Evergreen clematis are invaluable garden climbers and at this time of year Clematis armandii, in its various pink- and white-flowered forms is really spectacular.

I’ve been looking at the plant sales areas at garden centres around Britain over the last two or three weeks and one plant I especially noticed was a new form of this excellent plant – ‘Enham Star’. Discovered in the horticulture division of Enham, a national disability charity, the flowers are white with a slight pink blush and ‘Enham Star’ is said to be unusually prolific – and it certainly looks that way from the large plants I saw on sale. Look out for it in the new RHS PlantFinder, out next month.

Oddly, though, go to the Enham website and there’s no mention of the clematis at all.

This is just to say that you can read my article on Clematis cirrhosa in today's Daily Telegraph here.

You can read last week's piece on hellebores here

And my piece for them on winter arums here

And my piece for them on bergenias here

And my piece on winter flowering pansies here.

And another piece, on growing your own mistletoe, here.

The Daily Telegraph is one of Britain's best-selling daily newspapers and winners of the 2007 award for the Gardening Newspaper of the Year.

I think this is a first! Plants of a recently introduced sweet pea in the old-fashioned style are now available - on both sides of the Atlantic. In North America in particular it can be hard to find sweet peas available as plants by mail order so this is a welcome development.

'Fire and Ice' is a recent introduction, an heirloom Grandiflora type, it's a red and white bicolour with a powerful fragrance. The wings feature an intriguing colour change: they start white with a blue edge and the blue colour slowly expands. It's great to see plants available by mail order on both sides of the Atlantic.

It turned up by chance as a mutation in a row of plants of a maroon and violet bicolour on Mark Rowland's trials at Owl's Acre Sweet Peas in Lincolnshire in eastern England. He selected it out, trialled it to be sure it was stable and introduced it on a limited scale in 2005. It made its debut at the Royal Horticultural Society's Wisley Flower Show where the picture was taken.

Plants are now available in North America from Heronswood.

Plants are now available in Britain from Simply Sweet Peas.

‘Goldheart’ ivy is one of the most popular of ivies on both sides of the Atlantic. Its brilliant buttery splash in the center of each dark leaf certainly livens up a sunless wall in winter and its pink yonug stems add extra appeal. But recently I’ve been noticing a big problem with ‘Goldheart’: it reverts, losing its yellow coloring.

The first picture shows a huge plant in Aldgate in East London. Click on it for its enlargement and you’ll see a few sparks of yellow but it’s mostly green. The problem with all that green – apart from the fact that it’s dull – is that the plant grows so much more strongly that it both gets out of hand and swamps the increasingly few colourful shoots.

In the second picture, in Northamptonshire, it’s also reverting and is again getting too large for its space. While on a fence round the corner you can see that even relatively small plants about 5ft/1.5m high can revert and the green shoots start to dominate.

The other thing to keep in mind about this plant is that it seems clear that almost everyone uses the wrong name. The correct name is most probably not ‘Goldheart’, but is most likely to be ‘Oro di Bogliasco’ (it was discovered near the Italian town of Bogliasco) or perhaps even ‘Jubiläum Goldherz’.

‘Tricolor’, also consistently with some pink coloring, and ‘Goldchild’, an RHS Award of Garden Merit plant, are perhaps better gold and green alternatives.

Although I thought Physocarpus Coppertina was the most promising of last year’s trial shrubs and vines, as I discussed in yesterday's post, the first year of some other newcomers was also very encouraging.

The pretty silvered Schizophragma hydrangeoides 'Moonlight’ is planted to climb an oak tree, just as these self-clinging plants do in the wild; it grew away well last year, sailed through the winter, and is now setting off further up the tree, where it’s areial roots grip without much help, and across the nearby soil. The foliage turns an attractive yellow in the fall. Two true climbing hydrangeas,ne forms of Hydrangea anomala subsp. petiolaris made a much slower start, and ‘Firefly’ which is supposed to be variegated seems to have discouragingly plain green leaves; perhaps the color will develop later.

Most mail order seed companies, on both sides of the Atlantic, sell sweet pea seeds but there are relatively few which offer a really good range. And only one sells a good range of sweet pea plants. As spring approaches (in some places at least) I’ve had a couple of emails recently asking for good sources of sweet pea seeds - so here goes.

North America
There are three excellent American suppliers who specialize exclusively in sweet pea seeds.
Enchanting Sweet Peas 244 Florence Avenue, Sebastopol, CA 95472.
Fragrant Garden Nursery P.O. Box 4246, Brookings, OR 97415.
Sweet Pea Gardens 614 Surry Road, Surry, ME 04684

In addition, Renee's Garden (Online only), has an fine range along with many other heirloom flowers.

Britain
There are more sweet pea specialists in Britain and Simply Sweet Peas (online only) specialize in sweet pea plants, which is ideal for many gardeners. In addition, I would single out these seed specialists although none in my comprehensive list will disappoint.

Matthewman's Sweet Peas 14 Chariot Way, Thorpe Audlin, Pontefract, West Yorkshire, WF8 3EZ
Cooltonagh Irish Sweet Peas (Online only)
Owls Acre Sweet Peas Owl's Acre, Kellett Gate, Low Fulney, Spalding, Lincolnshire, PE12 6EJ.
Roger Parsons Sweet Peas Primrose Cottage, Clayton Lane, Bracklesham Bay, Chichester, PO20 8JQ

In addition, these two companies list an exceptional range along with a very wide range of other seeds.

Kings Seeds Monks Farm, Kelvedon, Colchester, Essex, CO5 9PG
Unwins Seeds Alconbury Hill, Huntingdon, Cambs, PE28 4HY.

Please click here for my latest comprehensive list of suppliers on both sides of the Atlantic.

And don’t forget my own book on sweet peas The Sweet Pea Book – just click on the jacket (below left) to find out more.

Good luck with your sweet peas this season.