Landscape dilemma - have the plan from our gardener We have finally decided to invest both time and money in our garden

Go buy plants and trees that you think will look nice rather than ones that someone else likes. Have the fun of going round the nurseries/garden cetres yourself. If it turns out that some of your choices are not quite as you had hoped, then replace them.

Are you saying the designer has just chosen a mix of ornamental grasses and trees and nothing else other than lawn? And which particular trees have they chosen, do you have the names of them, including the varieties? Did you tell the designer what kind of planting you preferred?
I ask because some garden designers have their own strong preferences, but its usual to consult with the client to ascertain what they actually like rather than just selecting planting the designer prefers; it may be you have a bad designer, or you've not been clear about what you want. Can you clarify please?

Otherwise, without knowing the size of your garden and the planting areas within it, its hard to come up with what might suit both your preference and what's practical, so more info on that would be helpful.

This is interesting Odette because I had a similar experience earlier this year. Our designer came up with a brilliant plan which I was thrilled with; then one day he turned up with a planting plan which I hadn't expected. He'd included many plants and trees which he knew we'd had in our previous garden (we've moved house!), and other plants which I didn't particularly like. I explained as tactfully as possible that - to me - the fun part was going shopping and choosing and buying the plants and trees. So he accepted that, and I had a happy time filling the borders with my favourites.

How big is your garden? Ours is about 40' by 60' and I chose Amelanchier, Cercis canadensis 'Forest Pansy', Robinia pseudoacacia and Acer Osakazuki. (I adore flowering cherries, so I put two of those in the front garden: Prunus subhirtella Autumnalis and Prunus 'Chocolate Ice'.) You probably have favourite plants . . . I've put in perennial geraniums, several Phloxes and Penstemons, with pink and purple flowers in one bed; blues, cream and white in another.

thank you. he included an Acer tree, alliums, red robin, sedums and other grasses.
however, I would like to have a nice all season flower bed ... foliage, ferns, flowers and interest all year round. am lost though

the garden is around 50 by 60 feet

Typical 'Chelsea' modern layout... lots of block planting, which is all very well if you like it, but not if you don't.
The tree you mention, depending on which variety of Acer, is fine though, and at least one tree is definitely called for.

If you want plants that look good in winter, that's primarily shrubs, particularly evergreen shrubs, which might be what you mean by 'foliage', though a very few 'grasses' (sedge actually, Carex Evergold for example) look good in winter.. Ferns will nearly all need a shady spot and it doesn't look like you've got one of those...although you say its NW facing, so there must be a shady area somewhere.

Most shrubs flower, although not all are particularly exciting in bloom - what's more important is what they look like the rest of the year rather than the 3 to 4 weeks they're in flower. Otherwise, flowers are provided by herbaceous perennial plants which completely disappear in winter, so you don't want too many of those, a careful selection is called for. I'd go back to whoever did the plan and ask them to change the planting so that its more in tune with what you have in mind, preferably without such extensive blocks of planting, and providing something that should have a flower or three somewhere for 9 months of the year. But first, I'm just wondering if you''re imagining more of a classic garden, perhaps a 'cottage garden' than a contemporary Chelsea flower show design... check out cottage gardens on the internet, have a look at lots of pictures, so you can give the designer a better idea of what you want, and then show some of the images/style you like to him/her.

And if you're not gardeners and don't want to be, ask for low maintenance planting...

It sounds to me that you cannot have given a clear enough spec. to the designer, - or are unclear about what you really want.
You say "I would like to have a nice all season flower bed ... foliage, ferns, flowers and interest all year round." Well yes, that's what we all want but there are limitations as to what is achievable. Certainly you want flowers but foliage gives lots of colour and interest too. I agree with others that you probably want a mixed shrubbery with some perennials. You need to think about variations in height, a good proportion of evergreens, as well as other interest like Autumn colour or berries.
What your designer has offered you looks very modern and smart and would be easy to care for. What you say you want needs a lot of looking after, but you have said you're willing to invest time....