'Clematis Justa' is a large-flowered clematis with lilac flowers. These flowers appear around May-June and the clematis continues to flower until September. The clematis is winter hardy, but deciduous. Pruning this plant is not necessary, but it can be done if it becomes too large, for example. Because this large-flowered clematis flowers quite early, it is advisable to prune it after flowering. To help the clematis climb better, it needs a little help. It is best to guide the plant upwards along a rack, wire or stick. The clematis does very well in both partial shade and in the sun.