The December Garden 2023
I love the optimism of my RHS ‘Gardening Through the Year’ book in which it says that December can be a wonderful month in the garden. Also that although the days are short, on the whole the weather is not too bad, with wonderfully clear, frosty, sunny days when it can be a pleasure to be out! Well let’s all hope that this December follows the script so that we can get out into the garden to enjoy the delights on offer. There may not be the abundance of growth and flower of the earlier months but there are still lots of interesting details to catch the eye. For example on a late November afternoon when the sun came out, all too briefly, I was able to find the following plants doing their best to brighten up the winter days.
Some very late flowers of Campanula and Astrantia
Japanese Acers in twig and leaf
A late flowering Hardy Geranium and the fading glory of a Lacecap Hydrangea
Mahonia flowers enjoying some winter sun and the buds and flowers of Viburnum x bodnantense
Looking back through past December blogs I see that in 2020 I was recommending some good ‘winter’ plants under the headings- ‘Flowers’, ‘Promise of Buds’, ‘Foliage Colour’, ‘Branches and Twigs’, ‘Seed Heads’, ‘Stem Colour’ and ‘Evergreens’. In addition there was a section on December jobs with particular emphasis on the winter pruning of trees, shrubs and fruiting plants. December 2021 should have come from the gardens at Aberglasney but unfortunately I was unable to get there in late November due partly to my back not playing ball and then Storm Arwen making an appearance! Instead I concentrated on plants in our own garden most of which were also featured in the 2020 blog. In 2022 I was singing the praises of five plants associated with Christmas- Christmas Box, Christmas Rose (Helleborus niger), Christmas trees of various kinds, Christmas Cacti and Christmas Peppers.
For this December I thought I would concentrate on three native plants which we all associate with Christmas and which many of us will be using to decorate the house for the festive period- Holly (Ilex), Ivy (Hedera) and Mistletoe (Viscum album).
The Ilex genus is one of over 400 species of evergreen and deciduous trees, shrubs and climbers from woodlands in tropical, sub-tropical as well as temperate regions. In parks and gardens they are grown for their foliage and berries. The leaves can be entire but most are spine-toothed (many small spines) or spiny (fewer but larger spines). Flowers, borne from spring to early summer, are produced singly or in clusters in the leaf axils (where the leaves join the stems). They are small, cup-shaped, with 3-8 petals and are most usually white or cream but may be pink, green or lavender-blue. Male and female flowers are usually borne on separate plants so both are needed to produce fruits, which in temperate climates occur in the autumn. They are mainly red or black but some plants produce white, orange or yellow berries. Our common Holly is Ilex aquifolium, female versions of which produce long-lasting berries which together with the spiny, evergreen leaves makes it a very attractive plant for Christmas decorations. Ilex aquifolium also has many cultivars some of which are female, others male and some of both sexes. Some also have variegated leaves in white, cream and gold. Most cultivars have red berries but for yellow berries look out for Ilex aqui. ‘Bacciflava’. Unfortunately the cultivar names are not always a good guide to the sex of the plant, for example Ilex aqui. ‘Golden Queen’ is a male and Ilex altaclarensis ‘Golden King’ is- you guessed it- a female! Fortunately most plants these days come with detailed labels on which the sex of the plant should be clearly shown. If all this talk of sex is just too much for you then you can always look out for self-fertile plants which have both male and female flowers on the same plant. Good ones to consider include I. aqui. ‘J C van Tol’ and I. aqui. ‘Pyramidalis’.
Two large male Hollies at Aberglasney // Ilex ‘Golden King’ proving that she is female!
Hedera (Ivy) is a much smaller genus consisting of around 10 species of evergreen, woody-stemmed, trailing or self-clinging climbers. They are found in light woodland or on trees and rocks in N. Africa, the Canary Islands, the Azores and Madeira and from Europe to the Himalayas, China, Korea and Japan. Interestingly Ivies show two quite distinct stages of growth. In the creeping or juvenile stage they have adventitious roots (roots which form along shoots above ground), lobed leaves and hairy young shoots. In the adult stage they produce aerial ‘bushes’ with entire, usually broad, ovate leaves and in autumn spherical umbels of tiny, 5-lobed, yellowish-green, bisexual flowers which are a vital source of food for many insects at that time of year. These are followed by spherical, black, sometimes orange or yellow fruits which are a valuable source of food for many bird species as well as providing colourful Christmas decorations for we humans. Hedera helix is the Common or English Holly which with its vigorous growth, clinging stems and habit of trailing and rooting across the ground is unsurprisingly not a popular garden plant! However, it now has many cultivars (well over 50 in my reference book) which are much better behaved and therefore more suitable for garden use and in some cases as house plants. Many are variegated in cream, yellow or white while some have completely yellow leaves such as H. helix ‘Buttercup’, others have dark green leaves which turn deep-red-purple in cold weather such as H. helix ‘Glymii’. Other species such as H. colchica have larger leaves and H. hibernica, the Irish Ivy, is a vigorous climber with 5-lobed, dark green leaves and is ideal for covering larger walls or as a fast-growing ground cover. Ivies in general are valuable plants for forming an evergreen backdrop for other plantings as well as for covering walls, fences and even unsightly buildings. Variegated plants are also useful for lightening up dark corners where little else will grow. Wall grown Ivies will not damage sound brickwork but they may dislodge loose mortar and discolour paintwork on wood or stone.
Hedera helix at Aberglasney doing what it does best and its berries
Mistletoe, Viscum, is a very different plant, being a parasitic shrub. The genus contains just under a 100 species of woody, partially or semi-parasitic plants. They have a unique strategy of acquiring nutrients through a combination of their own photosynthetic activity and the absorption of materials from their hosts. As such they are known as ‘obligate’ parasites as they are unable to complete their life-cycle, ie. produce flowers and fruits, without attachment to the host. These hosts are woody shrubs and trees and different species of Viscum tend to parasitise particular host species although most are adaptable to a number of different hosts. Our native Mistletoe is Viscum album which forms large, spherical masses of stems, foliage and berries up to 1m wide in the tops of trees, all of which are very obvious on the otherwise bare branches at this time of year. Just be aware though that all parts are poisonous- they are for kissing under, not eating! The leaves are oval and grow in pairs while the flowers are small and white, made up of four tiny petals and form in clusters of three to five. Mistletoe is, like Holly, dioecious meaning that the male and female flowers are produced on separate plants. For us, of course, in terms of Christmas it is the berry which is of interest. They are waxy and white, grow in clusters of two to six and are around from October until as late as May. The seeds inside are coated with a sticky substance which attaches to the beaks of birds feeding on the berries. Many of these are thrushes in general rather than just the Mistle Thrush in particular and they help to spread the seeds by either wiping them and the sticky substance off onto a branch or by eating the berries and excreting them later onto branches. Gardeners who are lucky enough to have suitable host plants can replicate the former, but definitely not the latter process!, by rubbing berries into cracks on branches and then being very patient as nature works her miracles. The sticky substance on the seed hardens and fastens it to the branch and later as the seed germinates the roots penetrate the bark and begin to take water and nutrients from the host. The most popular hosts are Apple, Lime and Poplar but Mistletoe can also be found on Blackthorn, Hawthorn, Rowan and Willow. Mistletoe has long been associated with myths and symbolism. In Greek mythology heroes were granted passage to the underworld with Mistletoe. For Druidic societies the plant was believed to give protection against evil and act as a cure for disease and right through to the Middle Ages it had associations with fertility and virility-so be careful! Don’t forget also that kissing under the Mistletoe comes with rules- a berry has to be removed for each kiss claimed!
Where we live there is a distinct shortage of Mistletoe, I imagine because we have few of the host species of tree. Our good friend from Worcestershire has therefore kindly sent these photographs of the Mistletoe in her local park.
I end with the final recommendation for ‘Bee Friendly’ plants from the RHS and you won’t be surprised to see that it is the wonderful Mahonia japonica as shown in one of my earlier photographs. With their holly-shaped, pinnate leaves (compound leaves with leaflets arranged either alternately or in pairs along a central axis) and clusters of vibrant, yellow flowers these evergreen shrubs aren’t fussy about their growing conditions and offer a welcome snack to bees roused into activity on warmer winter days. Other ‘good’ nectar plants at this time include Helleborus foetidus (the Stinking Hellebore- don’t worry, it is the root which has the pungent odour), the winter-flowering Honeysuckle (Lonicera fragrantissima) and, maybe more for the countryside than for gardens, Gorse (Ulex europaeus). Where we live the Gorse seems to be in flower every month of the year and is not only a ‘good’ bee plant but is also a great habitat for many of our small birds.
That’s all for this month and, of course, for this year but I will be back in January to look forward to the new gardening year ahead. Until then it just remains for me to wish you all a very happy Christmas and, as always, an enjoyable time in your gardens.
Keith.