No, because you'd be left with dead trees to remove. Not a pretty sight.

What we've done if a large shrub or small tree needs removing, is to cut it hard back to a stump with secateurs and a pruning saw, and then dig it out. OH has been known to lever the rootball out with a pickaxe!

Is there any chance of digging them out whole and passing them on to a friend or neighbour? What are the trees? It does seem a shame to lose healthy trees. :-(

You could pour pathclear around them till you're blue, but it won't trouble the trees. Cut them down as low as possible, hire a stump grinder and root them out with that -or contact a tree surgeon to do the whole thing, or cut them down yourself and ask a tree surgeon to send someone round with a stump grinder and pay them to do that - they'll remove the debris too.

Type 'kill tree stumps' in the search box top right - this has been covered extensively before, some quite interestig methods, lol.

At five to seven years old they shouldn't be too large, Paul? I would try to dig it out but without cutting it down too far first. If you leave a trunk to grab hold of you can use this as an additional lever. With most trees you don't need to worry about getting all of the roots out as they won't re-grow.
I don't think that anyone who has responded so far will be upset by your question. It is something that we do all the time.

These trees are not in my garden - its for an elderly couple who I sometimes help out with the harder parts of their garden. Sadly as much as I would like to, I cant put in the time that it would take to dig them out and it is too much for them - plus its in a very confined space, and they dont have the cash to pay for a tree surgeon.

One is a silver birch and one looks like a form of cherry tree which is absolutely riddled with blackfly

Oh dear - then you may have to compromise and cut them down as far as you can...yes, I realise that they'll shoot out again.

Hmmm...Maybe brushwood killer would do it if you cut them part-way? Not at all sure. :-((

I'm feeling a bit weary today, Paulr999, so don't want to duplicate here - I have a blog on Tree Stump Treatments which details exactly how to kill off a stump. If you go to my profile page by clicking on my avatar, pick blogs and then select the right one, it's pretty near the bottom of the list. It does mean you'll have to chop the trees down as low as possible first though.

Picked up your very useful blog as suggested Bamboo - thanks for that.

She has her uses, Paul! LOL.