Clematis is the king of the climbing flowers plants, but it doesn't always do so well in the shade. Normally, clematis requires 4-6 hours of direct light, to bloom well. These days, a person is discovering a new hybrid every day, which is rewriting all of the old rules about plants and horticulture. There are a lot species now that withstand some indirect light and even grow on a north facing wall.

An important thing to remember when raising a plant in an environment that isn't the flower's natural one, even if it is a hybrid that has been groomed to accept a non-natural condition, is that all of the other conditions become increasingly important. So, soil, mulch, fertilizer and watering become that much more critical when raising clematis on a north facing wall. There is an old saying about clematis, 'Tops in the sun and feet in the shade', and this even holds true when the top is a little shaded also. It's often recommended to mulch clematis deeply and even grow some other low growing plants around it's base to keep the roots protected. Clematis is known to respond well with fertilizer, and with a shaded plant, you'll want to feed the soil every 4-6 weeks, around the base of your square trellis.

So, basically, to conclude the question, can clematis be grown in shade? Yes, you can have that clematis trellis in the shade. Next, maybe a raspberry trellis, in the shady part of your yard, or on that north facing wall.