What are some other options that look very similar and grow as quick as leyland cypress?
I agree with Ian L re the reason that Leylandii cause so many problems in the UK. They are very useful in the right spot and if they are well maintained. They can succumb to several diseases and pests (fact-sheet link below). A single specimen without restricted root space will reach 45ft x 15ft (14m x 4.6m) in 20 years at around 2.5ft per year at it’s peak growth. The reason that staggered planting is advised is that it produces a denser finished coverage than side-by-side. Plant 2ft (60cm) apart for 6ft (1.8m) hedge. For taller hedges or screens the planting distance should be about a quarter of the proposed height (say, around 4.5ft for an 18ft hedge). The Western Red Cedar looks similar but is less vigourous and will re-sprout from old wood when hard pruned which Leylandii will not.
