So here we are into the last month of the year with a definite feel of hot cups of soup and cosy evenings in front of the fire.
With such an onset of midwinter it would be wrong for me not to take this moment to talk about the ongoing developments of the Winter Garden here at Hyde Hall. Due to officially open in 2018, our huge 1.2 acre (0.52 hectare) Winter Garden offers the unique opportunity for visitors to relish in the delights of plants associated with winter, and over the next year we will continue the process of planting shrubs, trees, bulbs and herbaceous material.
So that visitors can get close as the garden develops, our intention is for a solid path to be installed in the early part of 2017 to allow for access. Stem colour, berries, winter fragrance and bark textures play an important role for lifting gloomy days, and as you meander through the shaped mounds, (made from 19,000 tonnes of Hyde Hall soil) we hope you will be mesmerised by the grouping of plants such as Acer, Viburnum, Ilex, Malus, Callicarpa, Hamamelis, Ginkgo, Prunus, Salix and Cornus to name but a few.
It is this last plant, the Cornus or dogwood, a classic winter stem plant, that I have chosen as December’s Plant of the Month. They are also a diverse group and as part of the Winter Garden display we have an RHS plant trial of Cornus with 50 different types being assessed over the next four years.
As the majority of the Cornus are northern hemisphere plants, they can tolerate the cold down to -20°C (-4°F). Positioning is important so that you can capture their winter stem colour, and ideally cornus should be grown in full sun that also offers the winter light. They prefer free-draining soils but here in Essex with our damp winter clay soils they also grow well, especially as they do not like to be dry, particularly in the early years of establishment. Thus the summer dry spells should not be overlooked, as water during the growing season is vital in obtaining good strong growth.
After the first two to three years of establishment it is good to cut back their stems hard, as this encourages new young growth, which is even more vibrant the following winter. We prune here at Hyde Hall usually late March or early April.
In order to maintain genetic stability (i.e. to keep particularly good strains going), both hardwood and softwood cuttings can be used to obtain new plants. The hardwood cuttings are taken during the dormant season just after leaf drop or before bud burst in the spring, however, you will need patience as they can take more than a year to produce roots. Softwood cuttings are taken from the new growth in spring or early summer. These cuttings do offer quicker results, but can be more difficult to keep alive.
Pest and Diseases
Strong healthy cornus plants are generally trouble free, although they can be affected by honey fungus and phytophthora. Dead wood can also get secondary infection with coral spot. The North American Cornus kousa types can also suffer with cornus anthracnose.