Clematis 'Vince Denny'

Clematis of the Month for February 2023

described by Brigitta Niemela

[Editor's note: Clematis 'Vince Denny' is featured this month to celebrate the recent 100th birthday of Sylvia Denny, wife of the late Vince Denny. For more information about Vince and Sylvia, please see the additional information by Fiona Woolfenden after Brigitta's article.  I thank Brigitta and Fiona for writing such an interesting Clematis of the Month at short notice!]

C. 'Vince Denny'

How Clematis 'Vince Denny' came to my garden

A long time I have admired the beautiful photos of C. 'My Angel' on the web or in gardening magazines. However, it didn't fit at all in the color scheme of my garden which is dominated by cool colors in pink, purple and blue. I do have an area which is separated from the rest of the garden where I have plants in warm colors of red and yellow. The problem was that this is a very small corner. I knew that C. 'My Angel' is a strong grower and it would be too big for this limited space. One day I came upon a description of C. 'Vince Denny', saying it was like 'My Angel' but with a more moderate growth habit and it does not produce underground runners.

Looking up into the beautiful flowers of C. 'Vince Denny'

Growth habit

As C. 'Vince Denny' has been in my garden for only two years, I don't allow myself to give a final verdict on its growth habit just yet. So far it is a good and bushy grower which climbs up to 2.5 meters. It is a deciduous liana and belongs to the Tangutica Group. One of its parents is C. intricata. "Intricata" is Latin and means entangled or intertwined. Wild growing C. intricata form muddled bunches that hang over rocks and bushes. C. 'Vince Denny' obviously has inherited this growth habit. Its petioles seem to be not very touch sensitive, because they don't form many tendrils. Instead of embracing its support and pulling itself upwards, it rather tends to lay itself over the support. This makes it an ideal candidate to grow i.e. over a low fence.

C. 'Vince Denny' likes to lay the shoots over a support

Stems and leaves

The smooth and green stems are often tinged with mahogany purple especially around the nodes. Between the nodes there is a relatively large distance of about 20 cm.

The leaves are pinnate with 5 to 7 leaflets. Their silvery, greyish green color is reminiscent of the leaves of an olive tree. You find lanceolate, elliptic and ovate leaflets. Some of them have 1 to 3 lobes. The leaf margins are mostly entire. A few leaves have scalloped margins.

Part of a stem reaching out to intermingle with C. 'Diamond Ball'

Buds and flowers

The nodding buds are globular with an appointed tip. Their initial lime green color soon turns into a very dark hue somewhere between purple and mahogany.

The nodding buds turn their color

Non-stop production of flower buds

The nodding campanulate flowers always consist of four tepals. They open widely with recurved tips to present their striking stamens and pistils. But the bees know long in advance that there is something to get in here. It is funny to watch them squeeze into the just opening bells.

Hurry up, before another bee gets the sweet pollen

There is a strong contrast between the dark mahogany on the outside of the tepals and the bright yellow of the inside, that gets visible at the margins. The tepals are fleshy and coarse, giving the impression of being made up of a dark and a bright layer.

The fleshy tepals look like they have two layers

The tepals are yellow inside. Brown veining is visible when wide open. Stamens and pistils are very prominent. The yellow pistils are very long and surrounded by elegantly looped, dark brown stamens.

The conspicuous pistils are nearly as long as the tepals

When the flowers are widely open the brown veining on the inside of the tepals gets visible

Seed heads

The seed heads are a further attraction of this plant. Since the flowering period extends over several weeks, you will find flowers and seedheads at the same time. Smooth and silvery at the beginning they become plumose pompons towards the winter. Imagine them covered with hoarfrost – a real winter dream.

At the beginning the seed heads are smooth and shiny

Roots

The plant has a fibrous root system. No need to plant it deeper than in the pot.

Care and pruning

C. 'Vince Denny' is a robust and resistant plant. It grows well even in sunny conditions and can be planted on the south side. Very good winter hardiness.

If space is limited in your garden, give C. 'Vince Denny' an annual hard pruning. But this is not a must. You can leave it unpruned several years, if you want to cover a larger area.

Enjoying the support of the Rose 'Lady of Shalott'

Made for natural garden styles

The earthy colors of the flowers and the attractiveness to pollinators make C. 'Vince Denny' an ideal plant for gardens designed in a natural style. It flowers in August and September – a period when insects often struggle to find sufficient food.

In natural gardens there is not much tidying up in autumn. Fruits, grasses and seedheads are left standing and provide food and shelter for animals in winter. The silvery seedheads of C. 'Vince Denny' can make an important contribution to the winter aspect of the garden.

The silvery seed heads are an enrichment in the winter garden

C. 'Vince Denny' – a climate winner

Clematis are widely known as heavy drinkers and feeders. With this image, they are often labeled as climate losers. It should be stressed that this is not true for all clematis. There are clematis species from dry and hot territories around the world. Many of them are well prepared for climate change. The Tangutica/Orientalis group offers a large reservoir of plants that are well adapted to future needs. And it is not the only group. Others are, for example, the Flammula, Texensis and Viticella Groups. This is a topic that should have much more importance in the discussion.

With C. intricata as one of its ancestors, C. 'Vince Denny' has good genes to cope with summers that get hotter and drier. According to Magnus Johnson, its habitat are "dry, rocky localities, sunny thickets, steppes, often along streams and river banks to 2800 m elevation". ^{See note 1}

Note 1 - Johnson Magnus, The Genus Clematis, Södertälje, 2001

Brigitta Niemela

Additional Information about Vince and Sylvia Denny - Fiona Woolfenden

The late Vince Denny bred a number of clematis, with C. 'Sylva Denny', C. 'Broughton Bride', C. 'Broughton Star' and C. 'Vanessa', probably the most well known of his cultivars. Vince was a passionate Clematarian, always wanting to share his knowledge and help others. Vince bred C. 'Vince Denny' in 1992. After hid death in 2001, Sylvia named it after him in 2002 and Shelia Chapman introduced it into the UK in 2003.

Vince Denny talking at a British Clematis Society Event

Sylvia Denny with the late John Treasure

I knew Vince and Sylvia, and Sylvia after Vince's death, for a number of years although we have now lost touch. She is a lovely lady. Photos of Sylvia are hard to find although she was always there in the background supporting Vince. We wish her a very Happy Birthday and hope she enjoys her 100th birthday card from King Charles III!