Gardening – Winter warmer.

By my reckoning, we are now on the edge of winter. Gardeners and meteorologists tend to consider winter to be the three coldest months of December, January and February. For the gardener, these months are not just cold on the temperature front, but also on the flower colour front. You see, we get spoiled by the fiery leaf colours of autumn. Dazzled by the reds, oranges, and yellows of those tall garden dwellers, Maple, Beech, Ash, Mountain Ash, Hazel, Oak, Birch, and Chestnut, to name but a few. But after the wild party comes the hangover which, in many gardens, leaves us without colour once all the bright leaves have fallen. The savvy gardener will have foreseen this barren period, however, and will have added plants to their garden that give it a lift over the winter. Have you done so? If not, or you feel you may be a bit lacking in colour at this time, then read on. Now I know there are winter bedding plants, Ornamental Cabbage and the like, that you can add for a splash of colour, but I am thinking more long-term. There are a fair number of repeat performers in the shrub and perennial world which you can plant once, then leave them to perform winter after winter. Mahonia aquifolium is one of those, also  known as the Oregon grape. I call Mahonia my winter warmer as it can be used to brighten up those areas of garden normally darkened by the short winter days. Some of you may know it by its other names, the holly-leaved Berberis, the holly grape, or the Oregon grape. The Oregon grape name comes from the rocky slopes of Oregon in the United States where this grape-berried shrub can be found growing wild. Mahonia aquifolium is commonly regarded as a groundcover planting due to its moderate size, growing to a height of 1 metre and a spread of 1.5 metres. You will experience little if any lack of light problems when planting this waist-high shrub next to a kitchen or sitting room window. This is great because it will allow you to enjoy its bright winter flowers from the centrally heated comfort of your house. Its bright yellow flowers arrive in crowded clusters during spring, bringing their faintly sweet scent with them. Of course, the more of these Mahonias you plant, the stronger that scent will be. To be honest, Mahonia aquifolium should be planted in clusters of fives, sevens, and nines to truly have an impact within a garden, and at 60cm(2ft)spacings, that's easily attainable. The 'grape' in the 'Oregon grape' common name comes from the bloom-like blue-black berries (0.3 inches to 0.5 inches in diameter) that arrive after the flowers. They are not true grapes, you can't make wine from them, but your garden birds will love you for providing them. Initially appearing as green fruits in late spring, whether they get to achieve their blue-black colour in late summer is down to how hungry your birdies are. Where's the warmth? But hold on a minute, I hear you say, you've given us spring flowers and early summer fruit, so where's that winter warming you alluded to? Well that comes from the plants' holly-like leaves, when they feel winter is upon them. They move from being dark, glossy, green coloured leaves in summer, to a warming purple-bronze in winter. This winter coloration happens when, as a result of lowered temperatures, we get decomposition of the chlorophyll in our Mahonia's leaves. This reveals itself to us as additional vibrant pigments or colours, and we are all the richer for it. As an added bonus, any new growth on the plant in spring emerges as reddish or bronze shoots before fully forming to leaves that are 6 inches to 12 inches long, with 7 to 12 leaflets. If I've sold you on the virtues of the Oregon grape, then why not take a visit to your local garden centre or nursery and pick some up before the real winter chills come in. Next week I'll introduce you to another winter warmer to cheer your garden up. Until then, happy gardening and remember that a weed is just a plant in the wrong place.