In many ways Clematis are easy to grow because they are a vigorous climber, and most are fully hardy tolerant of many soil types and conditions.
What makes Clematis a little tricky to grow is mainly the fact Clematis need regular annual pruning every year apart from Group 1. That in itself can be a problem to know if your Clematis is group 1,2 or 3 which determines its pruning requirements. All Clematis in groups 2 & 3 to maintain shape and flowers need pruning every year. This makes Clematis an "amber wheel barrow plant" indicating medium difficulty to grow. In addition, for newly planted young plants and at the beginning of the growing season, the spring growth is attractive to slugs and Clematis need protection. Tips on how best to protect Clematis from slugs. Lastly, Clematis can be subject to a disease called Clematis wilt, by which the leaves turn brown and look unsightly.
On the positive side, Clematis are a lovely and very popular climbing plant with a wide range of flower shapes, sizes, colours and flowering times. The Pinterest page and Types of Clematis illustrate the many diverse shapes and sizes of Clematis, with new varieties being introduced every year.
The easiest Clematis to grow, because they need little or no pruning are Clematis montana, C. alpina and C. macropetala. One of the loveliest varieties, Clematis montana 'Elizabeth' has a beautiful vanilla scent. Of all the Clematis, when planting a Clematis montana you need a large space as many varieties are vigorous growing up to 15m (nearly 50ft) if left unchecked and growing in ideal conditions. However, there are now varieties of Clematis montana which are less vigorous and manageable in the average sized garden- check out Types of Clematis for more information.
The different varieties of Clematis have a long flowering season, staring early in the year with the C. alpina right through to September the late flowering C. Tangutica, and over winter C. Cirrhosa. Clematis like well-drained soil with sun or light shade. There are some Clematis varieties which are more shade tolerant listed below.