I arrived back in Pennsylvania the day before yesterday, after a very trying flight from London I have to say, to find judy hard at work in the garden. She was protecting the fresh new growth of so many perennials and shrubs against the forecast frost by spreading old sheets over the plants. It had worked in previous years, and for the previous few days, so she was at it again.

Every old sheet in the house was pressed into service, in fact so many sheets were dragged out that I feared my first night back would be spent in a sleeping bag. Anyway, it worked again. But as the garden expands I think we’re going to have to order a roll of fleece (garden fabric, to US gardeners).

As it happens, just a few days earlier I’d taken a look at the new South Africa Landscape being installed outside the British Museum in Bloomsbury, central London. And with frost forecast there too, they adopted the same approach. In spite of global warming and the advantageous microclimate of central London, Bloomsbury is still not quite like that of South Africa. That’s not to say that a taxi was sent round to the Director’s house to roll him out of bed and collect his bed sheets. The Royal Botanic Gardens Kew (Kew Gardens to most of us) were planting the display and used the same fleece we should be buying for our Pennsylvania garden.

The idea of the planting at the British Museum, by the way, is to highlight the extraordinary diversity of plant life native to South Africa’s Cape region and to make connections between plants, people and the objects on display in the museum’s Africa galleries. Sounds fascinating. The display opens on Thursday.

Find out more about the South Africa Landscape at the British Museum.

As we thoughtlessly manipulate our environment, plants react.

So much salt has been spread on British motorways in recent years, with the aim of ensuring that the danger of ice on the roads is eliminated, that the soil in the central reservation (“median” to American readers) has become much more like a coastal habitat. And the result is that a native coastal plant is now a familiar sight on motorways all over the country.

Danish scurvy grass, Cochlearia danica, was once restricted to seaside habitats. Crawling round London’s orbital M25 again the other day, I shimmied into the outside lane as the traffic crawled along and took a look at what was growing along the central barrier – and I found miles of Danish scurvy grass.

This is a low and spreading member of the cabbage family with slightly succulent stems and leaves, and four-petaled white flowers. It’s bursting with Vitamin C and, as the name suggests, was used to combat scurvy. It was even recommended to sailors by Captain Cook!

Most of the plants had white flowers, there were occasional pinkish-flowered plants. But for many miles Danish scurvy grass, Cochlearia danica, was almost the only plant to be seen. It will be interesting to see if other coastal plants like beetroot and cabbage and sea thrift follow Danish scurvy grass as it spreads around Britain’s roads.

For more on Danish scurvy grass, Cochlearia danica, take a look at the Wild Flowers of the British Isles website.

Every now and then, here on the Transatlantic Plantsman blog, I highlight a mail order nursery which illustrates its plants with pictures which are – how shall we say – unrealistic… Check out one of them.

Now here’s a bold piece of signage from the Royal Horticultural Society plant centre at Wisley in Surrey.

The sign says the bench is loaded with a lovely perennial forget-me-not called Myosotis My Oh My (‘Myomark’). In fact the bench is bursting with (some very appealing)… Pieris. Slightly disconcerting that no one seems to have noticed this.

About a week ago, we went to check out what our local Pennsylvania Home Depot, just to see what plants they had in for the new season. (For British readers: Home Depot = B&Q, only much bigger).

The first thing we noticed as we approached the entrance was this pallet of forsythia. About 5-6ft/1.3-1.8m) high, and grown in the open ground with their roots wrapped in sacking (balled and burlapped, as the US has it), they were priced at $22.98 ($24.36 including local sales tax). That’s £15.85 in British money.

Interestingly, they were marked as “local grown”. There’s a small but growing inclination in the US in favour of food, plants and other products being grown locally. Their source was given, these forsythias came from about 160 miles away. Not very local by British standards, of course.

Then yesterday I was at the plant centre at the Royal Horticultural Society’s garden at Wisley, south of London. Not entirely similar, of course, but I took a look at their forsythias. Theirs were in pots, unlike the Home Depot ones they were named (‘Weekend’) and they were about 18-24in/45-60cm high. They were priced at £9.99 (including tax), that’s $15.36. So they were a about a third of the size – and two thirds of the price. Not sure how local they were.

Two things struck me about this. It would be good if British gardeners could buy forsythias that size at a reasonable price. But, also, that the Home Depot forsythias were probably too cheap.

Next time I pass a garden centre, I’ll pop in take a look at their forsythia.

On Friday I'll be lecturing to the Staffordshire Group of the Hardy Plant Society.

My theme? "Hellebores and Friends" - I'll be giving an overview of our favourite hellebores, then showcasing the many winter and spring plants which look well with them, and finally showing the very latest varieties - from both sides of the Atlantic. I hope to see you there...

Driving round the M25 (London’s orbital road) yesterday, on the way home from the Royal Horticultural Society’s Garden at Wisley, and for the first time I came to a stop for moment in a traffic jam – just at the right place to shoot a very quick pic of this wonderful graffiti. If you’re interested, it’s on the railway bridge between junctions 16 and 17 and can be seen as you travel clockwise.

For some time it simply read “PEAS”, the tag of a local graffiti artist, and was then augmented.

For many years another favourite of mine was painted in huge letters on a wall near London’s Kew Gardens – “CATS LIKE PLAIN CRISPS” (Note for North American readers: crisps  = potato chips). Sadly, it’s long gone.

Next time, back to plants.

One of the first things I do when I get back to England is check out the acacia that’s growing near my daughter’s house in south London. It’s 12-15ft high and is planted in the grounds of the local school – but this is first year I’ve actually been here at just the right time to actually see it flower. It’s quite a sight.

And it’s a sign of how the climate’s has changed. When I was training at Kew Gardens decades ago, the acacias were either growing in a greenhouse or trained against a sunny wall. Now, only about ten miles from Kew, this one is thriving outside and last winter - one of the coldest for a very long time – does not seem to have hurt it at all.

And it really is quite a spectacle.

Bloom-Again Orchids, by judywhite, has won the Silver Award of Achievement for book writing from the Garden Writers Association in America. The book now goes on for consideration for the Gold Award, announced in September. What's more, the book has already been re-printed and it only came out at the end of November. As the proud husband leading the cheering crowd: Hooray!

Find out more at the  Bloom-Again Orchids website

I’ve been doing some research on daylilies this week. I wanted to check on the flowers of an old British variety ‘Red Precious’. So, naturally, I googled it and took a look at the results.

The two first pages I looked at showed what appeared to be two different plants. Here are the two pages, one from the fine plant and garden photographer John Glover and the second from the expert plantsman John Jearrard. Click on each to see the difference even more clearly.

Of course, I took a look at written descriptions too but that can be frustrating. The fount of all wisdom on daylilies, the American Hemerocallis Society, has no picture and simply says this: “bloom size: 3.5 inches. bloom season: Midseason-Late. Color: brilliant red self.” Not exactly detailed. My own Encyclopedia of Perennials, I have to say, is not exactly crammed with detail on the color, either: “Small, brilliant red, 9cm (31/2in)…”.  ‘Red Precious’ does not feature in the RHS/AHS A-Z Encyclopedia of Garden Plants.

Bob Brown in his Cotswold Garden Flowers online encyclopedia says “Wonderful deep bright red flowers with yellow highlights… Nice old-fashioned narrowish petals…” First mention of those yellow streaks seen in the John Glover picture.

 In Diana Grenfell’s excellent Gardener’s Guide to Growing Daylilies the picture shows the yellow streak but on a mahogany flower, and there’s no printed description.

So, I search in Google Books. A reference comes up to the Proceedings of The Royal Horticultural Society from 1983 but the extract of text it gives is the wrong one. Huh. So I dash downstairs to the dusty corner where all this arcane stuff is stored in rarely consulted volumes and I find that the one volume in my seventy year run of the Proceedings of The Royal Horticultural Society - is the one that’s missing. Off to the RHS website – nothing (more on that aspect another time).

So… It can be challenging, just trying to get a good description of one daylily. Sigh… Time to go and plant that rhododendron we bought yesterday.