At the nursery, temptation lurks on every shelf and around every corner. I can be drawn in by the shape of a plant's foliage, the color of its bloom or some altogether inexplicable reason. Over time I've learned to build up my resistance and approach the purchase of a plant with a somewhat cooler head. It requires taking a breath, pulling out that little tag that's stuck in the pot and reading it. It is the information on the tag that will tell you whether you and that plant will live in happy harmony when you get it home or if it will soon perish, leaving you sad, dejected and wondering what went wrong.
When reading the tag, the first thing I look at is the exposure requirement. There are sections of my deck that are full sun (six or more hours of direct sunlight) and other sections that are part sun/part shade (around three or four hours of sun). So if the plant I am so enamored with requires full shade (less than 3 hours of light), I just need to walk on by. I advise you to do the same.
Next, if I'm looking at a plant that produces flowers, I consider bloom period. I love lilacs and peonies as much as anyone but I never grow them because their bloom time, while spectacular, is just entirely too short. My ideal is a bloom period of spring until fall (May to October) but I'll settle for June to August if I have to.
I also am interested in whether or not I'm going to have to add a lot of esoteric ingredients to the soil, or use some special sort fertilizer or other high-maintenance sort of thing. I just can't appreciate an overly fussy plant, no matter how pretty it is. The use of ordinary potting mix and the occasional application of a water soluble fertilizer is about all I'm willing to do.
Finally, I determine what my objective is for the plant. If it's a perennial, do I really want to try and have it return every year? If so, I check the Hardiness Zone. I live in a zone 7 and my rule of thumb for perennials that I want to make a repeat appearance is to make sure they are a zone 5. That's still no guarantee, but it's worked pretty well for me so far. Of course, I don't plant them in itty bitty pots either because there needs to be enough soil and space to protect it from exposure to the winter elements.
Remember, the folks at the nurseries are there for a reason. Where I shop, they are nothing less than brilliant. You may not encounter that level of expertise at a big box store but that's okay. If you find a plant you like that has a name label but lacks the details, go inside the store and find the book or magazine section and see if you can look up the plant profile by name. Otherwise, my advice would be to wait until you can get more information before you plunk down your money. In the end, you'll be happy you did.
Bookshelf: Container Gardening Books