You don’t have to plant the clematis right up against the wall as once they get going you will be able to train them towards it. Aim to plant them about 30cm. (12 inches) away from the wall. Dig out a large hole and fork in plenty of J Arthur Bower’s Organic Farm Manure. Clematis are greedy feeders and will appreciate the extra nutrients. Then plant as recommended for shrubs and mulch with extra Organic Farm Manure.