The Newnham Naturalists – Winter Flowering Shrubs

Hamamelis ‘Arnold Promise’

Over the past few weeks, several people have commented on the amazing scent as they have walked through one corner or another of the garden.  Flowers of winter flowering shrubs are usually relatively small because they have to be able to survive the rigours of frosts, but many have a strong scent which is carried on the air in order to attract early pollinators, and so it is often the case that you can smell them long before you see them.

The plant I think most people are noticing is Sarcococca, which is planted fairly extensively here at Newnham, often near doorways and along the buildings. There is a huge bank of it at the far-end corner of Peile which is filling the air with its wonderful fragrance at the moment. This is Sarcococca confusa, a compact evergreen shrub with tiny, very fragrant creamy white flowers followed by black shiny berries.  It is a very useful groundcover plant, tolerant of ‘shade and neglect’ according to the RHS, and can also be clipped.  There are several other species, including S. hookeriana, Himalayan Sweet Box, which also grows here, and has creamy white flowers with crimson anthers, and S.ruscifolia, which has red berries.

Another wonderful winter scent is the spicy sweet smell of Chimonanthus praecox, Wintersweet. It is a spreading deciduous shrub that can grow to 3m across, which is best planted in front of a sunny wall for maximum flowering between December and February. The flowers are very unusual, pale creamy yellow and waxy looking, with streaks of maroon on the inner petals, and the fragrance is stronger in the species than in the cultivars. At Newnham, there is one planted next to Sidgwick, and another at the back of Old Hall, and on sunny winter days, the scent can carry all the way across to the back of the Pightle.

Equally fragrant are the beautiful spidery yellow or orange flowers of some of the Witch-Hazels, Hamamelis sp. In the wild these elegant deciduous shrubs grow in scrub and woods, so are best planted in soil rich with leaf mould in partial shade. At Newnham we have Hamamelis x intermedia ‘Arnold Promise’, (named after the Arnold Arboretum in Massachusetts where it was raised) growing in the Peile border and behind Old Hall, pictured. Growing to a height of about 4m, its prolific bright yellow flowers have a strong fragrance, followed by colourful autumn foliage. Other good garden varieties include H. intermedia’ Pallida’, with yellow fragrant flowers and planted along the border of Grange Road,  and ‘Jelena’ with coppery orange flowers, recently planted at the far end of the Nutwalk.

But my absolute favourite is the intoxicating fragrance of the Daphnes, evergreen and deciduous shrubs from the Thymelaeceae family, several species of which are grown for their fragrant terminal clusters of flowers. At the end of the Nutwalk the amazing smell is produced by the white pink flowers of Daphne bholua ‘Jacqueline Postill’, also growing in the border along Clough. This is a fairly upright evergreen shrub that grows to around 2.5m, which makes it a good option for small gardens, but should be planted in a sheltered site, as it will not tolerate temperatures below -5 for long. Growing further along the Nutwalk, and reliably hardy is D. odora  ‘Aureomarginata’, which has pink flowers clustered between its shiny evergreen leaves, edged with gold, and grows to a rounded bush, 1mx1.5m. Also reliably hardy, D. laureola, a bushy evergreen species which has fragrant pale green flowers in the early spring is and is a useful plant for growing in dry shade under trees. Daphnes are slow growing and so are often expensive.  They are deep rooted so do not thrive in containers (other than some of the alpine species), should not be moved once established and are best planted in the spring. Most prefer neutral to slightly alkaline soil, although D. blagayana, arbuscular, pontica and tangutica are all lime intolerant.

Newnham’s Big Garden Birdwatch

The RSPB’s Big Garden Birdwatch is the world’s largest garden wildlife survey. During a specific weekend every year, participants record the birds landing in their gardens during a one hour time period, counting the maximum number of each species seen at any one time. Over half a million people now regularly taking part and the scheme has allowed the RSPB to amass almost 40 years’ worth of data. This valuable information helps the charity to monitor trends in populations and distribution, so they can spot problems and plan the steps they need to take to put things right.

Members of CU Nature Society did Big Garden Birdwatches at their respective colleges over the period 27-29 January, and there were prizes for species abundance and richness. The Newnham Garden Birdwatch was carried out by three Natural Sciences undergraduates, Hannah Whitaker, Laura Spencer and Bryony Yates. We’re pleased to say that Newnham had the highest species richness and we have been awarded a certificate!

The Newnham Garden results were:

Robin 3, Blackbird 4, Magpie 1, Woodpigeon 7, Song Thrush 1, Chaffinch 1, Blue Tit 2, Goldcrest 2, Wren 1, Coal Tit 1, Carrion Crow 1.

11 species in all, overall abundance 24. We also had several Jackdaws and some Black-headed Gulls flying over.

Bryony Yates

Moth Trapping

We have been running a moth trap at Newnham since June 2016 and in that time have identified 168 species of macro moth. For us, it was about comparing diversity of species in different environs; the varied habitat of Newnham College gardens against a suburban, rapidly becoming urban garden in Trumpington. Though it is too early to tell much from the data, we are finding some interesting species appearing here that we would not expect to find in Trumpington, even using an inferior light source.

One of the best of 2017 was a female puss moth (Cerura vinula) that obligingly laid 50 or so eggs. These hatched 10 days after she, pictured in the gallery below, was trapped in May, and the larvae were raised with most being released at various stages of growth onto Grey Poplar suckers in the Nutwalk. Six were kept and pupated, and we are now waiting hopefully for adults to appear sometime this May.

Our records are now with the County moth recorder and will be fed into the National Database and used to monitor population health. Being a bit of a moth freak I find all aspects of these wonderful creatures fascinating, though I cannot deny most people I know think I should get out more!

Chris Thurgood