This time of year, it’s easy to be whipped into a gardening frenzy! Mornings are still somewhat cool, and the Dog Days of summer haven’t quite hit yet. So when Saturday mornings roll around, you’ve probably watched a garden show or two and are now inspired to hit the nursery to snap up some more plants. But wait a minute—remember that last time you went? You came home with plants that didn’t work and you had no idea where to put them. Well, no worries, I’m here to help you avoid that scenario.

Come prepared. Take some notes about the part of the garden you want to add some plants to—is it sunny or shady? Rocky or deep soil? Any drainage issues? How about critters—do you have deer or dogs? How much time are you willing to spend every week on maintenance? What other plants do you have in this area? The garden below is mostly shady and lacks height, structure and definition—bring notes like these with you to the nursery.

Choose wisely. Once you’ve decided that you want pink petunias or purple fountain grass, begin choosing individual plants. Choose plants that are healthy—with no obvious pests or diseases. Pass up plants that have a lot of dead foliage, holes in the leaves, or spots on foliage, or that are either too small or too large for their pots. Plants that seem too small for their pots might not be well rooted, while too-large plants can be pot-bound and difficult to transplant.

Think like a designer. With few exceptions, plan to purchase a number of each plant, and plant them in odd numbers (3, 5, or 7). If you like alliums, for example, buy 9 one-gallon containers and plant them in groups of three in different parts of your garden, as in the garden below. The only time you should purchase one of a certain plant is if it’s a focal point plant, like an agave or a specimen palm.

Do your homework and, when in doubt, get a trusted nursery worker to help you out. They are there for a reason, and they want you to have a great garden. And with a little preparation and some thoughtful choices, you will!