How to grow Clematis

  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. 

How to Plant Clematis

Most clematis can be planted at any time of the year. Like all plants, it is not a good idea to plant when the weather is poor, or frosty. To give Clematis a good start, plant Clematis during Spring, Summer or Autumn selecting a time without immediate frosts, a good weather spell and rain after planting is helpful, providing it is not a mini monsoon. This often means planting Clematis from April onwards. 

The golden rule when planting a Clematis is to make sure that the root ball sits at least 5cms below the soil level - see image left. This is beneficial to the plant and helps to stop Clematis wilt. Dig a hole comfortably larger than the pot the Clematis is in. Make sure the soil at the bottom of the hole is not compacted, making it easy for the roots to grow into. Add peat free compost, fertiliser and water. Ease the Clematis out and place in the hole.

The easiest way to make sure you have got the depth correct, and to judge the depth, is to lay a bamboo cane across the hole so you can see the line of the soil depth and check the Clematis is at least 5cms below the soil level. Fill in, water and protect young growth from slugs. Clematis do well if their roots can be shaded whilst the rest of the plant prefers sun, not an easy combination. 

You can protect and shade the roots by the leaves of adjacent plants, such as a large leaf Hosta or by a physical barrier such as a slate, plus mulch will help to keep the roots cooler. In common with all new plants, Clematis should be watered well after planting. A newly planted Clematis will benefit from cutting all shoots down to 15 -30cms the first year only. Watch the Sunday Gardener video How to plant Clematis.

More about Growing Clematis

Once you have planted your Clematis the next step is how and when to prune it. To prune it, you need to know to which pruning group your particular Clematis belongs too. Easy if you have the label, less easy if you have lost the label or acquired the Clematis in a garden which you didn't plant and don't know what it is.

Next steps

Pruning Groups 1, 2 & 3 explained plus How to Prune Clematis.

Pink Clematis in bloom

How to Grow Clematis Key Points

  1. Always plant Clematis at least 5cm below the soil surface.
  2. Plant in moisture retentive, well-drained soil in a sunny position.
  3. Clematis roots should be shaded, by adjacent plants or using a physical barrier.
  4. A mulch will help to retain moisture and keep the roots cool.
  5. Prune according to pruning group.
  6. Provide support for the Clematis

last updated 22.12.2020