Hi, I think a border of Erysimum bowles mauve would look fantastic, just leave a few gaps for your summer bedding, they will flower for 12 months of the year, literally flowering themselves to death, just take some cuttings every year to replace any that give up the ghost, Derek.

Derek, will they do that up in north Yorkshire? They do here, down south, but not sure if they would somewhere a lot colder.

I'd ask if the bed is in sun or not...

Hi Bamboo, I think they would be ok, it's pretty cold where I am on the pennines, and they do for me, Derek.

Thanks . Forgot to say that the border will be in full sun, neutral heavy soil. I have a Bowles mauve in the back garden . Is it too late for cuttings?

I wish people wouldn't talk in this new fangled miters and cintermiters, I can't visualise these sizes. I'm from the old school and still work in LSD. :o)

I know what you mean Myron - I now use metres rather than feet and inches, but for visualisation, its much easier with imperial, I know what 6 feet looks like in my head...

Yes, Barbarak, its too late for cuttings now. A photo would be helpful here - you seem to be saying there's a wall behind this raised, narrow bed which is 30 cm high, is that right? But that the bed itself is raised in some way?

dwarf hebe are good small silvery green leaves with white flowers are good. Then you could do all bedding , Primula, violets/violas dwarf wallflowers, Brompton stocks. Hechera, is a possibility too.

You've hit the nail on the head there Bamboo (a 6 inch one). Feet and inches are easier to visualise for me too. However, when I'm making something and need to take measurements I use metric because it's easier to add up. For example, 628mm + 326mm is easier to add together than say 1" 2 1/2' + 2" 6 3/8'.

Years ago when they changed the law and shops had to sell things in metric instead of imperial, my mother went into the greengrocers and asked for 5lbs of potatoes. The greengrocer said, "Sorry madam EU rules, as from today it's kilograms". So my mother said, "Oh, ok, then I'll have 5lbs of kilograms then. God bless her.

Okay enough already about metric. 30cm=12inches , the border is about 43 feet (14 yards approx) . I 'll take photo tomorrow and post.
I do like the idea of Hebes, are the dwarf ones more frost resistant as I lost larger ones in the winter of 2010/11

The one I have Hebe pinguifolia 'Pagei' has survived in my east Yorkshire garden for 12 yrs and it can be kept as small as you like with pruning. It has white flowers in the spring/summer. in that horrid double winter we regularly got down to -15 over night. I lost lots of other hebes but not this one. Take cuttings well too.

Hi Barbarak, I've recently had a new path laid which gave me a narrow border about 2ft wide x15ft.
So far I've planted a selection of dwarf Hebe.."Wild Romance", "Pagei", "Green Globe" and "Caledonia", along with some "Dianthus deltoides" and "Ajuga"..all evergreens.
I'm also thinking about some Sedum. All good for some Winter interest..I hope!

Thanks for suggestions

It doesn't look 30cm wide on the photo! Two thoughts - are you going to fill the space with soil? And if you are have you left any drainage holes at the foot of the inner wall?

I believe Moongrower and Bulbaholic have lots of those double walls in their garden - might be a good idea to pm them and ask what they would advise if they didn't see this question..

You need to leave a vertical line of mortar out of every other 10th brick or so in a row near the bottom for drainage.

The walls are new. It has weep holes and the border will be filled next week with the topsoil that was removed. The gap between the wall is exactly 30cm. We plan to fill the space with rubble up to the level of the weep holes and then topsoil so the border will have adequate drainage.

Dianthus are a good idea - flowers in summer and evergreen the rest of the year, and they would make a nice background for your summer bedding. Some ground cover roses might be nice and less bother than bedding plants?

If the wall gets plenty of sun, I'd use Helianthemums such as 'Ben More', Sisyrichinchium graminoides (blue flowered grass) Iberis sempervirens, Aubretia, Arabis procurrens variegata, and other Arabis varieties, Oophiopogon nigrescens, Silene uniflora 'Druitt's variegated' and other Silene varieties for later colour. All are evergreen, though the Silene druitts variegated sometimes disappears below ground in a cold winter. If its not too sunny, Heuchera varieties are worth considering, with their wide range of coloured leaves.

Thanks bamboo. Just starting to back fill the border now , have been advised to let the soil settle a bit first before planting so will keep your ideas until spring.