When you start gardening with perennials, it's easy to think that all you have to do is get your plants into the ground, and with the exception of weeding, watering and cutting back, your garden will be done.

But here's what really happens: in the first year your new plants are underwhelming the clumps small, the flowers sparse. By the second year, your perennials have grown fuller and have more flowers, but in the third season watch out your plants look like they're on steroids, and you look like an accomplished gardener.

After that, many plants get bigger each season, while the odd one confounds you by doing a disappearing act. Responding to the inevitable change is your challenge as a flower gardener.

Veteran gardeners say that no flower garden is ever truly finished. When I was starting out about 15 years ago, my husband used to joke that my plants should have been on wheels because I moved them so much.

Perennial plants are the backbone of the flower garden because they're the plants with staying power. Their leaves die back as winter approaches, but with luck, the following spring, they come back. Some plants are short-lived, but old favorites like daylilies, hostas and peonies can last for decades.

The right perennials for your garden

When you're planning your flower garden, there are many choices to make some purely aesthetic, such as match-making with winning perennial combinations, and some purely horticultural - what grows best in your conditons.

The more closely you base your decisions on meeting the needs of your plants (in terms of light requirements, soil, moisture levels and so on) and on which plants look good together, the more likely you are to be successful with your perennial gardening.