Plant ideas needed for an established back garden that has gaps in the borders

[BrilliantlyStupid]

I have a medium sized rectangular shaped back garden. The previous owners were keen gardeners and planted the following plants which are all well established (most are above fence height):
-several Cordylines
-a gorgeous Acer tree
-Ivy and Hedera Helix that partially cover the fences
-a few pink/dark pink peonies
-a few tall Virburnums with dainty white flowers
-what I think is a bush shaped Virburnum with big white ball flowers in summer
-a grape vine covering a trellis with arch that divides the garden into two halves
I have many gaps in the garden between these plants and I need some help deciding what to plant between them. I feel that the garden looks very green but lacks colour! I am keen to continue with our lovely garden but I am new to gardening so need ideas of what plants would go with what I already have.
Standing with my back to the house I face east as I look out over the garden. It is a long and fairly wide garden that gets the sun most of the day, except on the patio by the back door.
Oh, I hate the colour yellow and love pink, purple, lilac, blue, red!

What about a large Cranesbill geranium such as Johnsons blue or Anne Foulkard, which is magenta with a black centre.
Both these are trouble free and will bulk up to fill the gaps. Also the thane a fairly long flowering season.

Thank you, both are really pretty - I have added them to my list! Would you plant them singularly or a few together to get a decent size spread?

Depends on the plants you can buy. Both do spread, but if the garden centre has 1ltr pots then getting a couple to fill the gap would be good. Once established the are easily divided, so anything that outgrows its space can be split, put elsewhere, or potted up and given to friends.

That's good to know, thank you!

It sounds as though you have quite a few shrubs, and some good structure there, so I would maybe focus on some hardy perennials. It's hard to know what to suggest because, to be honest, I could go on for pages, because there's a ton of stuff that will grow in your conditions! Have a look at a site like Claire Austin's hardy perennials and make a shopping list!

shovetheholly, that website looks fab, particularly the articles. I'm going to make a cup of tea and have a good browse. I may follow up with my list of plants I like to see if there are any pitfalls with them. Thank you!

Do! It would be lovely to see what you order! I had to restrain myself from suggesting things because there is SO much you can grow that the list would have been ridiculous!

So far I really like the look of Erysimum 'Bowles's Mauve' and I definitely want to get a Cotinus coggygria 'Royal Purple' (smoke bush) as the colour is stunning!

Cotinus is a large shrub, even if you coppice it, not really a filler plant.

My best filler plants are

gaura lindheimi (sp?) white or pink
bowles mauve erysimum
penstemons
heucheras
alchemilla for front of border
geranium johnson's blue medium height
geums front of border
forget me nots look lovely as this time of year
and day lilies might work, if you can find the right colour
some grasses too, the low ones like the carexes (white and green striped or the bronzes ones) There is a grass called Luzula nivea something or other that copes with quite dry under shrub conditions, looks lovely massed in fives, especially in spring. Pulmonarias always get eaten by slugs in my garden as do bergenias, but they are usually recommended for mixed borders.
Cosmos is a great filler, you can usually get it in garden centres in little pots, it bulks out amazingly.

avoid things which need too much rich fertile soil as the shrubs might be taking the light/water - my red hot pokers did very badly in amongst shrubs, and I found the same is true of rudbeckias, dahlias

I would always try and plant in threes rather than dotted around if you have lots of garden! So three small plants in a triangle or rectangle rather than spaced evenly throughout. CROCUS website has some good examples of plans if you look on inspiration.

Iris sibirica can also make a nice clump (proper irises can be over too soon and then a bit ugly)
Phygelius and Cistus are lovely low shrubby fillers, you can get them in dark pinks (phygelius) and whites (cistus)

try not to put too many different things in though, keep the repetition going, much more restful, imagine big clumps of things, as nature's way of growing plants

knitting, that is incredibly useful info re planting as I do have lots of garden, thank you! Its also very good to know what plants to put at the front of the border (as I wouldn't have a clue!).

Don't forget for later in the year
I will try not to get carried away either, like shove , but I do love asters for later in the year , and Japanese anemones too

Erysimum 'bowles mauve' is a corker. It flowers continuously, all year round in my garden. Amazing plant. If you're on a sunny site, salvias can be brilliant.

book speaks wise words - try to find something that will be in flower every month of the year! Otherwise it's tempting to go to the garden centre and fill your trolley with things that look lovely now, which will leave you with big blanks towards the summer and autumn.

(It is confusing at the start, and a LOT of work - but doing the research now will mean the end result is so much better!)

If it's the color of the cotinus you like then heucheras come in that lovely dark purple too, they are good for the front if a border and easy to grow.

Sorry placemarking!!

Dicentra spectabilis (it has a new name now I think not beginning with D, something like Lamprosos) / Bleeding Heart, Lady's Locket looks very good in spring, late spring, and makes absolutely ginormous clumps very quickly - in white or pink. You can buy it from B & Q in bare root form (in the dahlia/perennial bare root section in cardboard boxes), which is even cheaper although it might take a bit longer to clump up.

Great suggestion - it's now supposed to be Lamprocapnos spectabilis, but I keep calling it Dicentra too. For some reason I keep getting all the syllables of Lamprocapnos in the wrong order. Also, in my head it sounds like a Lamprocapnos is a fish.

I really like the white one. I can take or leave the pink.