Many thanks everyone! That's hugely helpful. I've decided to keep everything except the Laburnum. That one will come out in Autumn so I can poison the roots with SBK at the same time. Hopefully that's the right time to remove it?
I have a few more now that I would like help identifying, before I decide whether to keep or cull...
1. This tree was one I was about to remove, but suddenly it burst into flower this week and looks beautiful. It has an old flakey bark. Any idea what it is?
2. The next one is a couple of tall-ish trees that look very similar to my box hedge. But could it be?
3. Next to that is another tree that grows very quickly. I don't really like this one much, so was going to remove it unless someone can tell me it is something special worth keeping?
4. And now a small weed that keeps emerging throughout my flower beds. It doesn't grow very tall, and perhaps isn't even a weed at all?
5. And finally this is a weed that grows at a ridiculously fast pace. At least it is easily removed. The stems are weak, but as soon as I remove it it is back again under and through my front hedge. Any idea what this one is?
If you can name any of the above I'd be really happy.
4 Euphorbia cypariassis ( I might have mis-spelt that, but close) not an official weed, but.......
5 white briony, Bryonia dioica, a native, big root like a parsnip, weed
Thanks so much nutcutlet! Great to know what they are?
Any views on whether to keep them?
The Philadelphus looks beautiful so can stay.
The privet has turned into a tree and looks a mess so I am thinking to get rid of.
The hazel is a bit too large so I was thinking to cut down and replace with something else. But maybe I shouldn't? Is Hazel a "desirable" tree?
I agree, privet has not got a lot of charm and is the first I'd get rid of.
Hazel has a useful characteristic: for centuries it has been "coppiced" to create hedges and provide sticks. If you cut it right back, it will grow back with a number of new, thinner stems. It is also used in traditional hedge-laying because of this. Yours may already have had this done before, judging from the photo. Whether you want it to carry on as a shrubby, hedgy sort of plant is up to you and may depend on the space available. You may get nuts from it in the autumn (but squirrels may get there first) and in the spring it has catkins.
I hate privet, and the scent (stink) of its flowers.
Hazel, it depends on the size of your garden. allowed to grow up for catkins and nuts it's great if you have room.
White briony is a swamp everything climber with poisonous berries and a root like a parsnip. Fine in a wild patch like mine but not for polite company
The euphorbia is somewhat invasive, again, fine if you have room
Philadelphus - great - prune straight after flowering to however high you want.
Hazel - from my experience get rid of it - my neighbours have a huge one right next to the joint fence its towering over everything, and I remove at least 30 little ones from all over my garden every year.
Privet is bland and smelly but it depends on you.
The euphorbia spreads around but is not hard to pull up so its a personal taste thing.
Remember its YOUR garden and totally depends on what You want. Walk around parks and garden see what you like and if it fits get it.
Just to add about the philadelphus, after flowering you could take out a few stems 6inches from the ground, helps to promotes fresh growth from the bottom. I think it flowers on older stems, the flower next year will be on the growth this year, somebody else I am sure confirm or not. Also has a lovely scent
I agree with Cathy43 - take one third of the stems out at the base this year, another third the next year and the last third the following year - you'll have a totally rejuvenated shrub - give it some Fish Blood and Bone and water it in well - that'll perk it up.
Thanks for the great advice on the philadelphus. It seems a previous owner (not the last one - she left the garden to turn into weed-covered jungle) did look after the philadelphus and did this, because the base has many old stumps.
So, for cutting back 1/3 of the stems I can do that straight after flowering? I don't need to wait until the leaves have died back?