While I was helping a friend pick perennials, she mentioned that though she loved astilbes, they hadn't done well in her garden. “Oh, they like part shade and moist soil,” I advised her. Her response: “Now I know why they did so badly-I planted them in a dry spot in full sun.”
It's not enough to pick plants you like: you need to choose plants that like the growing conditions you can provide.
Sun vs. Shade
Most flowering perennials and roses do best in full sun. If your flower bed doesn't bask in at least six hours a day of full sun, these plants won't deliver as many blooms as you hoped. If they receive only two to three hours of sunlight, they will struggle.
So before heading to the nursery, observe light levels in various parts of your garden at different times of the day-and at different times of the year. This is essential because the amount of sun your yard receives will vary throughout the seasons. Keep in mind that if you don't have a lot of shade, the north side of your house will provide some.
Some nurseries group plants according to sun and shade requirements. Trees and shrubs also have light preferences, so read the plant tags, do some research and ask lots of questions before deciding.
Besides light levels, plants can be picky about soil conditions, so get to know your dirt. (Home soil-testing kits are available at most garden centres.) Many beginner gardeners spend their money on plants, then try to make up for inferior soil by dousing the garden with fertilizer, which creates more problems than it solves. Yes, it does cost more in time and effort to improve your soil, but, in the long run, you and your plants will be glad you did.
Most plants thrive in soil that's moist but well drained-a seeming contradiction that means moisture retentive but not too wet. The ideal garden soil has the consistency of crumbly chocolate cake, is easy to dig and is roughly equal parts sand, silt and clay (the basic mineral components of soil).