Books

Book Review: Lathyrus - The Complete Guide

Lathyrus latfolius 'Blushing Bride'
Lathyrus latifolius is one of the most popular of hardy perennial Lathyrus species. This is 'Blushing Bride'.

This is the first book to cover the whole of the genus Lathyrus, and not focus only on sweet peas. And a very fine piece of work it is.

Lathyrus: The Complete Guide, by Greg Kenicer and Roger Parsons, Plant Heritage National Collection holders, is indeed comprehensive. It covers all 150 Lathyrus species, 1,200 cultivars, and there’s also a directory of 450 breeders and companies associated with Lathyrus and this fat 500 page book is gloriously illustrated throughout.

Everything from the evolutionary origins of Lathyrus to recent taxonomic revisions are discussed, and the latest classification is clearly set out with the genus presented in its constituent groups so that relationships between species are easy to understand.

Many unfamiliar species are included, those of horticultural interest or potential being given more space than the less noteworthy species. Following the latest research, the garden pea, formerly Pisum sativum, is now included in Lathyrus as L. oleraceus. However, with differences in opinion between the botanic community and the agricultural community this may not prove to be the last word on the subject. However, the authors have taken the wise decision not to list or illustrate the many many garden pea cultivars.

Lathyrus-The-Complete-Guide-FullCover900As with other books in this impressive series, discussion of the cultivars is separated from descriptions of the parent species and there is also an extensive table usefully summarising the features of all the cultivars discussed – as well as a separate descriptive list of almost all the cultivars offered for sale in the last five years. This results in entries for many cultivars in three different places. Personally, I find this irritating but I can see that this approach combines comprehensiveness with an economy of space.

The book is, of course, dominated by the sweet pea with detailed discussions on its origins and recent development and with hints of interesting hybrids on the way. The whole story is clearly set out, bringing in detail of developments around the world to provide a full picture.

In spite of the technical nature of some of the material the book is an easy read, elegantly laid out and the photography ensures that even the less flamboyant species look tempting.

This impressive new work clearly relegates my own book on sweet peas to a dusty corner of the bookshelf!

“An elegantly presented, comprehensive and accessible presentation of everything you’d want to know about sweet peas and their annual and perennial relations.”

Lathyrus: The Complete Guide by Greg Kenicer and Roger Parsons is a Royal Horticultural Society Monograph. £40.

Others in the Royal Horticultural Society Monograph are: Colchicum, Hedera, Kniphofia and Wisteria.

Order Lathyrus: The Complete Guide for delivery in Britain from the RHS.

Order Lathyrus: The Complete Guide for delivery in Britain and around the world from the Natural History Book Service.

Order Lathyrus: The Complete Guide for delivery in Britain and around the world from Summerfield Books.


News from northern travels

Dahlias protected from earwigs with organza bags
Dahlias protected from earwigs with organza bags at Cloudberry Flowers.

I’ve been on a little jaunt. A week in the Scottish borders and in Northumberland making horticultural stops – not to mention startling fellow drivers by singing sea shanties as we were stuck in traffic.

I stayed with my old friend, the award-winning botanist Phil Lusby, author of Scottish Wild Plants: Their History Ecology and Conservation, and his weaver wife Ellie. Sadly, amazon has priced his splendid book more than a little high (£77.99), although they also say that it was published in 1679 so what do they know! Oh, wait. There's a revised edition at a proper price: £11.43. That's more like it.

I learned some very interesting background on the genetics of native roses, which I’ll come back to here another time, and we found a puzzling variegated honeysuckle in a hedgerow. Puzzling, because there was so much of it: not just a single shoot or a single plant – there was masses of it. I suspect virus.

Lonicera periclymenum with mysterious variegation
Lonicera periclymenum with a mysterious variegation growing in a Scottish hedgerow

We had a lovely visit to Cloudberry Flowers in Peebles, one of the new breed of cut flower growers supplying fresh, locally grown, sustainably produced flowers for local customers. Catherine Duncan’s cutting gardens seem steadily to be taking up more of the acre of garden that surrounds the house, encroaching on the lawn.

I was especially taken with the ghostly dahlias (at the top): organza bags keeping out the dreaded earwigs.

In Northumberland I visited Halls of Heddon, celebrating their centenary this year, and from whom I and my friends order dahlias and chrysanthemums. Apart from the fine quality of their plants, customers who’ve had occasion to use their customer service cannot speak too highly of the response.

I always enjoy seeing plants on trial, lined up in rows, side by side, and that’s what you’ll find at Halls. It makes it so easy to compare varieties and I guarantee you’ll be delighted when come across a treasure that you didn’t know. I was very taken with ‘Blyton Everest’, a very tight, white small decorative with lavender tints in the centre.

Of course, we can’t all get to visit but their website is easy to use and comprehensive.

Halls of Heddon display garden
The Halls of Heddon display garden

In Northumberland I also paid a visit to another cut flower grower, Kate Norris at Northumbrian Flowers https://northumbrianflowers.co.uk/ near Hexham. Busy with weddings, there’s a flurry of brides desperate for flowers as all the pandemic-postponed weddings are back on the calendar, the cutting garden was nevertheless looking very prolific.

Rudbeckia 'Sahara' at Northumbrian Flowers
Rudbeckia 'Sahara' at Northumbrian Flowers

Her bed of Rudbeckia ‘Sahara’ was impressive – such lovely tones – and there was bed after bed of helichrysums in separate colours. Kate had also recently planted more woody plants for cutting, especially hypericums, so I was able to recommend some physocarpus and point her to me my earlier blog post.

And finally, apart from enjoying the magical Borders scenery, I also got to spend a couple of evenings in a delightful little shopfront pub in Newbiggin-by-the-Sea on the Northumberland coast. The Ink Spot is only open a few hours a day, three or four dys a week, there’s no loud music, no food – just cheerful locals and their dogs enjoying drink and conversation. Seats, at a guess, eighteen. Marvellous. I’ll be back.

TheInkSpot


Book Review: RHS Weeds

RHSWeedsFixed

We all know about weeds. We pull them out, we throw them on the compost – and then we do it all over again. And again. But weeds are far far more than never ending irritation and fodder for the compost heap as this elegant little book reveals. They’re simply fascinating, as RHS Weeds by Gareth Richards proves.

Looking closely at fifty plants that most of us would rather not have in the garden, we learn why they succeed, why they’re difficult to eradicate and also why we should admire them.

I have to say, though, that throughout this book there’s a definite feeling of support for the underdog. The more that Japanese knotweed or Himalayan balsam or ragwort is added to lists of banned weeds, the more Gareth feels the urge to remind us of the plants’ good qualities and the intriguing associated stories.

He airs his respect for Japanese knotweed, pointing out that bees love its generous late season nectar supply; he explains how the toxins that make ragwort so unpalatable, indeed poisonous, to cattle are passed on to the luridly striped cinnabar moth caterpillars that feed on its leaves; he notes the irony of Spanish bluebells being weeds in native bluebell woods, while native bluebells can be weeds in the garden.

Setting the tone for the whole book, in the very first entry, Gareth sets out his admiration for the sycamore, explaining how it behaves in the same way as native forest trees and fits well, visually, into the British landscape. Rather than be derided, sycamore should be welcomed as a replacement for the elm and ash that have been laid low by disease. What’s more, it turns out, sycamores support a greater mass of insects than oaks.

Clearly, Gareth has a rich understanding of what he calls these “vagabond plants”, these plants in the wrong place, yet this impressive appreciation is passed on to us in a very readable style, helped along by the beautiful historic botanical illustrations. So, when we’re finished heaving out brambles, we can relax with a cup of pineapple weed tea, and nurse our wounds as we discover why it is, exactly, that the bramble stems, and even the backs of the leaves, come with so very many vicious thorns.

I know it’s a cliché to say it, but in this case it’s actually true: this is a book that all gardeners will enjoy.

RHS Weeds by Gareth Richards is published by Welbeck.

Declaration of interest: the author is a friend and the book was supplied free of charge by the publisher.


Trialling New Zealand sweet peas

Sweet peas (l-r) 'Bix', 'Pink Nines' and ‘Enchanté’
Sweet peas (l-r) 'Bix', 'Pink Nines' and ‘Enchanté’

Dr. Keith Hammett is the world’s leading sweet pea breeder. I’ve always been a big fan of his varieties, and he’s made so many important steps forward including integrating the most recently discovered species – the red and yellow Lathyrus belinensis - into his breeding work.

This year I trialled seven of his varieties, some of which I’ve never grown before, and I was especially pleased with four of them. Just to be clear, seed was sown in late winter, they were grown in ordinary garden conditions, on a wigwam of bamboo canes, in a corner of the cutting garden just round the corner from here at boutique florist Foxtail Lilly.

‘Bix’
This has been outstanding, not so much for its productivity but for its wonderful cream colouring with the strong rose pink picotee.

‘Enchanté’
One of the few tri-coloured sweet peas, with pale cherry red standards, white at the base, and pale mauve-blue wings opening from yellow buds. A delightful soft combination.

‘Enigma’
I was really looking forward to the vertical magenta-pink stripe through each pale pink standard but found it much less clear than I expected. I’ll give it another try next year, in better conditions.

‘Nuance’
This is a two-tone pink with darker standard and paler wings, very pretty but not as striking as I’d expected.

‘Pink Nines’
Nine flowers per stem – yes really! I loved this for the long life of each stem, provided by its eight or nine flowers. We need this in other colours.

‘Route 66’
Gorgeous, nicely frilled, pink and white bicolour that was taller and more vigorous than any other sweet pea in the cutting garden. ‘Little Red Riding Hood’ is similar, but bright red and white.

‘Turquoise Lagoon’
An extraordinary combination of pinkish mauve maturing into soft turquoise blue. Very pretty in posies with pinks.

I’ll definitely be growing ‘Bix', ‘Enchanté’, 'Pink Nines’ and ‘Route 66’ again, and I suspect that the others would be more effective with better treatment.

Sadly, since Brexit, Keith is unable to send seed from New Zealand to the UK. However, many of his varieties are available in the UK from English Sweet Peas and from Mr Fothergill’s. In North America try Sweet Pea Gardens.

And you can find out more about Keith’s sweet peas here.

Over at the award-winning Blackberry Garden blog, my friend Alison Levey has also been growing these sweet peas from New Zealand. Check out her report here.

I’m still waiting for my copy of the new RHS monograph on Lathyrus by Royal Botanic Garden, Edinburgh, botanist Greg Kenicer and Plant Heritage National Collection holder Roger Parsons. Of course, it includes sweet peas. When it finally arrives, I’ll be discussing it here… It's arrived! It looks stupendous. Review coming...


Book Review: The Joy of Dahlias

The Joy of Dahlias by Katja Staring, Linda van der Slot and Marlies Weijers
The Joy of Dahlias by Katja Staring, Linda van der Slot and Marlies Weijers

I like books. I’ve written quite a few, reviewed more and have a house full of them but sometimes the publishers just leave me baffled.

Dahlias are the flower of the moment so when I saw that The Joy of Dahlias by Katja Staring, Linda van der Slot and Marlies Weijers (Terra) was out I asked for a review copy. But, immediately, I saw that something was amiss.

The paper is not coated, slightly shiny, as it is in most books where the pictures are important. So, instead of gleaming off the page, the ink is absorbed, just a little, and the result is dull, no sparks, which wastes the original images; I’m sure they’re better than they look in the book. Presumably the uncoated absorbent paper is less expensive.

The authors, all flower growers themselves, have enlisted the help of a large number of other growers who share their dahlia wisdom, although there’s no list or index of who they are (another thumbs down for the publisher).

Authors are at the mercy of their publishers. Most published gardening authors will have a tale of a change of plan that never filters through to the writer at the keyboard, a deadline mysteriously brought forward, a title changed with no consultation. The result is that slips are missed and things end up on the page that shouldn’t.

I roared when I read this: “Since the beginning of time, the dahlia has grown as a wild plant in the highlands of the area which we now call Mexico.” Hah! “Since the beginning of time!” Oh, please. “In the beginning God created the dahlia.”?!

It’s the publisher’s job, and particularly the copy editor’s job, to tell the authors: “You can’t say that.”

And just to be clear: I’d be hugely embarrassed if some of the things I’ve sent to publishers in a mad hurry had actually made it on to the page.

There are more, but enough’s enough. It’s a very contemporary book, the design is sparky, and all the information presented in bite-sized nuggets by a wide variety of dahlia fanatics. It’s a dahlia book for the Instagram age - and that’s not a criticism at all, it’s praise.

But, again, the publisher has also not helped by pricing the book at £30. OK, you can get it for less on amazon, of course, but Discovering Dahlias by Erin Benzakein, which I reviewed here back in May, is almost exactly the same size, the pictures pop off the page, we know we can trust every word – and its publisher’s price is £18.99.

This could have been a much better book if the publisher had helped the authors as it should have done. And can we please have an index to more than just the recommended varieties?

The Joy of Dahlias by Katja Staring, Linda van der Slot and Marlies Weijers is published by Terra.

 

Declaration of interest: the book was supplied free of charge by the publisher.


Book Review: The Secret Lives of Garden Bees

SecretLivesOfGardenBees900

This week is Bees’ Needs Week, an annual event coordinated by the Department for Environment, Food & Rural Affairs and involving charities, businesses, conservation groups and academic institutions to raise awareness of bees and other pollinators. So what better time to remind you about this book?

I had no idea there were so many different kinds of bees! The Secret Life of Garden Bees by Jean Vernon (published by White Owl) really opened my eyes to the vast variety of these endearing and invaluable creatures. Two hundred and seventy six species in Britain alone.

Honeybees: yes, of course, I know about them. These are the ones everybody gets so worked up about. But they’re probably the ones least in need of protection - after all, there are beekeepers all over the country whose aim is to look after them. There are also the bees that burrow into the mortar in the front wall of my old stone house: yes, I know about them.

But I had no idea about, for example, the ivy bee which doesn’t emerge from its below ground nests until September when the first ivy starts to flower. Or Britain's rarest bee, the shrill carder bumblebee, known only from a few places scattered across southern Britain.

This is an eye-opening book and one thing that Jean Vernon does very well, as she guides us through a world that really is secret to most of us, is to present information that could be seen as off-puttingly technical in easy accessible language. It's crucial for writers aiming to engage readers with new and detailed material to carry them along, to present no barriers. Some resort to being superficial - but what's the point of that?

Reading The Secret Lives of Garden Bees we can absorb the information in an enjoyable way without feeling overwhelmed.

  • Declaration of interest: the author is a friend, and the book was supplied free of charge by the publisher.
  • A shorter version of this review appeared on Facebook in July 2020.

Book Review: Peonies by Claire Austin

Peonies by Claire Austin
Peonies is the new book by Claire Austin

It’s peony season and we have a new book on peonies to savour. Written and photographed by renowned peony expert Claire Austin - her nursery lists more peony varieties than I could count – she doesn’t just describe her choice from the thousands of varieties she’s seen and grown over the years. No, she adds the fruits of her insight derived from decades of experience. (Well – enough decades to soak up the experience but not so many decades that… I’ll stop digging.)

The book is, basically, Claire’s choice of peonies, described and illustrated. We know we can trust her choice, and there’s no tricky botanical language in the text to trip us up. In fact I think that she sat on a stool in front of each variety and simply described what she saw. The best way.

But there’s more. So, apart from giving us the description of each plant we learn, for example:
‘Bunker Hill’ “Unlike many red lactiflora blooms, the petals don’t deteriorate quickly when the flower is cut.”
‘Emma Klehm’ “A useful plant for those who want a very late-flowering variety.”
‘Little Medicine Man” has flowers that are small “but produced in great numbers on stiff red stems”.
‘Marie Lemoine’ “Sadly, wet weather can spoil the flowers.”
‘Shirley Temple’ “blooms freely in a partly shaded spot”.’

She also notes, for each variety, whether or not it needs staking and the strength of its scent and lists more than two dozen varieties that she especially recommends for cutting.

Before we come to the descriptions and illustrations that make up most of the book, we have Claire’s advice on growing peonies, a summary of their development over the centuries, and a fascinating account of her own history with these everlastingly tempting perennials.

And I’m pleased to say that she slays the myth about moving peonies: “There is a long-held but totally unfounded gardening belief that peonies cannot be moved.” Got that? “unfounded”.

“Peonies have few ailments,” Claire continues. True enough. But a cut flower growing friend asked me just a couple of days ago why her white peonies were spoiling the purity of their colour with faint red flashes. I had no idea, so I hoped Claire’s book would help. But no luck.

So I’m very happy to have this book on my shelf, to enlighten me – and to steal from – whenever I need. Just one thing: the design is, well, a little bit dull. Modern plant books, including the excellent RHS Horticultural Monograph series and Discovering Dahlias that I reviewed here recently, inspire interest partly because of the elegance of their design. I see no designer is credited on this book. Claire should think about hiring a specialist designer next time.

  • An unimpeachable choice of the best varieties
  • Every variety illustrated
  • Descriptions based on personal experience
  • Thoughtful insight into each variety’s qualities
  • Readable and without reliance on botanical language
  • Design could be more stylish

“Dependable peony advice from our leading expert.”

Peonies by Claire Austin is published by White Hopton Publications at £25. Order a copy from Claire Austin’s Hardy Plants.

 

 


Discovering Dahlias

Discovering Dahlias by Erin Benzakein
Having been despised as garish and – frankly - the flowers of the lower classes for decades, the rehabilitation of the dahlia began with the very definitely not-at-all working class Christopher Lloyd using them extensively in his garden at Great Dixter, in Sussex.

The dahlia has never looked back and the books have followed. There are three more recent and upcoming dahlia books that I’m going to discuss here over the coming weeks and the first is Floret Farm's Discovering Dahlias by Erin Benzakein.

I’m a big fan of Erin Benzakein. She runs Floret Farm in Washington State and has done more than most to popularise the idea of locally grown, non-industrial cut flowers. She’s gone from a one-woman enterprise to planting twenty acres in just a few years.

I really enjoyed her first book, Floret Farm’s Cut Flower Garden, and reviewed it here in 2017, and now comes another.

This is an inspiring book, but not without its faults. The photography, by Erin’s husband Chris, is immediately striking not just for the awe inspiring views of the cutting fields but for the delightful detail revealed in the close-ups.

The catalogue of Erin’s recommended varieties is arranged by colour and there are, for example, five pages of dahlias in peachy shades – thirty varieties in all – and all shown in huge bunches held by Erin in front of her ubiquitous blue shirt and described in detail. It’s all so tempting that wants lists soon extend to a second page of back-of-the-envelope scribble. And this where things begin to become less convenient.

There’s no list of suppliers of dahlia tubers and/or cuttings in the book. Instead, we’re directed to the Floret Farm website where we must sign up to receive the “Discovering Dahlias Bonus Materials” by email. A great way to collect email addresses. This arrives promptly and includes descriptive details (not just a name and a link) of twenty three American dahlia specialists, seven in Canada, four in mainland Europe - but only two from the UK. Not good.

Three hundred and sixty varieties are included in the directory. I presume they’re all available from American suppliers – frankly, I just don’t have time to check. But I looked up all those peachy varieties in the latest edition of the RHS Plant Finder – which lists all the plants available from British and Irish nurseries, 81,000 of them. Eight of the peach varieties are listed with at least one supplier – twenty two are not listed at all. And if you want to check Erin’s thoughts on varieties you already have on your wants list – forget it: there’s no variety index.

The practicalities are very much based on experience in Washington State and British growers, and growers in other parts of North America, will need to adapt. She assumes you’ll root your cuttings under lights, for example.

So we end up being inspired and tempted and mad keen to add to our dahlia collection – or start one. American readers can, I assume, spark their enthusiasm into action. British and Irish enthusiasts will have quite a lot of work to do.

  • Beautiful and inspiring
  • A tempting choice of varieties revealed
  • Paper and print quality excellent
  • Extremely well priced
  • Few recommended varieties available in Britain
  • Skimpy pest and disease coverage
  • Sad absence of a variety index

“Beautiful to look at and genuinely inspiring, but it could do more to help turn inspiration into achievement.”

Floret Farm's Discovering Dahlias by Erin Benzakein is published by Chronicle Books.

Order Floret Farm's Discovering Dahlias in the UK

Order Floret Farm's Discovering Dahlias in North America

 

Discovering Dahlias by Erin Benzakein - the first peachy pages


Grow, Cut, and Arrange

A spring arrangement from Floret Farm’s Cut Flower Garden by Erin Benzakein (with Julie Chai)
Our gardens are full of flowers and we like to have them in the house too but so many of us fail to make the best of our cut blooms. Which are the best flowers to grow for cutting at home? How should we grow them? How should we treat them to ensure they last as long as possible? How should we arrange them for the house? An inspiring new book by the owner of Washington State’s Floret Flower Farm aims to answer all these questions for gardeners on both sides of the Atlantic.

Floret Farm’s Cut Flower Garden by Erin Benzakein (with Julie Chai) is a lovely looking book. Organised by season, the challenge has been to adapt large scale commercial techniques to the needs of home gardeners. Few of us grow on the scale of Erin’s farm and none of us have the experience of growing so many different flowers. She wants us to do more than simply cut what we have plenty of and stick them in a jar.

Floret Farm's Cut Flower Garden: Grow, Harvest, and Arrange Stunning Seasonal Blooms by Erin Benzakein and Julie Chai is published by Chronicle Books at $29.95/£21.99.Which are the best? Erin does not say “grow this” or “grow that”, she simply covers a huge variety of flowers and leaves it up to you, from roses and sweet peas to flowering carrots and hellebores. However, I was very surprised to find that calendulas, annual asters and Shasta daisies are left out entirely. I’ve been enjoying one or the other – and sometimes all three – in a jug on my kitchen table for months.

How to grow them? The climate in Washington State is closer to the climate of the UK than it is to the climate in much of the rest of North America so although her cultural advice is excellent, growers in many parts of the US will have to adapt to their own conditions. I’d never heard the surprising advice to leave dahlia tubers in the ground for the winter but to divide them every year because otherwise they'll become too heavy to lift! Not in Britain!

How to make them last? There’s excellent advice on caring for cut flowers and for every flower covered there’s an invaluable Vase Life Tricks section which is perhaps the most universally valuable part of the book. This is the part I’ve used the most.

How to arrange them? Each seasonal section includes very useful step-by-step illustrated guides on how to create a series of arrangements in a variety of styles. Oddly, the individual pictures are quite small while a great deal of page-space remains empty. Seems a waste...

This is an elegant and very useful book, full of valuable advice presented attractively. But the fact remains that there’s no one book that provides all guidance we need. And no asters?!

Floret Farm's Cut Flower Garden: Grow, Harvest, and Arrange Stunning Seasonal Blooms by Erin Benzakein and Julie Chai is published by Chronicle Books at $29.95/£21.99. 

 

                                     


Ivy: Friend or Foe?

Hedera colchica 'Dentata Variegata'

Ivy is a plant that divides opinions. Attractive foliage, good for wildlife, cools buildings… Invasive, ruins walls, harbours pests…. Research and opinion on all these issues has been in the news increasingly in recent years and now the most comprehensive book on ivies ever produced has been published by The Royal Horticultural Society.

Hedera: The Complete Guide by Hugh McAllister and Rosalyn Marshall is exactly that – the complete guide. With more than four hundred pages, and impressively illustrated in colour throughout, this is the second in the RHS Horticultural Monograph series which began with last year’s excellent book on kniphofias.

This is an attractively designed book – far more appealing than most gardeners expect from a serious plant monograph even though the predominant colour of ivies is, well, green. All the species are described in detail, but not in torrents of baffling technical language; two hundred cultivars are illustrated and described, and the fat descriptive checklist covers all the other names that have ever been used, over two thousand of them.

One very useful feature of the book is its use of the Pierot system of classification. This was created by Suzanne Pierot, the first President of the American Ivy Society, in the 1970s and divides ivies into nine convenient groups based on easily-seen features of the foliage. Brits are largely unfamiliar with this approach so its use in this book should help it stick.

HederaBookCover9781907057731But what does the book have to say about those pros and cons?
Attractive foliage? Obviously.
Good for wildlife? Yes. “Ivy berries are eaten by at least 17 species of bird in Britain indicating the importance of this plant group for the support of vertebrate wildlife…. They have a high energy, though low protein, content and form a large part of the diet of several species at this time of year (winter).” “The autumn flowering of ivy provides nectar for a wide range of invertebrates at a lean time of year.” Not to mention ivy as a valuable nest site.
Cools buildings in summer, warms buildings in winter? Yes. “Measurements on ivy-covered stone walls across several historic sites in England… showed that an ivy covering resulted in cooler walls in summer and warmer walls in winter.” “Recent research on the climate of southeast UK… suggests that a 21-37% reduction in winter heating could be achieved.”

Invasive? Sometimes. While most ivies can develop vigorous growth in their native habitats, it is almost always H. hibernica that causes problems as a non-native plant. “All ivies need not be banned in climates where invasive ivies are a problem. There are enough dwarf, miniature and slow-growing cultivars of H. helix to provide a good range of safe and attractive plants for indoor and outdoor use.” In my Pennsylvania garden, as soon as an ivy shoot penetrates the deer fence the deer eat it.

Damages walls? Sometimes. “Any increase in relative humidity due to wall plant cover is offset by lack of rain reaching the building.” But: “ivy can root into weakened historic walls or buildings, and can lift blocks of stone off walls” and also damage walls built and pointed using soft mortar.

Harbours pests? Sometimes. Ivy is attacked by viburnum scale which also attacks Viburnum tinus. “In pots, by far the most serious pest of ivy is vine weevil” – which attacks a wider range of other plants. I’d be interested to know if outdoor ivy has a role as a reservoir of vine weevil infestation.

This is an impressive book by one of our most seasoned horticultural taxonomists and a relatively young recruit to the RHS botany team. The RHS has more in the series on the way, I look forward to the series building into an invaluable resource.

Hedera: The Complete Guide by Hugh McAllister and Rosalyn Marshall is published by the Royal Horticultural Society at £40.00/$53.45.

You can read more about ivies in gardens and in the wild in these Transatlantic Gardener posts.
Ivy is not always a menace
Ivy reveals how nature is nuanced
Ivy goes green