Some long flowering perennials....

Penstemon
Helenium
Phlox paniculata
Rudbeckia goldstorm
Echinacea
Kniphofia sp (try the popsicle series)
Agastache
Monarda
Gaillardia
Persicaria
Leucanthemum
Gaura

Also, some of the woody salvias flower for ages. I have cerro potosi, icing sugar and hot lips and they all survive the hardest winters.

You might get away with geranium cuttings, it's a little late but give it a go

Calendula its a brillant flower lasts for ages and re,seeds

every year. no looking after .

Not really a reliable perennial though Eamonn.

Do have a look at the 1773 photos of HPs to be found in the A-Z at the foot of the page. Just click on H and then on Herbaceous Perennials. If anything takes your fancy and you want more information do put your query in another question. I found the goypedia by accident really but it is full of information and I often consult it.

I agree with Badfish, particularly regarding woody Salvias. My Cero Potosi is gorgeous (small shrub) and is still in flower since June; same with all the woody Salvias. Another long-flowering plant is Abelia . . that is also a shrub, but looks after itself.

I think it was Anchorman who did a blog on long-flowering perennials, but that was probably about a year ago! I'll see if I can track it down . . .

Yes . . . see Anchorman's blog, November 2010 - a great list with photos of long-flowering plants.

some of the newer Japanese anemones are good and long in flower but with out the thuggish reputation of some of the older varieties.

Try geranium sangunium. Some varieties flower more freely and for longer than others but I've a light pink one that is stil flowering now. I'd second Penstemon as well, non stop all summer and still at it. Don't forget plants grown mostly for their pretty leaves as well.

Here's a link to my blog here on easy care long flowering season plants

http://www.growsonyou.com/anchorman/blog/12681-plants-with-a-very-long-flowering-season

The very best of them all is probably Erysimum 'Bowles Mauve' which can often be seen still in flower from year to year. I grow it with Malva 'moschata alba' (white mallow) . . . a pretty combination. Good luck Eileen!

Yes I have a "Bowles Mauve" that flowered continually for 10 months,stopped for a week and flowered again. It is effectively a perpetual flowerer even in hard winters if flowering stems are removed after flowering.

It grows easily from cuttings and cuttings taken one year make a good sized plant well over 30 cm in circumference the following year .

I would also highly recommend rudbeckia which flowers from early July to as late as December in a mild winter and penstemmons do much the same