Pot plants for winter colour
GROW:Container-grown plants can provide splashes of colour and interest in the winter gardenLATE AUTUMN. It seems to have come almost overnight, its arrival heralded by the sudden tumble of toffee-coloured leaves that has blocked up house gutters, covered city pavements and carpeted the country’s roads, shrouding parks and gardens in a cloak of fallen foliage.
Only a few short weeks ago, the unseasonably mild weather meant that short-lived summer bedding displays had held their own, creating strangely vivid splashes of colour in the October garden. Now those same defiant stragglers look doleful and frost-bitten, prompting a non-gardening friend of mine to quizzically inquire why gardeners expend so much effort on summer containers, pots and tubs – but so little on their autumn or winter equivalents.
She’s right, of course. A couple of generously-sized containers filled with a handful of plants chosen for winter interest can make all the difference to the late autumn and winter garden, lifting our spirits and reminding us that spring isn’t really all that far away.
The secret to their success lies in placing the emphasis firmly on colourful stems, bright berries and evergreen foliage, rather than on flowers.
Play around with contrasting textures, leaf shapes and growth habits and they’ll be that bit better again. As always, there are a few other things to keep in mind.
A jumble of mismatching colours is rarely going to be as pleasing to the eye as a carefully thought-out combination. Start off with one key specimen plant and build the rest of the planting scheme around it, using plants that either harmonise or offer dramatic colour contrast.
For example, the tall, twiggy crimson stems of Cornus ‘Baton Rouge’ will make a long-lasting centrepiece to any winter container, offering height and colour but not bulk. It looks especially lovely surrounded with a skirt of evergreen grasses such as the lovely low-growing sedge, Uncinia rubra ‘Everflame’, whose chocolate and cherry-striped leaves will echo the dogwood’s fiery coloured stems.
For extra sizzle, add some pops of colour in the shape of orange winter pansies. If your preference is for containers that are ultra-sleek and contemporary in style, replace the sedge and pansies with a skirt of the sooty-black Ophiopogon planiscapus ‘Nigrescens’, a very low-growing grasslike plant with evergreen foliage.
Alternatively, underplant with the white-flowering winter heath, Erica carnea ‘Whitehall’ which blooms from January to March.
For a brighter, lighter colour combination, consider a yellow-and green themed planting scheme. In this case, the centrepiece could be the lovely yellow-green dogwood, Cornus ‘Flaviramea’, or the golden-leaved, shrubby evergreen, Choisya ‘Sundance’. Underplant with a mix of yellow, chartreuse and green-leaved Heucheras such H. ‘Lime Marmalade’, H. ‘Green Spice’ or H. ‘Lime Rickey’, whose colourful leaves form low mounds of evergreen foliage. Trailing ivies and evergreen ferns such as Asplenium scolopendrium will also work well with this combination.
Add even more seasonal interest to these autumn/winter containers by underplanting with low-growing dwarf bulbs such as crocus, Eranthis hyemalis, scillas, Anemone blanda, dwarf narcissus and grape hyacinths.
Of course, there are also plants that work best as solitary container-grown specimens, where their singular charms speak for themselves. Topiaried box, bay laurel and bamboo aside (these are ubiquitous for a very good reason), the red tussock grass, Chionochloa rubra, looks glorious when grown in a large pot or container. Beaded with silver raindrops, its quivering copper leaf-blades bring life and light into the garden, even on the wettest and darkest of winter days.
Containers generally look better in a huddle of three contrasting sizes (triangular formation) rather than as solitary specimens. Alternatively, line up an uneven number of identical containers in a formal row – I’ve see this done very successfully using the red-berried, evergreen shrub, Skimmia japonica ssp. reevesiana – while two matching containers will also look great at either side of a doorway, garden gate or flight of steps. Remember that containers can be heavy and difficult to move, so try to place them in their final position before planting. If they do need to be moved, avoid lifting. Instead, place the container on a sheet of strong plastic and then it slide along the ground to its new position.
The right container
Bigger is better, as large containers offer much more scope for interesting plant combinations, are less prone to drying out or blowing over, and also offer greater frost protection to vulnerable root systems. For larger plants, aim for frost-proof containers with a diameter and a planting depth of at least 45cm. If you’re limited to windox boxes, choose only lower-growing plants.
Avoid containers without proper drainage holes (strangely, these can often be seen for sale). Aquatics aside, no plant likes to be up to its waist in sodden cold soil.
Use a good quality, John-Innes based compost. It’s more moisture-retentive while its weight also gives extra ballast. Plant densely. Unlike summer beddng, these plants aren’t going to make new growth over the winter months.
Finally, in severe cold, swaddle with fleece. Avoid letting containers dry out. Just like humans, pot-grown plants appreciate a refreshing drink of water – even in the middle of winter.
We can’t wait until next April, when the tulip/hyacinth portrait of James Joyce that was planted in the National Botanic Gardens last week by Dutch Ambassador Paul Schellekens and school children from Scoil Mobhi, Glasnevin, Dublin and Saint Michael’s National School in Limerick, is expected to come into flower