Tree

elsien

There are less prickly varieties of holly which are easier to deal with. Would need pruning  though to keep it to the right size and shape. 

Silvertabby

-taff said:

I'd have a look for a tree trained ceanothus too, lovely blue flowers in the summer and evergreen.

I would also think about whether whatever you grow is going to hang over the fence. If you own the bits outside the fence  fine, but if your neighbours do, expect them to cut it level with the fence if it overhangs.

Ceanothus are lovely, but not very long lived, especially in poorly drained soil.

Lorian

Hornbeam. copper beach.  you need to keep on top of trimming them but both manageable, both retain leaves (mostly) in the winter

35har1old

FreeBear said:

Don't plant a conifer or a laurel - Both are fast growing, and whilst conifers pruned at ground level don't return, laurels will throw up suckers until you dig out the roots.

Holly would do the job, even better if you can get a female. Tolerates extreme pruning, even at ground level. But dead leaves & prunings are prickly to deal with.

Eucalyptus is also fast growing, and some can be copiced/pollarded (Snow gum springs to mind). But being shallow rooted, they are prone to being felled in high winds if allowed to get too big.

Myrtle would be a good choice in my opinion - Not very fast growing and unlikely to get more than 4m high. Dark green leaves all year round (you can get a variegated variety, but it isn't that hardy in my experience). Leaves & flowers give off a pleasant scent, and the berries can be eaten.

I have seen Myrtle reaching 10M

FreeBear

fatbelly said: Callistemon Bottle Brush

Callistemon, whilst a very attractive tree, needs a mild climate. A decent frost is likely to kill it - RHS reckons -5°C to be the limit.

sheramber

Visit a local nursery for advice on what  grows best in your area. 

If you want to buy a grown  tree / shrub it will be expensive and require a lot of muscle power  to plant it.

twopenny

Good point about the spread of the canopy.

If it's 4mts tall it's going to be 4mtrs wide - unless you choose a variety that grows upwards.

I've got a little Prunus which has lovely purple leaves, blossom in February and the particular type is columnular so doesn't spread so wide and the roots similar.

Putting a tree in the paving of that height the roots are likely to lift the slabs eventually.

Katiehound

no one has mentioned Euonymus- there are some pretty variegated varieties such as Emerald gaiety or Silver Queen ( and many more) which are all evergreen.
 Interestingly if these are planted near a fence they will grow tall- if planted in the centre of a bed they form a mound. They are hardy too. I had one that grew to the height of the bathroom roof as it got behind clematis netting.

Dustyevsky

There are a few weird suggestions here, especially the plants which won't reach the height required, or grow well if the soil is alkaline. There's a good photo to work from, but I'd like to know the aspect, and what lies behind the photographer in terms of other garden space.

It is assumed the OP wants privacy, but it's a big ask to find a well-behaved, low maintenance tree or shrub which will do the job quite quickly, be effective all year, yet not affect the neighbours' garden. Maybe a couple of camellias would do it, though not on alkaline soil.  A pittosporum is another possibility. It's reasonably quick growing in the bog-standard variety, easily-shaped, and not prickly.

However, this space may not see much action in winter time, in which case, deciduous plants may do the job required just as well.

We don't know the height of the fence or who owns it, but as a boundary, 2m is the maximum allowed. Rather than plonk a tree close to it, I'd  step back about 0.6m and run a pergola through there, possibly with some shaped trellis, and grow climbers, including vines. They're easily maintained in winter and helpfully clothe themselves when the season's right for barbecues and sitting out. If that corner's sunny, a triangular covered section might be a good place to put a shady seat for the summer.

There's often an answer to privacy in smallish gardens that doesn't involve pushing big plants up against the boundary, but that's what most Brits do! Then they get stroppy with one another when the inevitable incursions and overhangs happen, as evidenced by posts on here.

I know my suggestion's maybe not helpful to the OP, who's just had rather nice paving laid, but lots of people read this section of the site. It may help someone taking-on a new, overlooked garden, to think out of the box. If you think it's a rubbish idea, that's fine too.

(Edited for terrible first-thing-in the-morning wording.)

KittenChops

Maybe one of these?  Or similar
https://www.rhs.org.uk/plants/4666/cotoneaster-salicifolius/details
We have one (moved here just over 2 years ago, previous owners did nothing with the garden so it was likely here 10+ years ago)
Evergreen, berries for the birds
We've raised the canopy on ours (pruned off lower branches) so can plant underneath it