Urban jungle: Who needs designers? You do, for a start

SO YOU'VE made the decision to tackle your garden. But before you start ripping out the plants you never really liked and replacing them with trendy must-haves - the scented ones that remind you of that holiday in Tuscany, for instance, or the edible ones the latest TV gardening shows say are essential to any contemporary garden - stop and think.

There are so many things to consider when trying to create the garden of your dreams - the hard landscaping, for one, not to mention the unpredictable nature of the plants themselves, but perhaps the most fundamental thing is whether or not you are the right person to achieve your dream. Enthusiasm is important but unfortunately it isn't always enough. Which brings me to that rapidly expanding species: the garden designer.

If you want a garden with a highly designed look, using a designer is an obvious path to take. But, as with rooms inside a house, there are pros and cons to employing a designer. And as a designer myself, I have to admit that we are not always the answer. But let's run through the pros first.

A good designer will see your garden with fresh eyes - important if you've been looking at the same view for years. He or she will be adept at assessing the parts of your garden that work well and those that don't. Experienced designers will work creatively as well as practically when crafting a space. The practical aspects of garden design are just as important as the creative aspects: an aim has to be achievable, and sustainable through maintenance. Remember this equation: maintenance equals time.

Drawings of the proposed design will show you the long-term masterplan, and help you to visualise what you are getting. Realistic budgeting is crucial, and dealing with landscapers or builders is all part of a designer's job (specifying materials and plants as well as getting estimates). There are new landscaping materials (paving, fencing, pergolas are just a few of them) coming on to the market all the time. Someone who is in the business will be able to suggest appropriate materials to suit the job.

Serious construction needs serious thought. Foundations, thickness of walls, water features: all require specialist knowledge and shouldn't be tackled by amateurs. Putting a wall in the wrong place is a waste of time and money. Seen in reverse, putting a wall in the right place can save a small fortune.

A designer should have an overview of all these things, and be able to tie your space together in a cohesive, proportional, confident and satisfying way. There is also the comforting thought that if it all goes horribly wrong you have someone to scream at and phone up at cruel hours of the night.

Now the cons. Gardens are personal things and, as with interiors, should reflect a person's character. Employing a designer means handing over that personal input, and sometimes can seem like admitting incompetence. There is also the worry of being stuck with something you don't like - a space that seems over-designed, or just not you. If you have all the qualities and the energy necessary to design and carry out the work itself, go for it: express yourself.

But it doesn't end there. There is - as Mr Blair would have it - a third way.

Keen gardeners can work alongside a designer by starting with a consultation. You could have the designer draw up a layout plan specifying materials and some structural planting (trees and larger shrubs), the part most amateurs will find tricky. You can then develop the project yourself, and do your own planting. This can result in a good blend of calculated overview and personal input.

Finding the right designer can be tricky - personal recommendation is the best. Try to view some of your designer's previous work, or ask to see his portfolio. There are many new, fresh-faced graduates coming out of the increasing numbers of garden-design colleges just dying to get their teeth stuck into a job.

Landscape and garden-design degree shows are a good place to look. Most graduates will have good, sound training and will be happy to put in extra hours to gain valuable experience (though experience may seem a worrying thing to lack). As a rough guide, expect to pay about 10 per cent of the cost of the works, thus a pounds 5,000 garden would cost about pounds 500 in design fees - well worth it when you find that your terrace, designed to catch the evening sun in summer, does exactly that.