Growing perennials in grass

A question at a public lecture at the University of Gloucestershire (bet you didn’t know that Glos. had a Uni. …. well you do now!) last night made me think I should write this up from my PhD. A long time ago (late 1990s) I decided I would run a small-scale experiment on growing perennials in rough grass. I wanted to see if it was possible to create a ‘perennial meadow’, where the grass was cut only once a year. Around the same time James Hitchmough (now at the Uni. of Sheffield) had a similar idea. He, needless to say, was larger-scale and more scientific. Our hope was that we could come up with an alternative to just boring mown grass or long shaggy, but rather untidy grass.

Not actually a great success, but not without some hope.

Problem is, nearly all ornamental perennials have a dormant season, during which our native grasses (which makes up both lawns and pasture) and pasture forbs (like dear old creeping buttercup) are growing, give ‘em a mild winter and the things will grow for 365 days a year. So, perennials are immediately out-competed. This is why you get (or one reason why) you get such fab wildflower meadows in places with freezing winters where nothing can grow Oct/Nov to April, like the Alps, eastern Europe etc. – everything here starts off on a level playing field. Our British/NW European long growing season is just too grass/creeping buttercup+other winter-green forb – friendly.

So, we sprayed off (with Roudup) or dug out circles of grass and planted and watched results. Almost inevitably, both James and I found that plants in year 2 and onwards were so much smaller than we were used to seeing them in borders, out-competed and weakened by the grasses. Very few were able to survive and prosper. My conclusions in my thesis say:

• Effective basal cover, combined strongly with:
• Early emergence
• At least some ability to effective spread by ramets, (ie. new shoots)
• Root competition may also play a part – further research is indicated.

Which means geraniums, especially G. endressii, G. versicolor, G. x oxonianum types,(see pic at top) big inulas (e.g. I. racemosa - see pic below), Rudbeckia laciniata and that's about it. Asters did ok for a few years then got slugged. Euphorbia cyparissias did ok with its manic runner production. Meanwhile James found that Lychnis chalcedonica and Papaver orientale did respectably well too.

Those on planet Academia can check out these:
Hitchmough, J.D. (2000) Establishment of cultivated herbaceous perennials in purpose sown native wildflower meadows in south west Scotland. Landscape and Urban Planning. 714, 1-15

Woudstra, J. and Hitchmough, J.D. (2000) The enamelled mead: History and practice of exotic perennials grown in grassy swards. Landscape Research. 25,1, 29-47

Hitchmough, J. and Woudstra, J. (1999) The ecology of exotic herbaceous perennials grown in managed native grassy vegetation in urban landscapes. Landscape and Urban Planning. 45, 107-121

SO WHAT’S HARDY NOW?

Its hardly crept above freezing anywhere in the British Isles for some ten days now. Last winter was an old-fashioned event, with a frost every morning here for two months, but this one is so like the winters of my childhood, in the Kent/Sussex border area, where every winter in the 1960s and early 1970s there was at least one massive snowfall.

So, where does this leave us with plantlife? ‘Zonal Denial’ to borrow a phrase from American (Oregonian) gardeners has been all the rage over the last twenty years, planting stuff out from warmer climes in the hope that it will survive. And much of it did: vast mimosa trees turning brilliant fragrant yellow in London squares, agaves in urns, olive trees in gardens. Gardeners have always liked to push the possible, and with so much new plant material coming into the country, at a time when we have had a run of mild winters, there have been temptations aplenty. I was (note WAS) part of the trend – indeed perhaps helped start it off. All that exotica that we began to play with in the 1980s and 1990s. In my case, selling plants on a regular nursery stand at RHS shows in London (in the days when these events used to happen) made me realise just how good the city was for growing plants – the urban heat island effect, and a fairly dry climate. People started buying supposedly tender plants like Abutilons and Banksias and then coming back next spring to tell me that it had survived the winter with no protection/ flowered all winter, etc etc.

The architectural plant craze helped as well. Importers of palms, yuccas, bananas and tree ferns had a field day: mild winters, a rush of new plant prospecting AND lots of young folk who had no memory of cold winters with lots of money to spend. Big of a boy thing this – the rather macho world of big exotic-looking stuff, when you could boast of what you could get away with next spring – a bit of defying the ruling gods.

I got out of all this a long time ago, round about the mid 1990s. For me the future lay in stuff which you did not have to worry about every winter or celebrate its survival every spring. The stuff that began to excite me was the perennials and grasses I saw in Germany and Holland, for which a British winter was nothing. Part of me just lost interest in the stress of growing borderline hardy plants. After all, I was now gardening in Hereford, not the south Devon coast.

This winter will probably leave a lot of vegetable mush. Its important we learn from it, about the plants that survive and why they did. It won’t mean we’ll have to go back to the garden world of the 1970s, because there really is a lot of new plant material we now have, a lot of which will probably be ok. But at least the sillier excesses will hopefully be curbed. Like the fool who planted an olive orchard in Devon, and hopefully (and this makes me cross) the wholesale nurseries who sell things like Lavandula stoechas with no warning on the label about its borderline hardiness. A periodic reality check is definitely a good idea.

I can’t help point out though that Mexican Salvia coahuilensis was still flowering before getting covered in snow!

Is England just a bad road movie?

Correspondence following a comment on

Felicity Waters blog - Gardenbeet
http://gardenbeet.wordpress.com/2009/09/13/landscapes-in-the-se-of-england/


Noel - thanks for the comments on my blog. I once cornered one of the senior managers at the roads authority in the UK and gave him an earful - I am from Australia and worked at the road authority for 5 years - we were doing amazing projects - the UK is 50 years behind. And we always worked with Horticultural experts - sometimes from Burnley Horticultural Colleges (Peter May et al)
Amway not meaning to sound egotistically its just that I find the road system is THE LANDSCAPE for so many people these days. It deserves as much consideration as any outdoor area. The UK roads authority has not got a clue about its design responsibility - the UK roads systems is the definition of bad design- its non design- its not even thought about - you get a catalogue of plant mixes and stamp them over the country! These guys need to visit France.

Felicity Waters

Hi Felicity

Thanks for your thoughts – I agree with you that British highway landscaping is crap. In fact an awful lot of British landscaping is crap. My own bugbear has been the massive decline in the quality of planting of our parks and urban green spaces – a group of us did some campaigning about this a few years ago but did not go very far. I was lucky though and managed to do some good projects in Bristol (see my website). And there is one enlightened landscape company (HTA of London) who occasionally employ me as a horticultural consultant.

You are very right about roads being THE landscape for many people. But in fact we are not used to thinking of them as being potentially interesting landscapes – your mention of France is hopeful, I have not been there for years, but will be going this summer so I look forward to some inspiration. One problem we have in the UK is that currently there is some real dogmatic thinking about native planting which an ecology lobby has ended up foisting onto the landscape profession via local govt. and planning requirements. Our native flora is very limited and pretty boring – for landscape purposes anyway. There are a few places I can think of where unplanned nature has done some fantastic things – but very dependent on chance comings-together of low-nutrient soils and the local flora:
April – cowslips along the M5 between Bristol and Gloucester
June – pyramidal orchids ditto
April – early purple orchids and primroses along A38 west of Totnes in Devon
All are great at 70mph!

Do you know Rick Darke – Pennsylvania-based plant-orientated whizz-kid? He has been researching native plantings for highways in Delaware? He has even written a manual on the subject which is really good hardworking stuff. You must see it.

How do you feel about me putting this correspondence on my blog?

Cheers

Noel

Wet, Wet, Wet

I haven’t been in the garden for weeks. It was incredibly wet here (Welsh borders) for practically all of November and well into December – and now it is so cold not much can be done outside either.

The rainfall is high here,nearly  2,000mm per year, and the soil, overlaying Old Red Sandstone has enough clay/silt content to slow down water absorption – so it gets saturated very quickly. When really wet, springs appear, and water can actually flow over the surface of the soil. Pooling for several days after rain is normal. In areas where subsoil or near-subsoil is exposed, it is even worse. The whole garden is on a gentle south-facing slope however so there is constant water movement through the soil and no long-term waterlogging.

So, given all of this, and the fact that we have had three cool, exceptionally wet summers, it is amazing what survives – or put another way, how little fails. Even Mediterranean plants like santolinas and lavenders flourish in sticky poor-quality soil with pools of water around them for days. It is hard to think of any failures: Lilium regale definitely, and I think the raspberries, although there was a complicating factor here, as we dug in loads of manure to ‘improve’ the rather poor-quality soil and I think phytophthora may have killed them.

The year before last there was an exceptional period of high rainfall, in, I think, June. A friend, who lives not so far away, Charles Chesshire, had huge losses, despite being also on a south-facing slope – but in his case, springs or at least great upwellings of water from underground (he has the very substantial Clee Hill just behind him) must have completely de-oxygenated the soil, and at a crucial period of very active growth. Thinking about places where you see plants in the wild, wet slopes are often a good habitat for a wide range of species. The conclusion I think must be that plants do not object to very wet conditions at the roots so long as there is dissolved oxygen in the water, so that they can respire, and that means that the water must be moving. This is more crucial during the growing season than the dormant.

Anyway, we’ll probably have a terrible drought this year, which’ll give us something else to think about.

WHY I WROTE HYBRID – THE HISTORY AND SCIENCE OF PLANT BREEDING

I’ve always been interested in food. Been ahead of the game, but nobody knows this apart from family and friends who over the years have been made to eat all sorts of weird vegetable matter. Like couscous, which nobody in England had ever heard of when I first cooked it in 1977, having found it in a French supermarket, and now finally it is all over the British supermarket shelves too. And wild garlic soup, which I first served up to dubious looking faces in c. 1982, and now it’s rather galling to see that Hugh Fearnley-Whittingstall has discovered it, and it is all over the celebrity chef programmes, pretentious restaurant menus - and I dread to think what wild garlic leaves cost now down in trendy greengrocers in Islington.

One day they’ll realise just how scrumptious stir-fried Japanese knotweed is too. And perhaps one day I’ll find a recipe for ragi that doesn’t stick in your teeth.

Having concentrated on innovation in the garden world, and let’s face it, been jolly successful at it, I finally decided that I had to try to get some new thinking going in the food world too. I think the germ of the idea behind Hybrid came when the GM crops debate hit the headlines around the turn of the century. I only had A level Biology but I was appalled at the nonsense that came from so many people whose opinions I otherwise respected. So many seemed prey to the most bizarre journalistic fantasies – as if Mary Shelley’s Frankenstein was a genetics textbook. I wanted to read some background on the methods used in plant breeding up to now, but couldn’t find anything. And since other folk had written successful books with titles like Salt, Cod, Porcelain etc, I thought that perhaps there might be a market for Hybrid.

Travelling was another thing. Loving to see what people grew in their fields, how they grew it, what they did with it. Buying all sorts of weird dried vegetable matter in Indian markets. Getting slightly non-plussed guides to quiz market ladies about the exuberant but puzzling greenery they were selling. Trying out any new grain, new vegetable, new spice I could lay my hands on. But also seeing how, in much of the world, the downside of agriculture was the destruction of natural habitat for the other species we share the earth with. And here there is a paradox, because what I found myself being most disturbed by was not intensive agriculture – fresh fields of densely-planted crops, but the bad agriculture much of the world’s poor find themselves shackled to – fields where the crops were hardly visible behind weeds, crops shredded by pests, measly and dried-up looking rows of corn. Anyone who in their own garden has lost a row of pea seedlings to mice, seen their nicely-maturing lettuce demolished by slugs, or suddenly smelt the nauseating odour of potato blight can relate to this, and magnified a hundred fold to those third world farmers who can’t just replace their lost crops with a trip to the local supermarket but who might actually starve as a consequence. Apart from anything else the amount of time poor farmers spend on tending crops which give such meagre results. The sight too of how many farmers in marginal areas are forced to fell every bit of forest and terrace every bit of hillside, and let their goats eat every last scrap of not-completely-laden-with- toxin wild plant in order to produce enough to feed themselves. A land of poor farming is a land denuded of natural habitat, of wildlife, and almost inevitably losing its fertility, its water and its soil. This is what so utterly depressed me about Rajasthan in India – an overpopulated Medieval rural slum in a state of ecological collapse.

Researching Hybrid, wading through 450 books, leaflets, articles, research papers, newspaper stories, political tracts, I came to realise just how much we owe the plant breeders of the past, from the scientists to the observant tribal peasant - via the gentleman farmers of the 18th century Enlightenment. And how, with the pressures of population growth and climate change we must go on breeding plants, using every available method, and of course every available crop: manioc, ragi, buckwheat, quinoa, amaranth, urid. Biotechnology opens the whole of creation to the plant breeder; we are learning to mix and match genes to our hearts delight, which is a wonderful and magical thing, and so full of hope. Who owns and controls the technology may be a vexed question, one there are no easy answers to, but there is no doubting our need to grab the technology with both hands - and fearlessly. By researching the history of plant breeding I lost any residual worries I had about GM crops, and I hope my book will give modern biotechnology a historical background and context, and encourage a more positive attitude. And if you did Frankenstein rather than Mendel at school, you can even brush up on the good monk’s basic laws of genetics too.

Giant acorns, bromeliads and dodgy mayors

Another conference in Mexico, or perhaps I should say ‘congress’ as that is the word they use. I roll up right at the end for a final keynote, so I don’t get much sense of what has been going on, except that it is about preserving biodiversity through horticulture.

It looks like these big gatherings are clearly incredibly important here. I suppose in a large and very diverse country they are a good way of getting people together to share experiences and information, learn about new ways of doing things etc. To my eye it all seemed very formal, lots of speechifying and sitting behind important-looking desk signage. An inordinate amount of time and effort promoting the venue for the next congress – Monterrey. The Head of Tourism from Monterrey was there – he showed a video about the wonders of the place and all the activities you can do there: water-skiing, diving, looking at giraffes in the zoo – all the stuff you have no time to do if you are there at a conference (or indeed a desire to); projected so that you couldn’t see half of the image.

On the subject of biodiversity, here in lushly tropical Veracruz province it is truly incredible. Steep hills are covered in dense forest – very little sign of deforestation here, and there is so much to see, very easily. Hilly forest is a much better environment to see plants, and life generally than lowland forest. Slopes allow you to look straight into tree canopies and appreciate the thick growth of bromeliads, orchids, ferns and other epiphytes. The climate is so humid that tillandsias even grow on electricity and telephone cables. Hill forest also gets a lot more light at ground level so the ground flora is a lot more interesting than in lowlands.

One day we had a bus trip to the botanic gardens at Xalapa, one of the few in the world in cloud forest. Needless to say it rained, and while we sheltered in the potting shed listening to Phil Brewster, the English head of hort. we got the occasional deafening rattle of a giant acorn hitting the corrugated iron roof. There are apparently around 150 species of oak here. What is particularly wonderful about the flora here is that northern temperate (like oak, hornbeam, walnut, liquidamber etc) meet tropical and where north meets south.

For a country with such eye-popping levels of floristic diversity, plant availability in the nursery trade is abysmal. I looked through the national catalogue of ornamental plants grown in Mexico’s nurseries – very few were Mexican, it was the same boring list of global ornamental plants. My friend Cruz Garcia Albarado is doing his best to promote more trialling of Mexican natives, and there must be others doing similar things – I spotted a big and impressive book in the Mexico City University Botanic Gardesn on ‘Plants with ornamental potential in the state of Morelos’. At the congress, Cruz got elected to be Il Presdente of AMEHOAC – the Mexican Association for Ornamental Horticulture – pretty good for a chap in his mid-thirties. Got talking to a few people about the whole business of getting Plant Breeders’ Rights onto some cultivars of Mexican plants so that the economy might benefit – tangled topic, but good to make a start. We even talk about trying to get an international congress off the ground – on the subject of introducing wild plants into cultivation.

Veracruz is also pretty safe. So much of Mexico isn’t – owing to the drug cartels’ domination of much of the countryside. On my last visit (Feb 2007 – see blogs) I had given a lecture in Uruapan, introduced by the Mayor (with a great bearhug for the benefit of the local press) – who I thought at the time was a man I wouldn’t trust further than I could throw him. It turns out he is now in jail, on charges of involvement with a particularly nasty cartel who operate in the state of Michoacan – they caught the national headlines once when they flung five decapitated heads onto the dance floor of a disco. One does occasionally meet unsavoury types in the otherwise gentle world of gardening.

Where the plains meet the mountains

An end to some extensive travelling in the US in Colorado, visiting Lauren Springer and Scott Ogden, consummate plantspeople both, with an immensely richly planted and very naturalistic style garden in the burbs of Fort Collins. Its odd looking at the planting here, as it is such a mix of the familiar and the unfamiliar - basically the kind of grass/deciduous/conifer type planting you might see anywhere in northern Europe or much of the US, but with added cacti and agaves.

Its dry here, and although it can jolly cold in the winter and hot in the summer, the reduced moisture level means that it is possible to grow a whole range of plants which would rot in a damper area. Not just possible, but essential, as it is so dry that very little would survive without some irrigation during the growing season.

The Great Plains begin, here - utterly desolate (on a cold day with snow threatening), almost frightening in their emptiness and vastness. No-one seems to want to live here anymore, hardly surprising, and their are deserted houses, whole little townships virtually derelict (including Hereford!), and occasional little cemetries with no sign of any habitation in sight. The short-grass prairie is not much to look at at this time, but instructive to see the visual importance of yuccas, indeed you never feel far from a yucca over vast swathes of the American west.

Short grass prairie at Pawnee Buttes is not that inspiring at this time of year, but there are plenty of flowers May to June.

This is actually quite a nice climate to live in, especially as summer nights are always cool, which Scott thinks is very beneficial to plant growth. Light intensity is incredibly high here (at 1500m in very dry air) so bulbs can perform spectacularly from late winter onwards. The skiing in Boulder where the Rockies begin so dramatically is a pull too, so there are a lot of people living here now - and its seems to be becoming one of those points of good gardening you find in the States; Lauren probably has a lot to do with this, but fundamentally it probably comes down to Panayoti Kelaides, at the Denver Botanic Gardens, a name I have known for years. So nice to meet him at last, for his reputation is truly formidable; an expert on alpine flora, and on natives of the region, and on getting them into cultivation.

So is this just vicarious enjoyment of an exotic garden style? Or can I take something home from here. Probably not me personally, from soggy Herefordshire, but the drought-tolerant look and lessons are a great inspiration for drier parts of the country. It is also useful to see an extreme version of a situation you are familiar with - it somehow emphasises new possibilities and ways of thinking.

Lauren and Scott's book Plant Driven Design, was published by Timber Press earlier this year, and was one of 2009's best garden books.