Monday, 15 December 2014

Mahonia in the winter garden

Mahonia x media 'Buckland' after a frost
Mahonia seems to have found its way into the average British garden by means of some terrible mistake. For most of the year it stands about stoically, back to the wall, looking stately and rather prickly – like a sentry whose presence you are grateful for, but whose existence you can more or less ignore. But in late November, at the very moment when most people are barricading the back door against the onset of winter, it starts to do its thing, flinging out sprays of acid yellow flowers in a desperate attempt to attract some attention, and come Christmas week it will still be going strong.

Too late, for most of us humans. But this bothers the mahonia not one jot. What seems to us, with our anthropocentric point of view, a terrible waste of flowering activity is, from the plant’s perspective, a cunning and opportunistic plan to capitalise on a gap in the garden calendar when flowering plants are thin on the ground. As such, the mahonia is one of the key plants in the winter garden for providing nectar for pollinating insects like the buff-tailed bumblebee, one of the latest bumblebee species to seek hibernation. By the winter solstice, even the daftest young queen bumble should have sought a cosy hole, but still the flowering continues.*

The mahonia you’re most likely to encounter in the garden will be a variety of either Mahonia x media ('Charity' and 'Buckland' being two of the most popular and reliable), or Mahonia aquifolium. The latter tends to flower in summer, fruit in autumn, and has more of a tendency to sucker than an inclination to remain a statuesque specimen. Both have rather long, compound leaves, the individual leaflets bearing a marked resemblance in shape to a holly leaf – just as prickly, in the case of M. x media, although a paler green and less glossy**. The leaves of M. aquifolium are a little more pliable and of a darker green shade, often colouring to a wonderful, bright red.

Mahonia aquifolium
If you have one of these, it’s likely that after a few years you might be tempted to give it a prune – they grow larger and faster than you might expect. Fortunately for the owner of the average small to medium garden, they are also markedly forgiving of all but the most ham-fisted hackery, although if significant pruning is required is it is best done over two or three seasons to avoid traumatising the poor plant. Generally, though they may take a year or two to return to their former glory, they will recover well from hard pruning. As with everything, it’s far better to make yourself aware of the size of the mature plant and make your selection accordingly – though I must admit this advice can often come across as smug and untimely if you either inherrited a monster with your garden, or were unaware of such helpful maxims when you bought and planted it five years ago. One thing that does make pruning mahonias a joy is the colour of the cut wood – an unexpectedly rich, turmeric yellow, exactly as with Berberis to which the mahonia is particularly closely related.

The fun doesn’t end when the flowers finally give way to fruit, as the berries are edible (Mahonia aquifolium, a native of Northwest America, is known as the Oregon Grape), though a bit sharp. They are best made into a jam or jelly, and in her splendid The Thrifty Forager Alys Fowler also recommends putting them into pies or making a cordial from them. Needless to say, I’ve not done any of the above (my one and only attempt at making jam resulted in a substance only slightly less solid than tarmac – I nearly broke the spoon trying to get it out of the jar), but I’m perfectly willing to accept an invitation to tea from someone who has.

And while I'm waiting for that invitation to arrive, I shall be strolling outside in my garden, enjoying my mahonia in all its blooming glory. And feeling sorry for my neighbours, gasping for breath in their overheated homes.

*Since first publishing this blog post it’s come to my attention that the Buff-tailed bumblebee (Bombus terrestris) has exhibited a change of behaviour over the last decade or so, and some colonies are able to survive throughout milder winters. A project exists to record more data on the phenomenon of winter active bees, managed jointly by Dr Tom Ings at Anglia Ruskin University and the Bees, Wasps & Ants Recording Society (BWARS). More information, including a link where you can record sightings, is available here.

**If you’re the kind of person who must have the Latest Thing, it’s possible that you may have been tempted to part with (rather a lot of) your cash for a specimen of Mahonia eurybracteata subsp. ganpinensis 'Soft Caress'. This was announced as the RHS Plant of the Year at Chelsea in 2013, and one local trade nursery bought up several acres of the things. With long, soft, spineless leaves, and reaching a final size of not much more than a metre tall and wide, they look rather more like a nandina than a mahonia. Quite pretty, and certainly a novelty. But if it ain’t big and spiky, it ain’t a mahonia, if you ask me.