Written by Noel Kingsbury
We’re delighted to have Noel contributing to GGW. Alot of you are most likely familiar with his name. He has written several books; I have more than a few of them on my bookshelf. As well as being a prolific writer, Noel is a lecturer on plants and gardens. He has been in the nursery business as well as doing garden design. Mostly known for his promotion of naturalistic and wild-style planting design, his gardening interests are wide-ranging, global and eclectic. Two years ago Noel completed a PhD with the University of Sheffield on long-term plant performance; he is hoping to continue research on a number of different fronts. He has a fantastic blog that’s worth checking out. Fran Sorin
I think everyone on the garden lecture circuit has a least favourite, but frequently asked question from the audience. Mine is “what about small gardens?” my own fault as the most dramatic pictures I show are usually of larger ones. Piet Oudolf’s is “when do I cut my perennials back?” There is a somewhat pained look on his face, as to him this is a rather absurd question. His reply is always “when you want to”.
Once upon a time there was always this idea in gardening that there is a right way and a wrong way to do just about anything. The right way would be explained in a Royal Horticultural Society manual (I always wanted to write a book – ‘Digging a Hole, the RHS Way’). Nowadays we tend to be more pragmatic, but those new to gardening still yearn for clear and unambiguous instructions.
I think Piet’s answer to the issue of when you cut back deal perennial growth at the end of the year is that this is a question of personal taste.
There is a subtext – which is ‘how wild do you want your garden to be’? Some of us have spent a lot of time promoting the idea of the beauty of seedheads, of grasses waving in the wind or of winter sunlight on the infinite variety of fawns, golds, browns and reds of perennial stems and seedheads. But we have to recognize that it does get tattier as winter progresses, and if we get a rainstorm or high wind, a lot of stems collapse soggily and untidily. In the west of England this happens a lot, so the winter seedhead look has had quite a bit of ‘won’t work here’ type criticism.
Personally I always cut back in two phases. One is in November and involves taking out anything which looks a mess or will do shortly. That leaves grasses, which nearly always stand better than flowering perennials, and a few really sturdy perennial stems. Of the latter I have a particularly fine form of Joe Pye Weed, a Eupatoriadelphus fistulosus from seed collected in North Carolina by Ed Steffek. Very narrow and at 3.4m (9ft) its very statuesque. I’ve even had American visitors drooling over it. Worth leaving for the winter. If you chop everything down and you have a winter wonderland hoar frost then you have nothing to look at. Leave at least a few stems of something and a hard frost can create the most magical effects out of the most unpromising material.
Phase two of the winter chop is in February, just before the first snowdrops poke their noses up (have to avoid crushing them underfoot). That’s when grasses, Jo Pyes, everything goes.
But what do you do with all the debris? As someone who has promoted big perennials, prairie plants, grasses, I have to admit that this can be a problem. There’s a lot of stuff. A lot of it is tough stuff, still in the compost heap a year later stuff…. miscanthus grasses are the worst offenders, they’re so tough they’re almost woody. If you have masses of space and like carting armfuls of dead perennial stuff around you can build yourself compost heap city. But most of us haven’t the space.
What you do with the debris is related to how you cut it down. Secateurs and occasionally shears will do most small-scale dead perennial borders. A hedgetrimmer held at ground level is pretty effective too – most of the work then is gathering up. Increasingly though I like the idea of shredding and just returning the debris as a mulch – no transport miles and just recycles the nutrients. Probably good for invertebrate bio-diversity too. I am told that some folk feed their herbaceous debris into a shredder, but my experience here is that they clog pretty quickly with herbaceous as opposed to woody stuff. But I’m open-minded and waiting for suggestions of a shredder that might do the job well.
Managers of some larger gardens with lots of perennials use a hedgecutter and then ride over the borders with ride-on mower to shred the material. Would be good if I had a ride-on mower. So I tried a brushcutter – the nylon cord of course is no good against miscanthus, ironweeds, goldenrods etc. The metal blade chops off at ground level but won’t shred in the way the cord does. I tried a serrated-edge plastic blade made by Oregon, did a great job, then a metre in the plastic tears and goodbye. I reckon I would have used a whole packet of the little blades just to get half way through my prairie border. So, back to the blade (by the way, I HATE power machinery, all that smoke and noise is so utterly antithetical to the whole spirit of gardening), and I’ve now developed a cut’n’-mulch technique I’d like to share:
- cut it all down at the base
- rake up debris into low piles in the border
- attack with low-angled slashes with the brushcutter blade towards the centre of the heaps until you have got it all down to bits less than a foot long
- vaguely tidy up with the rake
OK it looks a bit messy. But most of the people reading this will be American, you get more snow than we do. Snow is the great leveller of dead herbaceous. A good snowfall and it’ll be crushed to the ground as mulch. Nutrients recycled, compost heap left empty for other stuff, nice mulch, goodbye. Wait for Spring to come.