Hi Joe,
As well as my hypnotherapy/NLP businesses I have been a Garden designer and Landscaper here in the UK for 20 years.
One mistake that is repeated worldwide and I constantly have to tell my customers about is this.
If you are growing a hedge or even a shrub that you require to make into a solid screen then PLEASE TRIM IT REGULARLY. Depending on the type of shrub, a good GENERAL rule is: Prune immediately after flowering , but, PLEASE BE PREPARED TO CUT BACK THE GROWTH.
I attend a clients' gardens and am then asked to TRIM the hedges:
''but don't take any off of the top, I want to grow it another three feet to hide my neighbour's garage''.
WRONG
If you wish to grow a hege that performs a screening function then you need to cut the top growth down every so often.
Remember, each twig that you trim will probably make three, next year you trim those and
hey presto: nine shoots but a little taller.
RESULT: A solid well-shaped hedge not a collapsing mess with a very sparse look.
Roger