CARE AND PRUNING OF CLEMATIS IN SOUTH AFRICA

Introduction
Clematis have been popular in European gardens for centuries and more recently they have been grown successfully in most parts of South Africa. In Spring there are few plants that can match the breathtaking beauty of a well-grown, well-trained and regularly fed clematis! Clematis flowers twice a season, in October/November and again in February/March. The flowers come in a wide range of colours, shapes and sizes (in fact they come in every colour except black!). They can also be single, double or semi-double, small or large. The choice is enormous!


Clematis are  creepers which need support to climb and show off their beautiful flowers. With careful planning they will add a touch of elegance to any garden. They may be trained to grow up trees, shrubs, roses, fences or walls, or, they are splendid when grown in a pot and trained up an obelisk or trellis. You could use three canes tied together to provide a obelisk in the first couple of years.


The majority of Clematis are deciduous and will shed their leaves or go brown in autumn and become dormant in winter. This is quite normal! There is nothing wrong with your plant. Cirrhosa group is evergreen and the only ones to flower in winter.
 
Where to grow
I recommend that Clematis in South Africa be grown in pots until they are at least 3 years old before considering to be planted in the garden. All my plants are kept in pots for over 10 years now. I grow Clematis in full sun contrary to the advice of the "experts"  and have great results. Most Clematis will grow in any aspect (North, South, East or West) as long as they receive sun or semi-shade. I have found that the light pinks that fade easily e.g. Nelly Moser, Bees Jubilee, Lincoln Star, etc. also like full sun, but because they fade to white, I recommend that they be grown in semi-shade or morning sun.  In these conditions they flower profusely and the colours are brighter. When Clematis are grown in full sun, they must be watered regularly and be kept moist.  Roots need to be kept cool, mulching around the plants with bark helps maintain coolness and moisture. I do not recommend planting other plants in a Clematis pot to shade the roots! Clematis are  hardy and can survive extreme temperatures. One must remember that these plants originally came from Europe, Poland, Japan and Estonia where snow covers them in winter. The colder the winter in South Africa, the better the display will be. I have never lost a plant due to black frost.

Planting
Customer feedback and experience show that pot-grown Clematis do far better than those planted in garden soil. There should be only three things in your pot; Soil, Plant and Support.  Do not plant your newly purchased plant in a big pot straight away. Normally you would re-pot from a 18cm to 30cm to 43cm to a 58cm pot. When planting in the ground or a pot, always sink your plant at least 8cm below ground level. Garden soil is not generally suitable for Clematis as it becomes too compact and interferes with drainage. I only use good quality potting soil mixed with a little bone meal.  I do not add drainage material or soil wetting agents. Pots with side drainage holes are preferred. The reason why I do not recommend that you plant them directly into the soil is that you cannot plant them deeper at another stage. Clematis grown in pots can be moved and replanted as required. The deeper planting method ensures that buds below the soil will spring into action should the plant get wilt or when it is pruned. Think of it as an insurance policy. Species Clematis like Montana, Tangutica and Cirrhosa are normally not planted deeper. These groups can be planted into the garden after two years.

Two varieties put together in a 43cm Pot
Two varieties put together in a 43cm Pot
Halfway through the filling process. I have removed all green leaves that will be below soil level.
Halfway through the filling process. I have removed all green leaves that will be below soil level.
Filled up with soil. I have left the original canes in as they will be removed when the Clematis are cut down.
Filled up with soil. I have left the original canes in as they will be removed when the Clematis are cut down.
Three additional long canes tied together to provide support.
Three additional long canes tied together to provide support.

 

Pruning
Most of the questions I am dealing with is with pruning. I will attempt to make this as easy for you as I can.
 
Prune all Clematis in Group 2 or 3 down to above the first pair of inter-nodes the second weekend in July  for the  first three years.


Double Pruning Method:

Because of our longer growing season in South Africa, you may decide to double prune. Double pruning is where you prune twice a season. Once in the middle of November and again in July. When you prune in mid July, keep on finger pruning until the 1st of September for Group 2 and up to two weeks later for Group 3.. Flowering occurs roughly 6 weeks after your last finger pruning.

 
At pruning time you could also consider to re-pot your plant. Should you decide to re-pot, you could either then bury the pruned clematis under ground or prune down to the 3rd inter-node and bury the plants up to this level in the new pot. Where a variety only bloom double on old wood (normally part of Group 2), I would still recommend this pruning practice and after the third or fourth year prune according to the Group2 instruction discussed later. Start feeding your Clematis after pruning. When new shoots appear, finger prune.  Finger pruning is where you keep breaking out the center stem of the new growth with your fingers. The plant responds by shooting two side stems. Finger prune these again and for every two stems you will get double. This practise make the plant bushy and florific.  After this, just feed the clematis and tie in the new growth.  This method will ensure that you have multi-stemmed Clematis and stronger and healthier plants with a show of flowers the  middle of October (or Febuary if you double prune).

 

It is important to remove the seedheads from the plant after flowering. This ensures that the plant puts its energy into making new shoots/ flowers and not into seed production.


After the fourth year you can prune according to the International agreed codes if you wish:
 
Code 1: Flowers on last year's wood (e.g. Montana & Cirrhosa groups)
DO NOT PRUNE!
  (Cirrhosa can be lightly cut back after flowering)
 
Code 2: Flowers  on old and new wood
Remove weak growth
Cut all dead leaves and tendrils from all stems
Rearrange the bare stems and retie to the support

 Code 3: Flowers on new growth (e.g. Florida, Heracleifolia, Integrifolia, Recta, Tangutica, Texensis and Viticella Groups)
In July cut back almost to ground level

 

I Double prune all my Clematis in Group 2&3 every year except for the one's who only double flower on old wood and that are older than 4 years.
Should you not know to which pruning group your plant belongs to, look at the flowering time and foliage of your plant. Species have normally very different foliage and can be easily identified.
 
Should you decide to plant two or more varieties together, it is advisable to select plants requiring the same pruning method and vigour to ensure a spectacular display. Choose  contrasting colours and or  contrasting shapes for maximum impact.

Feeding and Watering
In the growing season fertilize your plants at least every two weeks, using “Seagrow”, “Nitrosol” or “Multifeed Classic”. Never exceed the manufacturer's dosage. Always feed when the plant is moist. I do not feed when the flowers open as this shortens the flowering time.
 Note: Should you plant your Clematis in the ground remember that they have to compete with other plants for food and water so it would be a good idea to see they get their share!

Stop feeding when plants go dormant (normally April / May).


Flowering Clematis in pots need a lot of water. Should your plant wilt, check the soil immediately to see that it is damp. At the same time remember that Clematis hate wet feet, so do not over water.
If, after watering a dry plant, it doesn't recover quickly, it could have a disease called 'Clematis Wilt'.
 
'Clematis Wilt'
Large flowered varieties are susceptible to 'clematis wilt' but the small flowered clematis are usually resistant to the disease. Symptoms of the disease include sudden wilting and collapse of previously healthy stems or the whole plant. To control this disease, cut back the wilted stems below the level of infection, or, if necessary, at ground level. Be careful to remove infected material as fungus can be dispersed very easily. Disinfect any tools. No effective chemical treatment is available at present. Wilting very rarely results in the demise of the plant!
 
Pests
The most common pests are snails, slugs and insects such as aphids, white flies or red spider. Some Texensis varieties may be prone to mildew. If any of the above is a problem,  spray accordingly or apply a systemic insecticide and or fungicide. Any product intended for Rose care is also suitable for Clematis.
 
Please do not hesitate to contact me should you experience any problems.