Answer: Clematis prefers to have its "head in the sun" and its roots in a rich moist yet well drained soil that stays cool, so it may not be the best choice for you. Tree roots also create a lot of competition for both moisture and nutrients so you might want to consider some slightly more resiliant plants. A four foot trellis, however, is rather small for most perennial vines. For the sunny spot you might consider the red-flowered honeysuckles such as Blanche Sandman or possibly the orange flowered trumpet creeper (Campsis radicans) which can be pruned back very hard each spring to try to keep it small, the perennial sweet pea (Lathyrus latifolius), or any of the annual vines which bloom so profusely. For the shady spot, you might experiment with the fall blooming clematis (this has fragrant white blooms in the fall and is trimmed back very hard each spring) or possibly one of the semi-creeping plants from the Euonymous fortunei group such as "Emerald Gaiety" since these can be trained easily onto a trellis. If you like these, you could plant them in the sunny spot, too. No matter what you plant you should try to add a good amount of organic matter to the soil and water it well until it becomes established. A layer of organic mulch is also a good idea as it will help keep the soil moist and cool and help feed the soil as it breaks down. Remember too to water deeply less often rather than by a daily light sprinkling.
Q&A Library Searching Tips