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.

Sunflowers: Fake double pink and what the seed actually produced

Back in the spring I saw an ad on Facebook for pink sunflowers. The variety was said to be ‘Pink Pooh’ and, at first sight, the fully double pink flowers looked quite convincing. If it was a Photoshop job then it was well done. And that, of course, was exactly right – it was a well done Photoshop job. You can see it above.

My friend Alison Levey over at The Blackberry Garden blog checked the same Facebook ad and we decided to do a little test. Alison ordered some seed, sowed it, potted up the seedlings and then passed three of them on to me.

A few days ago Alison reported what she discovered and just over a week ago the first buds on my three plants opened. As you can see, above, each plant produced a perfectly nice, yellow flowered, single sunflower: an unbranched stem with just one flower at the top – it’s probably one of those varieties grown increasingly on a farm scale for bird seed.

But not a double pink. Are we surprised? Not really.

And it’s not just pink sunflowers. There are “rainbow” tomatoes (below) with blue, purple, puce and buttercup yellow fruits all on the same truss not to mention multicoloured tulips (also below) seen nowhere on the planet outside websites trying to sell us the doctored images.

So, in the words of every shopping and consumer rights expert across the world: “If it looks too good to be true, then it probably is.” In these cases, we can scratch out the “probably”. Don’t waste your money.

An image of fake 'Rainbow' tulips offered for sale.

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...

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.