Our trainee, Caroline continues her series of gardening blogs following a visit to Harlow Carr as part of an RHS Partner Gardens Event.
The winter garden at RHS Harlow Carr was started by Matthew Wilson in 2006 so it is now 10 years old but it has been extended and the planting amended and there are still plans to develop the garden to give it further scale.
As the garden is linear the concept was to start at one end where there is more autumn planting and walk along the path taking in winter through to spring. However, this means you would be walking towards the sun when the plants are better backlit to show off the colours.
The winter garden creates blocks of colours using Cornus and Salix varieties. A popular choice is Cornus Sanguinea ‘Midwinter Fire’, which is a lovely mixture of orange, yellow and red shoots, produced on young stems. Pruning was discussed as it believed that this variety cannot take hard pruning but they have experimented in the garden and have cut them right back to the ground once the plants have got established so after 2-3 years and this has shown to produce the best colouring. Other people suggested just cutting back 1/3 of the number each year to maintain some vigour. Other Cornus species include ‘Kesselringii,’ a black form and lime green Cornus sericea ‘Flaviramea’. The black form combined well with Helleborous niger ‘White Christmas’ and Honesty as an under planting.
As part of the plan for the garden they are going to install a still pool at one end to reflect the plants.
The Salix varieties include Salix udensis ‘Sekka’ which has curious flattened red stems and upright silvery catkins, Salix acutifolia ‘Blue Streak’ which has a blue/white bloom on the stems in winter and masses of silvery catkins in the spring; and Salix gracilistyla ‘Melanostachys’ which is a very eye -catching willow with red anthers and black catkins.
There are blocks of evergreen shrubs added for contrast and individual conifers such as a Japanese cedar, Cryptomeria japonica elegans which changes colour in extreme weather and makes a good feature tree that is soft and tactile to touch. Other trees include Acer davidii ‘Serpentine’ which has ghostly silvery-white lines on the trunk with leaves that turn a rich yellow in autumn. The addition of this type of planting helps creating a warmer micro climate in the garden by adding some height and protection. One of the other gardeners from Woburn Abbey has just planted Acer x conspicuum ‘Phoenix’ which has coral-orange striped bark and highly recommended this plant.
Scent is also important and they use Daphne’s such as bholua ‘Jaqueline Postill’, which starts flowering in January although it loses its leaves after flowering and ‘Penwood’ which gets completely covered in pink flowers and also has a delicious scent.
Under planting includes bulbs such as Narcissus Rijnweld’s ‘Early Sensation’ which starts flowering in January, snowdrops, iris which are good combination with the salix as the Salix help the iris dry out in the summer because the salix takes up so much of the water.
Nigel Dunnett, who has worked on a new masterplan for the garden has suggested they should try and incorporate more summer planting in the winter garden which produce seedheads in winter. They do use Perovskia ‘Blue Spire’ in drifts and leave the stems overwinter which produces a further ghostly effect and contrasts well with the Cornus. They are also planning to develop a bed to provide autumn/winter berries
Heathers have always formed part of the history of the garden as they were originally brought in by Geoffrey Smith because he wanted to link the garden to the external landscape.
There are two main beds, one a river of Calunas which had finished flowering and a larger one of Ericas which formed a painterly palette and was fairly cost effective to established as most were brought in in 9cm pots at a cost of £0.89 each. AGM varieties were used as they are good doers and mainly available. Foliage colour was important to ensure the beds looked as good as possible all year and colours were selected so as not to put exactly the same pinks or purples next to each other. The bees were buzzing round the plants providing good early food. A hand-out of ways to use heathers, including new ways of growing ericas such as planted on a roof, an AGM listing and how to grow heathers was provided.
A chat with Richard Todd from Anglesey Abbey suggested the following for planning and planting a winter garden:
- Make sure all the senses are brought into play and think about where plants are placed.
- Tactile plants such as Prunus serrula are good located next to a path so the bark can be touched.
- Scent is very important he recommended azara microphylla which has tiny yellow flowers and a scent which mixes vanilla and chocolate.
- Separate planting into compartments using foliage plants to create the separation
- Ensure there is good ground cover with no bare earth with epimediums, bergenias, hellebores, carix such as ‘Ice Dance’ and Luzula sylvatica ‘Aurea’