If you go to the garden centers in the spring you can frequently see the clematis in bloom which is wonderful as you can then pick exactly the one(s) that appeal to you. Look for a vine that looks healthy and unblemished. Note how many stalks are coming up from the soil. The more the better. On the day of planting water your clematis with a transplant solution of water and 10-52-10 fertilizer (mixed according to package directions) and let it sit and nourish itself while you dig it's new home. Or get someone else to dig a rather deep hole, perhaps 16 inches deep if you can manage it by 14 -18 inches wide. Dig, dig, dig. Done. After you have dug your hole place a shovelful of compost or aged manure into the bottom (not fresh manure). You can add a small handful of bone meal or blood meal but be aware of your soil type first. Calgary soil tends to be very alkaline. Blood meal will make the soil more acidic & bone meal will make the soil more alkaline. Add the appropriate meal if you wish and mix it with the compost. Place the clematis in the bottom of the hole so that the top of the soil where the clematis meets the soil in the pot is about 6 - 8 inches below the surface of the ground. Place something around the newly planted vine to keep the soil back - perhaps cut out the bottom of a large perennial pot and place it over the clematis. Fill the soil in around the pot right up to the surrounding ground. Inside the pot add soil only until the surface of the soil around the plant is 6 - 8 inches from the top of ground. The reason for this is that you want the stems to harden off throughout the summer then in the fall (or even the following spring) you will remove the pot and fill the soil in around the plant right up to the height of the surrounding soil. If your clematis is approximately 1 foot or more high then trim it back to about 6 - 8 " high. It is hard do this but you will be happy later that you did. It will cause the plant to produce more shoots and therefore become a fuller plant sooner. If you cannot do it yourself then give someone else the shears and close your eyes and let them get on with the deed. You will have a far fuller plant just like when you pinch back tomatoe plants or petunias.
The first clematis on the left is a Helsingborg Clematis, then a Lemon Bell Clematis then the only large flowered clematis I own. Unfortunately I do not know what it is as the label was missing but it was in bloom and was so lovely I bought it against my better judgement. Hopefully I will be able to figure out which one it is this summer... in front of the clematis is a small Meadow Rue (Thalictrium).