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April 2013

What’s this scilla doing in a wood in New York?

Siberian squill, Scilla siberica, growing in Sullivan County, NY. Image ©GardenPhotos.comNosing around in the spring woods yesterday, near the east branch of the Callicoon Creek in Sullivan County, NY, I spotted a speck of sparkling blue, amongst fresh foliage and the flowers of Dutchman’s breeches, Dicentra cucullaria. Seemed odd. Took a closer look, and it was a scilla. There were a few leaves and three stems with one flower on each.

The map on the USDA Plants website reveals that the Siberian squill, Scilla siberica (left, click to enlarge), has been found in seventeen north east states but, according to the New York Flora Atlas, never before in Sullivan County. The little trail is part of the Stone Arch Bridge Historical Park, but few visitors pass this way. A quick check with the Pennsylvania Flora Project reveals that it’s been recorded in three places here in PA (For Brits: Pennsylvania is the size of England.).

It’s not native, it comes from Russia. So what’s it doing in a wood in New York? The nearest house – not, it’s clear, occupied by a keen gardener - is hundreds of yards away. In more than ten years I've only once heard of the creek flooding the area in which it was growing, so a flood is unlikely have dumped a bulb. So where it come from?

One flower was already developing its seed pod, which had weighed down the stem so that the pod was resting on the ground. That’s one way for the seed to spread a few inches. It’s growing about 10ft/3m from the narrow trail so seed arriving on footwear seems unlikely.

I often take a walk along this trail in spring, and have never spotted it before. Although the flowers may only last a few days, in hot weather - it can easily reach 70+F/21+C in April.

So I wonder how it got there…?

Nepeta ‘Walker’s Low’ – why the unsuitable name?

Nepeta (catmint) 'Walker's Low' - not really low at all. Image ©Walters GardensWorking on an article about catmints, Nepeta, recently it suddenly struck me: Why does Nepeta racemosa ‘Walker’s Low’ (left, click to enlarge) have such an unsuitable name? You’d never describe it as “low” growing.

Checking what I said in my own book – my big fat Encyclopedia of Perennials – I see that I gave the height as 24in/60cm. When the Chicago Botanic Garden reported on their trial of nepetas back in 2007, they gave it 30in/75cm. America’s Perennial Plant Association, when it gave ‘Walker’s Low’ its Perennial Plant Of The Year award in 2007 gave its height as 24-36in/60-90cm.

Of course it tends to flop, rather elegantly in fact, and if trussed up to keep the stems vertical would be even taller – though perhaps less appealing. But how did a plant that can reach 3ft/90cm in height come to be called “low”?

I’ve been rooting around trying to find out for the last few weeks – and have not come up with a definite answer. Can anyone help?

It’s often said to have been raised in Ireland or named for an Irish garden, but the leads turn out to be dead ends. The garden writer Jane Taylor (author of The Shady Garden, Fragrant Gardens and of the very useful Drought Tolerant Plants) has been cited as having discovered the plant – but I’ve been unable to contact her. [If anyone has contact details, please email me privately.]

Just to emphasize the fact that ‘Walker’s Low’ is not a short plant – we now have a dwarf version, reaching just 15in/38cm. It’s called Junior Walker (‘Novanepjun’) and was created by “gamma-ray mutagenesis” – tissue-cultured plants of ‘Walker’s Low’ were treated with gamma radiation, then grown on, planted out and assessed. One neat, bushy and prolific plant was chosen, give the code name ‘Novanepjun’ and the selling name of Junior Walker – acknowledging the saxophonist of that name, leader of the Tamla Motown band Junior Walker and the All Stars. It’s just starting to appear in the US, not yet in the UK.

So – does anyone have any ideas - or better still facts! - about how ‘Walker’s Low’ got its name?

* My article on nepats appeares in the May issue of the Royal Horticultural Society's magazine, The Garden.

Book Bullet: Spring Wildflowers of the Northeast by Carol Gracie

SpringWildflowersJacket500This is a fantastic book.

Discussed in rich but readable detail, and profusely illustrated, are thirty of those beautiful and fascinating spring flowers which mark the passing of the snow and ice and the sudden rush of new growth – and not just in the north east, but over much of the country.

Plant by plant, from baneberries to wild ginger, centuries of scientific research are brought together with decades of enlightened personal observation to present detailed accounts of some of our favorite plants. But not just descriptions, far from it. The ways in which these plants fit into their botanical families, their relationships with their habitat, their pollination, their seed dispersal, their medicinal and other practical uses – it’s all there.

And here’s the thing: we know we can trust its combination of science and experience not only because it’s clear that it’s written by a scrupulous fanatic! But also, from her years as a tour leader at the New York Botanic Garden answering the questions of visitors – interested, of course, but not necessarily knowledgeable – Carol Gracie knows how to present her fascinating material in a way that scientists will respect, and everyone else can understand (with occasional help from the excellent glossary).

The book is also packed with wonderful pictures. In fact my only criticism of the book is that, in places, there are too many squeezed on to the page. I don’t think there’s a dud amongst them, but sometimes the page is just too full.

I first looked at entries on plants I’d recently researched myself including skunk cabbage, Symplocarpus foetidus, where her account of the plant’s mechanism for generating so much heat in its early flowers that it can melt snow and keep insects cozy includes an important detail that I’d missed! And I was thrilled to discover that it’s the box turtle, wandering up to 60m a day, that not only distributes seeds of may apple, Podophyllum peltatum, but through keeping them in its digestive system for a week while it wanders also greatly improves their germination.

So… whether you grow these plants in the garden or simply admire them on rural (or sometimes urban) hikes, I’m sure you’ll find this book fascinating. If you need more superlatives, just ask.

Spring Wildflowers of the Northeast by Carol Gracie is published by Princeton University Press.
  • The habits and habitats of thirty familiar spring flowers revealed
  • Detailed but easy-to-read text
  • Huge number of exceptional pictures
  • Gardeners and wildflower enthusiasts will be fascinated
  • Not just for those of us in the north east US
  • Put it on the short list for plant book of the year


Choosing good seed-raised delphiniums

Delphinium 'Pink Punch' (New Millennium Series) is one of Terry Dowdeswell's top quality varieties. Image ©GardenPhotos.comIn general, gardeners have a very positive and appreciative feeling about delphiniums. Unfortunately, those decades of pleasure - centuries even - is often betrayed by the fact that most delphiniums found in garden centres and nurseries are so disappointing. The problem is that they’re raised from seed, and so few producers of delphinium seed are prepared to spend the time and trouble it takes to keep the quality high.

So we often find that plants of the old Pacific Giants Series (including ‘Blue Jay’ and ‘King Arthur’) and the dwarf Magic Fountains Series have gappy spikes, poorly formed flowers and may not even be true to colour. As I say, it takes a lot of time and effort to keep them true; this is expensive and when the cost is reflected in the price of the seed, many nurseries and home gardeners are reluctant to pay the extra. So we get what we pay for. The Guardian Series, in four colours, and the Centurion Series, in six colours, are more dependable than those old Pacific Giants Series and Magic Fountains but the seed is significantly more expensive.

In New Zealand, delphinium breeder Terry Dowdeswell has concentrated on quality. His New Millennium Series represents the best seed-raised delphiniums you can buy. They're outstanding in terms of the quality of the individual florets, the elegance of the spikes, and you can be confident that if they’re supposed to be blue, or purple, or white – then they will be, with none of the unexpected colors found in other varieties.

In the 2008 trial of delphiniums from seed at the RHS Gardens at Wisley, and in the earlier trial in 1994, the general quality of Terry Dowdeswell’s plants was very noticeably better than that of the more familiar Pacific Giants and Magic Fountains.So try them.

The easiest way for everyone to get hold of these New Millennium delphiniums is to order seed direct from Terry Dowdeswell.

* This is part of a piece entitled Buying Good Delphiniums which appears in the current issue of the Newsletter of the Ranunculaceae Group of the Hardy Plant Society. Anyone with an interest in hardy plants in the Buttercup Family (Ranunculaceae) should join. The second part, on delphiniums propagated from cuttings and tissue culture, will be posted here in June.

Botanical names really are easier than common names

Cleome hassleriana 'Violet Queen' - or Pink Queen 'Violet Queen'? Image ©Mr Fothergill's SeedsToday I’m working on a project that requires the plants I’m writing about to be organized alphabetically, by common name.

This quickly turns up two big problems:
1.    What is the correct common name for the plants I need to include?
2.    Some entirely different plants share the same common name.

In Britain, common names are used far less than they are here in the US – and very often they’re different. And in different parts of North America, different common names can be used for the same plant. So I turn to the USDA Plants Database, which gives common names for native and introduced plants, even for many rarely seen species.

I need to check Cleome. In Britain, we tend to call the various forms of that impressive tall annual Cleome hassleriana – well, we tend to simply call them Cleome… or perhaps occasionally Spider Flower. But, not very helpfully, Spider Flower is a name also used for those Australian shrubs, Grevillea. OK, confusion is unlikely, but if the plants are listed by common name, the varieties of Cleome and Grevillea - two entirely unrelated plants – would be listed together as Spider Flower as if they were forms of the same plant. Not helpful.

But the USDA Plants Database turns everything upside down by revealing that in North America the common name for Cleome hassleriana - is Pink Queen. Now, there’s a popular old heirloom variety of Cleome hassleriana called ‘Pink Queen’. So we’re in the bizarre position of having to list this plant as Pink Queen ‘Pink Queen’… And not only is there also Pink Queen ‘Purple Queen’ but Pink Queen ‘White Queen’ and Pink Queen ‘Violet Queen’. Makes no sense at all.

Botanical names may sometimes turn out to be tongue-twisters – but Pink Queen ‘Purple Queen’? I don’t think so.