L d pendula is easily staked to whatever height you wish ... and will go back down from there ... [L kampheri is a look alike and usually confused in the market... 6 of this.. half dozen of the other .. either will work]

but it is deciduous ... which i think is cool ...

if you dont go with a true pendula.. no conifer ever really stops growing in height ... so all others will .. eventually overgrow your wishes ....

you will get much better suggestions.. if you offer us a pic of the spot ...

the difference between an old name.. and a newer name.. is usually 20 dollars or so ... lol .... 15 pounds for you i suppose .. lol ...

the bruns has vast potential in height... and do understand.. that MOST height estimates are at 10 years... and it will easily be twice as tall at 20 ... except for the true pendulas that are trained to height as noted ...

ken

That's an odd height request... 20-30ft? In what period of time?

If you get something that will reach that height in the next 10-15ft years, that will a tree with a very fast growth rate and it will continue to rocket up to 40, 50, 60ft in the years that follow. On the other hand, an intermediate, will eventually hit 20-30ft, but it might take 20+ years to do so. What's the sun situation, you will need full sun to achieve the best gold color with most conifers.

The easy choice for me would be Picea abies 'Gold Drift' or maybe Metasequoia glyptostroboides 'Miss Grace', but they both would take decades to achieve 6-9m.

Ken_adrian:
I will try to post a picture of the spot for you tomorrow. The fact that L d pendula is deciduous was one of the reasons that attracted me to it in the first place. I wasn't clearly that with staking I could keep growing (even if it will take a long time).

SC77:
With this height I was thinking on a 15-25 yr horizon; my point was I didn't want a dwarf or something that will reach 50ft in 20yrs.

As you can probably tell I am not an expert in this area!!

Sun - this spot will get sun in the morning and then dappled sunlight/shade throughout the day.

Which would be faster growing: Ld pendula or Picea abies 'gold drift'?

Buy the weeping Japanese larch, install a pole to train it up and try that. Photos from Britain show it as Larix decidua 'Pendula' so there is the same mixup in commerce there as here.

Or visit some outlets with good assortments of conifers to see if there is something else that looks just right.

Your in the UK, so presumably you fear that your tree will act like the dreaded Leyland Cypress! Really, there arn't too many trees that will hit 50ft in 20, other than Leylandii in an ideal location like the UK.

20-30ft in 15-25 years would allow you to plant something with a pretty rapid growth rate. Maybe even a weeping form of Sequoiadendron giganteum would work:

Sequoiadendron giganteum 'Barabits Requiem'
Sequoiadendron giganteum ' Pendulum '