Posted: 12/06/2012 at 16:57
If you want to go into design then you will have to go back to college and take design courses.Build up experience and a portfolio of what you have created etc. This will probably working for friends and family initially (probably for nothing) to build up your reputation and skills. Working for a landscaping company as a 'labourer' will give you experience in 'making the earth move'.
I too completed my RHS Level 2 - I maintain my 'day' job but garden for my local school for fun/volunteer status. Sotongeoff is right I'm afraid. In this climate of recession, there is little money for niceties even for proven pros. I wouldn't give up your day job - but try to get more qualifications/experience and do more research as to where you could fit it in the horticultural world. Maybe PA for RHS....a gardening or nature based organisation may satisfy both your sets of skills.
You unfortunately will not make a fortune in gardening unless you are very talented - Chris Beardshaw; Dermot Gavin; Alan Titchmarsh; Carol Klein and they have all diversified from being just 'a gardener' or 'designer' or 'nurseryman/woman' to TV presenter, author etc.