hyacinth (Aponogeton distachyos). This is a South African semi-evergreen, rhizomatous, pond plant which adapts well to the English climate. The white flowers, resembling yacht sails, appear in spring and autumn during the cooler weather and accordingly it is a good companion for the water lilies which  flower in the heat of the summer. It has an attractive scent which, as this can best be appreciated by putting your nose close to the water, is probably best enjoyed by the recuperating tadpoles.
Water hawthorn (Aponogeton distachyos)
      Providing company for the water hawthorn is the ubiquitous duckweed (Lemna minor). This consists of tiny leaves with a single floating root. Two plants will bud off the parent and the effect is a quickly spreading carpet over the surface of the pond. It doesn't like the cold, so in winter it forms organisms called 'turions' which sink to the bottom and remain dormant until spring. Then it restarts growth and pops up again ready, like a Nazi u-boat, to see what devastation it can cause.
Duckweed (Lemna minor)
      Duckweed can be a problem, because in carpeting a pond it cuts out light to oxygenating plants lower down, leading to their death. The resulting de-oxygenation of the water has a knock-on detrimental effect on fish and other water life, so regular skimming of the plant is desirable. Birds (especially ducks) and fish eat the stuff and apparently it is sometimes grown as a commercial crop to provide feed. I find it a useful regular addition to the compost heap. The turmoil caused by the waterfall restricts spread to some extent, but skimming is still necessary. A difficulty in doing this at tadpole time lies in the fact that the taddies like to feed off the bottoms of the plants, so you always get a net full of the little wrigglers and separating them is a bit of a nightmare.

      Successfully getting completely rid of duckweed is an unlikely scenario, due to the potential of each single plant to so quickly replicate. Its sudden appearance in your pond can be explained either by the fact that the sticky roots have adhered to birds feet and plumage or, in some cases, the introduction of new oxygenating plants which have the odd bit of duckweed attached. Either way, compromise and learn to live with the little floater. The tadpoles like it.

      For information about frogbit, a plant with apparent relevance to the tadpolian nature of this blog, go to Frogbit.


Sunday 19 April 2015

Rosemary beetle (Chrysolina americana) and Pyrethrum

Rosemary beetle
      My daughter had bought me the full dvd set of 'Dad's Army' series and I'd taken to watching one a day in my study while I ate lunch. This was very handy because each episode was exactly lunch length. On this particular day I was due to visit the doctor for some minor surgery at 2pm, so I went to the door a few minutes before the story ended, with a view to getting ready. That was when the trouble started, because it wouldn't open. The handle turned but the spigot, latch, or whatever that thing is called that goes into the door frame, didn't move.

      When you're abroad and you don't speak the lingo, you raise your voice and shout your gibberish, indignant that the blasted natives haven't bothered to learn English. So it is when a door lock doesn't work - you shake it harder. Unfortunately the success rate is the same.

      I looked out of the window but it didn't give an option - there is a steeply sloping roof immediately under it, subtended by a drop of about twelve feet. For a moment the old opening credits of Starsky and Hutch came to mind - the bit where they jump from a first storey window and land backside first on the roof of a car. If we could just get the Toyota under the window..... But no, it'd put a hell of a dent in the car roof. I've a feeling that's why Starsky did it on someone else's car.

      "I can't get out", I shouted to my wife, while I hammered on the door, bitterly anticipating the inevitable comments about old ladies and lavatories. After a few minutes of shouting, I heard her come up the stairs. She grabbed the handle and rattled it.

      "It's stuck", she said after a long period of rattle.

      "I know it's bloody stuck," I bellowed, "I had noticed", and with some difficulty I  resisted the temptation to  display my expertise in sarcasm by enquiring as to the Pope's religion. "I've got to get to the doctor's. Maybe if I could unscrew the handle?"

      There followed a long period of getting a screwdriver into the room. It wouldn't go under the door, so we had to be creative: eventually she got some garden twine from the greenhouse and pushed it under the door to me. I then lowered this  from the window and she tied the screwdriver on the end. Having then unscrewed and removed the handle the position wasn't greatly improved because there was just a small hole with a square bar of metal sticking through it. The bar turned easily but still didn't move the latch. Things were getting desperate. My appointment time was getting closer and I needed to set out.

      "Don't panic Mr Mannering", came the voice of Jones the butcher from behind me. That really helped my blood pressure.

      John Wayne suddenly sprang to mind.- on numerous occasions  I'd seen him put is shoulder to a door and burst into some cowboy cabin. I didn't want to damage the door but we'd run out of alternatives.

      "You'll have to throw yourself at the door and bust it open", I shouted. temporarily missing the point that  John Wayne's height of six foot six against a film set balsa wood door didn't compare well with my wife's five foot two against solid pine.

      There was a short silence followed by a sigh, a thump as the door bulged slightly. then another bang indicating that she'd bounced off the door and hit the banister surrounding the top of the stairs. Thank God she hadn't gone over the top - I could have starved to death in there.


      "What's up?"

      "I've hurt my shoulder".

      So much for the human battering ram.

      "Go and get Terry", I shouted, saving the sympathy for later. He's a bloke who lives across the road. He  isn't exactly John Wayne but he's quite big. I watched from my eyrie as she crossed the road holding her shoulder, only to determine that Terry wasn't in.

      "We're all doomed - doomed I say", came the sepulchral Scottish tones of Private Frazer, with startling appropriateness.

      "I'll see if Bert (name changed to protect the innocent) 's in" she shouted, heading next door.

      Bert usually worked away but, by a miracle, on this occasion he was in. However, when he came to the other side of my imprisoning door his first words were: "unfortunately, I've got a bad shoulder"

      'Christ', I thought viciously, 'the next person she gets to 'help''ll probably be in an iron lung or a wheelchair.

      "But I could try this", he continued after a moment's thought. There was a short silence, then the door, plus a piece of the frame, suddenly shot into the room closely followed by Bert, moving backwards. It seemed he'd employed the technique of bending suddenly and applying his not inconsiderable bum to my B&Q budget pine. Luckily, the door just missed making contact with me, otherwise the minor surgery at the doc's could have become  major.

      I suppose that if there is a moral to this story it is that, to save bothering neighbours, one should marry a seventeen stone woman.
Rosemary beetle damage
      And as if I didn't have enough problems with the door, I discovered the following day that my rosemary plant had suffered a severe attack by some tiny (8mm long) insects. These were rosemary beetles, a relatively new pest probably brought in on plants from their native habitat in southern Europe. They also attack lavender, sage, thyme and a few other plants and the common factor seems to be scented leaves. According to the RHS they do most damage between late summer and spring and the plant recovers early on with new growth, only to have it eaten back later on. I think this is because in the spring they are too busy having sex to bother with eating. Most of the ones I came across were doing it, unless they just enjoy playing piggy-back. The larvae (baby beetle) is slug-like with a dark stripe along the side and it also feeds on the leaves until full up, when it falls to the soil, where it pupates for the winter.

      The RHS are doing a survey of the spread of the beetles and would appreciate people filling in a short questionnaire if you come across them. If you can help, just Google 'rosemary beetle RHS'.

      The beetles can be killed using something like Provado Ultimate Bug Killer but care should be taken not to spray when the plant is in flower as bees will also suffer. It's also a not good idea  to use this if the leaves are to be used for culinary purposes, unless you have a death wish for someone in the family. Pyrethrum, on the other hand, is an organic pesticide extracted from Chrysanthemum cinerariifolium. Working on contact, it is soon washed off the plant and, in any case, has little toxicity for humans. It can be used to kill caterpillars, beetles, scale insects, leaf hoppers, thrips, whitefly and others. However, in the case of the rosemary beetle the RHS think it only effective against the larvae. A good organic compromise therefore is to place newspaper under the plant, shake the adult beetles onto this, stamp on them, then spray Pyrethrum to get rid of the larvae.

Rosemary beetles mating amongst the wreckage of the plant

Monday 30 March 2015

The Natural Garden

      The Natural Garden
The pond - a wildlife magnet
      I got a phone call the other day. It was my youngest (he's 29) son, Nick:

      "Daad", he said, in that whiny voice which still indicates that he's at least involved in some sort of cock-up or, at most, associated with excreta making contact with a fan.

      "Yes", I replied carefully, already thinking up excuses for not getting involved.

      "Canals don't flow, do they?". I sighed. When the children were young I regularly took them out on rambles, telling them the names of plants and birds, while introducing them to the various natural features of the countryside. 'They'll remember all this when they're older and grow up to be naturalists' I would tell myself in a self-satisfied way. In some ways this turned out to be true - they remember our outings but the only details still lodged in their memories are the fact that I made them walk too far, or what was in the packed lunches and whether I bought them an ice-cream on the way home.

      He continued to explain that him and his friend had decided to ride their bikes from where they lived in Levenshulme to the Manchester Ship Canal, which they would then follow to Salford Docks where they would find somewhere to get a pint. So far, so good.

      "But the water's flowing", he pointed out plaintively "there are rocks sticking out and it's getting narrower". The element of doubt in his voice as to whether a canal flows round rocks seemed the ultimate kiss of doom to all my teachings about the countryside.

      Admittedly, this didn't conform with the use of the canal by 20,000 ton ships and it was only by quickly referring to Google Earth that it became clear that a. the River Irwell is the source of the great waterway and b. the equally great explorer was going the wrong way along it. With great forbearance, I resisted the temptation to let him disappear into the wilds of the Pennines, or wherever it is that the damn river is sourced, and pointed out that he had to turn round. Whether he did turn round or not, I'm not sure. What I am certain of is that, wherever he ended up, there was a pub.
Newt - part time pond resident
      I suppose my irritable attitude towards Nick's adventures was coloured by a latest home-handyman disaster: my wife had come up with another 'five minute job'; fix a new ceiling rose and flex in the breakfast room. What could be easier? Well, in retrospect, rebuilding the Twin Towers springs to mind.

      The old fitting was difficult enough to remove, having been there since Walt thought setting fire to a tube of tobacco was a good idea. It was sunk into the ceiling plaster and the modern replacement was designed to sit on the surface instead. This led to the copious application of filler, long screws with plastic separators, and an hour lying flat on the bed in order to get my misused neck into something like it's original position.

      That was the easy bit. The real problem came with the wiring: there was a helpful set of instructions accompanying the new fitting and these seemed to cover all the different potential ways of carrying out the task by wiring in series and various other techniques which would qualify me for wiring Blackpool Illuminations. What it didn't make clear was how it should be done in my little breakfast room. The outcome of  this failing was a loud bang when, with a flourish, I eventually switched on. As if voting in sympathy, all the other lights went out and I expected mine to do the same when my wife came back from shopping.

      Eventually, a life-saving friend (Jim) came with his ammeter and we now bask in bright light under a ceiling sagging with half a ton of filler. If I were to offer a word of advice to any aspiring do-it-yourselfer, it is 'DON'T, or, if the lure is too great, make friends with Jim.
Amorous frogs
      And, just as our civilisation depends on the interaction between the Jims of this world who share their expertise, so the well-being of the garden relies on a network of living organisms who work together to ensure the smooth running of things. As an illustration of what I mean I like to fall back on the example of the cocktail of chemicals once used in an experiment to save an apple orchard from pest attacks: the mixture was great - it killed everything misguided enough to go near the apples. Everything, that is, except the fruit tree red spider mite which, for some reason, remained unaffected. This didn't matter though, because the population of the mite was not great enough to provide a problem.
      Unfortunately, the cocktail didn't only kill the pests, it also bumped off the predators of the red spider mite, causing its population to explode. In one stroke of chemical genius, we had created a new pest. Nature is a web of life which depends on an intricate set of relationships, many of which we are completely ignorant: they self-police to create a beautiful balance and, as soon as we jump in wearing hob-nail boots, havoc can ensue.

      So (I hate the current fetish for beginning sentences with 'so', but in this case it seems fitting) I like to keep my garden as natural as possible by encouraging the myriad life forms which ultimately give that subconcious feeling of being part of something greater.

      A pond is probably the single greatest attraction for wildlife, supporting frogs, newts, fish and a variety of aqueous insects including, if you're lucky, dragonflies and damselflies. By the simple addition of a log pile, shelter for hedgehogs and voles can be created and, easier still, a collection of hollow sticks can provide homes for the solitary bees and wasps which are important pollinators.

      The great Geoff Hamilton was always hammering on about the best balance of nature occurring where there is a wide selection of plants: some harbour pests, while others attract their predators and yet more provide nectar for myriad pollinators. If you view your garden like this success is not complicated - there is a truth in simplicity.
High rise flats for pollinators



Wednesday 25 February 2015

Garden problems

Life's Stage
On the positive side......
      I used to laugh at the old joke about getting one of those high speed chairlifts - 'they get you upstairs before you forget what you're going for' - now though, I'm giving it serious consideration. I'd have sorted it before, but I keep forgetting.

      Surprisingly, a bad memory can have advantages: I can watch a film I saw a fortnight ago and still be happily surprised at the ending - a library of five films and the same number of books will keep me happy into eternity; equally, it isn't a problem when I'm out walking with my hiking mates, I suspect we tell the same story ad infinitum  and yet all remain happy, supremely unbored and wondrous at the creativity of our companions in continually coming up with new stuff. The problem comes when older persons communicate with younger ones. Watch for the signs - if the young person's eyes begin to roll when he thinks you aren't looking, or if he suddenly drops off, then you are doing what your grandad did to you way back.

      The relevance of my memory came home to me forcibly a couple of nights ago: I'm involved in a play at The Lowry Theatre in Salford and we were rehearsing. I have a speaking part and my lines are 'Keith Scott' - I don't think I'll ever be competing with Kenneth Branner for the role but I suppose even he had to start somewhere. Anyway, one of the female leads (a real actor) is playing the part of a school head at a pupils' reunion and she wrongly addresses my character as 'George'. I correct her, saying 'Keith' but she ignores me and calls me 'George Brown', to which I say 'Scott'. While recognising that the part didn't have quite as much meat as 'Hamlet', I had meticulously researched it and was looking forward to producing a dazzling performance. However, at this point I became aware of the other fifty members of the cast all looking expectantly at me and I froze. The only comment which came to mind was 'er, oh shit!' but this I discarded on the basis that some of the crowd looked as if they came from polite backgrounds. Unfortunately, Scott had disappeared as completely as his namesake at the South Pole.

      I now have 'Keith Scott'  written on the back of my hand.

      And herbaceous plants can disappear overwinter as completely as Keith Scott, the difference being that, given enough chance, they'll probably reappear.The trouble is that a gardener is often keen to get the bed sorted early in the year and so starts hoisting out the weeds which have capitalised on the odd mild spell, This results in the removal of friend as well as foe and for this reason I used to carefully stick plastic labels in during  autumn. These were equally carefully removed by magpies and redistributed in the wrong places. Happily, my conversion to the system of leaving dead herbaceous stems in overwinter (because of the wildlife benefits) has resulted in the easy springtime location of the wanted plants. The magpies have had to turn their attentions to other anti-social habits, like removing the putty from round next-door's windows.

       Talking about anti-social habits, I was flummoxed a couple of days ago when I returned to a path I'd only recently recovered from a covering of dead leaves. It had once again disappeared under further leaves. I re-cleared it, dumping them on the adjacent bed where they would work as a useful mulch and eventually break down to enrich the soil. Then I kept watch from the kitchen window each time I went in . This time guilt went not to magpies, but a blackbird who turned up soon afterwards and, with much head - cocking and what I fancied to be a malicious grin (quite difficult when you've got a beak), proceeded to flip leaves from the adjacent bed, presumably in a search for worms.

      This is what gardening is all about: it's a war against cats who find seed beds ideal for digging and crapping in; pigeons who strip the Amelanchier and Cotoneaster of berries before I can enjoy their glow; squirrels who bury conkers in my lawn when not pinching the bird food and next door's teenager who uses my garden as a repository for his football, smashing plants in the process. Actually, I can think of a more appropriate repository but, as you know, I'm very polite.

      I think I'll take up stamp collecting.

Friday 6 February 2015

Winter garden interest and plant health

Winter Interest and Healthier Plants

Betula jacquemonti showing off their bark
     It never ceases to amaze me when the snowdrops and daffodils heave their leaves through the frosty ground for their first look round of the year. A friend living further south (Maldon, Essex) was telling me three weeks ago that the primroses were already up and flowering, though they're still laying low in my Manchester garden.

      A recent visit to the Winter Gardens in Dunham Park reminded me that there are plenty of interesting alternatives to flowers at this time of year: the grove of maturing Betula pendula Jacquemontii flashed their amazing bark in an eye-catching display while the flaking, paper-like covering of Acer griseum caught the light from the low winter sun, imbuing the tree with a warm glow. Contrasting interest was to be found in the growth of Corylus avellana 'Contorta' as the stems spiralled their progress in a way guaranteed to make flower arrangers drool. Another shrub, Cornus sanguinea 'Winter Flame' has become popular relatively recently and deservedly so. With its yellow-based stems travelling towards red tips it is easy to see reasoning behind the variety name. To get the full benefit of this growth it is advisable to prune hard back to a stool in March.
Acer griseum
      On a slightly different tack, I was reading recently about research into plants and aspirin. Most people are aware that willows and poplars produce salicins which, broken down in the human digestive system, become salicylic acid, or aspirin. This explains why the traditional cure for a head-ache is to chew a poplar bud. Taking this a step further though, it seems that plants attacked by disease will produce salicylic acid to combat the ailment. This has led to experiments whereby a plant is watered with dissolved aspirin (one and a half tablets per gallon of water with a bit of soft soap to enable it to stick to the leaves). The results seem to indicate that this has the effect of strengthening the plant's immune system and you end up with a more vigorous, healthy specimen. And, even if it isn't more vigorous, it doesn't get head-aches.
Cornus sanguinea 'Winter Flame'

Friday 5 December 2014

Couch Grass (Elymus repens) Removal.

The Dangers of Wheely Bins
Beware The Bin - it can turn nasty.
      I know from talking to friends that climbing into wheely bins and jumping up and down to compress its contents is not an original idea. On the face of it you would think it was rather a good one, enabling you to get more in. However I feel a responsibility to let the public know it is a recipe for disaster: In my case, the bin was situated against the wall on the narrow path between our house and next door's fence. The bin men weren't due for another week and I'd got a lot of prunings to get rid of. I didn't fancy the monotony  of feeding them individually into my shredder, so the bin was a good alternative. It was about quarter full when I decided it'd be relatively simple to get myself in and do a bit of compressing.

      One unfortunate thing about wheely bins is that they are pretty high, so getting one leg in first, then manoeuvring to get the other one in resulted in elevating my voice a couple of octaves.
Anyway, I recovered from the near sex change and tried the first tentative compressing jump, Unfortunately, the wheels  were situated about a foot away from the wall and the movement caused the top edge of the wheely to press against said wall. Interestingly, this set of circumstances proved that law of Newton's - for every action there is an equal and opposite reaction - I never really understood it til then. The wheels trundled across the path while the top stayed in contact with the wall. The whole contraption, with yours truly in it, jammed horizontally across the path with the wheels against the fence and the lid pressing me further into it. My head was sticking out at an extreme angle and the edge of the bin was giving a fair idea of what being garroted feels like.

      My immediate reaction was to shout "er, help!" in a strangulated voice resulting from the pressure on my larynx. This brought no rush of rescuers footfalls and a few moments thought gave me the realisation that this was a good thing. The amount of help I'd have got from my wife or caring neighbours ('quick - get the camera- the daft bugger's up to his tricks again'), and the months/years of mickey-taking, made this a bad idea. On the other hand, waiting for the bin men to turn up and try to empty me into the back of their grinding monster was equally unappealing.

      Being jammed in a wheely bin is extremely debilitating:  You are completely helpless. This led me to think of  the old westerns where John Wayne or someone would tie up the outlaw with a couple of quick turns of the rope that could be easily negotiated by a two-year-old. A wheely bin would have been far more effective. However the saving grace in my situation was the fact that one arm was free, After a short period of peacefully lying there thinking about it, I was able to awkwardly push sideways against the wall with one hand, In this way, bin and me eventually became at an angle on the path and I crawled out like a butterfly emerging from a chrysalis. My wife would have changed the simile to a bluebottle coming out, but I never gave her the chance and, to this day, she never heard about it.
Uprooted couch grass

      The dangers of wheely bins are outweighed by their usefulness and brings to mind couch grass (Elymus repens) as a good example. Putting the roots of this stuff on the compost heap is a recipe for disaster. Unless your heap heats up very efficiently (and a lot don't), you will end up with bits being spread around the garden when you use the resulting compost. Far better to let the bin men take them away to where they will be killed off by the extreme temperatures in the council recycling unit.

      Chemicals based on Glyphosate (look on the container labels and the constituents of weedkiller or pesticide will always be displayed in small print even if they are not reflected in the trade name) will kill couch. However the problem is that it is not selective: if the grass is growing through herbaceous plants it will kill them as well, so a way round this is to remove the base of a pot, place it over the grass and spray inside. The best time to do this is in the spring when the grass is growing vigorously and so the chemical is translocated throughout, killing the whole root system.

      I've approached the problem in a front border by removing all the herbaceous plants and diligently forking out the shallow growing roots of the grass. This is hard work in a heavy clay soil but my garden is light and sandy, so the job is relatively easy. I will now go over the bed once every few weeks, forking out any new growth from remaining bits and, in the spring, I'll replace the herbaceous plants, having diligently removed any couch lurking among their roots.
Bed awaiting regular forking to remove remnants
      With pernicious weeds like couch and marestail it pays to remember that removal of any green growth as soon as it pops up will prevent photosynthesis taking place. This puts paid to the subsequent build up of sugars which are stored in the roots as growth energy. By starving the enemy in this way it will eventually disappear. I've made that sound very easy, but it takes real dedication to carry through to the end. I've even managed to get rid of marestail (Equisetum arvense) in this way. The problem with this system occurs when weed growth is coming under the fence from next door's garden. In this case the only thing to do is shoot the neighbour. It won't kill the weeds, but you'll feel happier.