what plants can i use in shady conditions

welcome from me gizzy
By heavy do you mean clay soil?
Vincas
Skimmia (acid soil)
Viburnam davidii
Hypericum calcycinum
Mahonias
Junipers
Corylus - Hazel (good wind tolerance))
but how narrow do you mean some of these will be too wide possibly?
We are like london buses more members will be along soon with other ideas good luck

Japanese Anemone, Geranium, foxglove, Hydrangea, Tiarrella, Hosta.Cotoneaster.

Vinca minor varigata.. Is silver varigated and keeps bright throughout the year, would mnake good undercarpet.

Primulas will do well in clay soil and give lots of spring colour too. Pulmonaria, bergenias. If plenty of oragnic matter is worked into the soil, hydrangeas should grow well (although they may now flower as well as in some sun). Campanula trachelium, the nettle-leaved bellflower, is also growing well for me in dry shade on a clay soil - this flowers in July so is useful for some summer colour

Welcome from me too Gizzy :)
How about euonymous, ivy, hardy geraniums, low growing spring bulbs, and alchemilla...

Well you did ask Gizzy, hope you've plenty of room (smile)

Hi Gizzy,
I have a similar problem. In addition to any of the above, if you wanted annuals for summer colour I find bizzie lizzies or fibrous rooted begonias or nasturtiums all thrive in shade. Fuchsias seem happy enough too.

How tall would you like them to reach and, how wide is the strip ?

If you're after plants under 12" how about Heucheras ? No-one's mentioned them and they would add loads of foliage colour to a shadey area.

If you're after taller plants i agree with Crazydi.
Euonymus would be good there - they've got variegated foliage and can reach 5'.

welcome gizzy. i have a lot of shade . have a look on my plant list on my profile for suggestions.