Monthly Masterclass: September

Identify it: Clematis Wilt


Step 1

A healthy Clematis 'Forever Friends'

A healthy Clematis ‘Forever Friends’

Clematis wilt is a common problem experienced by many clematis growers. Symptoms include blackening of the stems and leaves which in turn leads to wilting and eventually death, frequently over a very short period of time. True clematis wilt (Phoma clematidina) is a fungal infection. Often clematis present comparable symptoms even when the fungus is not present. In these instances wilt is likely a result of environmental stress.


Step 2

Prune wilted material back to healthy growth disinfecting secateurs after use

Prune wilted material back to healthy growth disinfecting secateurs after use

When our pergola was re-planted two clematis were included in the design; C. ‘Etoile Violette’ and C. ‘Forever Friends’. Less than twelve months later both are showing signs of wilt. Here, the clematis have struggled to establish. They have endured long dry spells followed by waterlogging where the pergola has proved inadequete at draining away heavy downpours of rain. To compound the problem, in some areas the pergola foundations are particularly shallow, severely restricting the potential root run.


Step 3

Bagging unhealthy clippings will help to prevent the spread of clematis wilt

Bagging unhealthy clippings will help to prevent the spread of clematis wilt

Prevention is usually better than cure. Avoid planting those hybrids derived from C. lanuginosa which have proved acutely susceptible to wilt. Instead, opt for smaller flowered species such as C. montana or C. tangutica which have shown some resistance. Always plant clematis 15cm deeper than in their pot to encourage strong, healthy roots further up the plant. Where wilt does occur, prune back to healthy growth and dispose of somewhere the infected material will not contaminate other plants or compost. Clematis roots often survive so it is worth waiting to see if new growth appears again before digging out a plant completely.


Grow it: Agapanthus

What: Agapanthus, or African Lilies, are half hardy and hardy perennials which flower most frequently blue but also white, pink and purple, and range in size from as little as 40 centimeters to well over 1 meter in height.

Where: A native of South Africa, Agapanthus  appreciate a sheltered position in full sun with lots of good drainage. Grow hardy species at the base of a south or west facing wall and incorporate plenty of gritty compost. Half hardy species can be grown in pots and given winter protection in a cool greenhouse or beneath fleece.

Some Agapanthus have individual flowers which are striped two different colours whilst others exhibit a more subtle gradation of colour

Some Agapanthus have individual flowers which are striped two different colours whilst others exhibit a more subtle gradation of colour

How: For many years it was thought that Agapanthus flowered better when left pot bound and neglected in a container. Most gardeners now agree that this is not the case. Pot up as normal and feed well with potash throughout the growing season.

When: Plant out into beds in spring or autumn before the frosts arrive and divide congested clumps before or after flowering in spring or early autumn.

The Gardeners Verdict:

“I like large Agapanthus cultivars, but think the smaller cultivars lack drama, which defeats the object of an Agapanthus to me! They’ve got it all…strongly architectural flower heads, a good range of colours and individual flowers which repay closer attention. The season of interest is prolonged by their seed-heads, and they have lovely bold strappy leaves too!

Because they are such a strong, simple shape with good, clear flowers, Agapanthus can be used in several ways. They contrast well with the soft forms of other plants and give good structure. One of the best combinations I have seen is on a round-about planted with hardy palms, Tulbagiaviolaceae and Agapanthus!

In a south-facing herbaceous border they can be paired with complimentary colours such as pink (Geranium ‘Pink Penny’), lilac (Thalictrum delavayii ‘Hewlett’s Double’), or white (Gypsophila paniculata ‘Bristol Fairy’).

Alternatively you can contrast dark blue Agapanthus such as A. ‘Midnight Star’ with yellow, orange and red Crocosmia (Crocosmia ‘Jenny Bloom’ , Crocosmia ‘Emily McKenzie’ and Crocosmia ‘Lucifer’ respectively).

If you’ve struggled to grow Agapanthus in the past you could grow Alliums instead which have the same bold flower shape and height. Try Allium ‘Round and Purple’ or Allium christophii. They don’t need as much heat as Agapanthus, but they do like to be in  a sunny spot.”

Abby Gulliver, Glasshouse Area Supervisor, Winterboune House and Garden


Read it: Food for Thought

At the height of the Arts and Crafts movement the production of food in gardens was given elevated status . In August’s Food for Thought we discover how the legacy of that tradition continues to influence the gardens at Winterbourne today.

Food for thought

Food for thought

3 Thoughts on Monthly Masterclass: September

  1. Oddment

    Reply

    Thank you for starting my day with two wonderful photos. Gardens wear blue, yellow and white so well together! And the squash — isn’t it wonder how beautiful vegetables can be?

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