Train Clematis Horizontally . Space the vine eyes 1.8m apart horizontally, then run wire through them. When it comes to pruning, clematis fall into three categories. Clematis armandii Ballyrobert Gardens from www.ballyrobertgardens.com By training shoots horizontally along wires i have ended up with a rather geometric pattern which is quite a feature in its own right. Loosen the soil at the base with a garden fork. Most plants grow primarily vertically, but you.