You DON’T have to put bananas in pyjamas...
...but keep the horticultural fleece handy – just in case a prolonged cold snap strikes
This time last year I played Russian roulette with my banana plants. Instead of wrapping them up in fleece for winter, I decided to let them fend for themselves. It was the first time in two decades of growing these leafy lovelies that I hadn’t prepared them for colder weather, and I spent the next four months biting my nails every time a frost was forecast.
Fortunately the weather was mild and the plants remained unscathed. However, had there had been a prolonged cold snap, my grove of nine, three-metre-tall bananas would have been hit hard. Well I don’t want to spend another winter worrying about their plight, so I’ll devote a few hours to insulating them this week.
Bananas are not the only plants that benefit from protection against strong winds, heavy rain, frost, hail, snow and whatever else winter has in store. Palms, cordylines, tree ferns, delicate shrubs and many other architectural gems are best given some attention, along with agapanthus, dahlias and similar late-flowering, tender bulbs.
Some of these plants need a sheet of horticultural fleece throwing over their branches or a thick blanket of mulch to shield their roots from ground-penetrating frosts. Others may need something more substantial to keep them from harm, such as a cage-like structure filled with insulating material.
The stems of my Japanese banana (Musa basjoo) can tolerate down to 0C for brief periods, but die back when the mercury plummets any further. Most will regrow from the base in spring as the roots are hardy to about -15C. However, if you want to retain the current height of plants, then you must protect everything above the ground.
Keep individual plants snug by removing leaves until you have a clear stem. Next, wrap from top to bottom with horticultural fleece, ensuring the plant is fully covered. Fasten with twine and wrap again, this time using hessian. Remove the material in mid spring, or when there’s no longer any frost.
A group of bananas close together can be surrounded by a ring of chicken wire secured by cable ties. Fill the void with straw, and if necessary add another storey of chicken wire until the structure is a tad taller than the highest stem. After cutting off leaves, stretch a waterproof sheet over the top to stop stems rotting from the wet.
There are various ways to brace tree ferns for winter. In mild places, all you need to do is stuff a handful of straw into the crown (hollow at the top of the trunk) to protect embryonic fronds. Another option is to wrap a piece of fleece around the very top of the trunk a few times, making sure that some of the material runs across its crown.
Chusan palm (Trachycarpus fortunei), Chamaerops humilis and many other palms can endure temperatures as low as -10C, but I’d still recommend boosting their tolerance by stuffing straw into the growing point of plants. Hold in place with twine to prevent it being blown out in windy conditions.
One palm that needs closer attention is Canary Island date palm (Phoenix canariensis). Mature specimens are hardy down to -8C, but the younger ones will need protec
tion — pile straw around the base, tie leaves together and wrap the entire thing with fleece.
Cordylines are popular, palm-like plants that will suffer badly from both prolonged frosts and dieback caused by rainwater.
Winterproof them by gathering the leaves vertically and binding together with twine. Finish by wrapping the entire plant with horticultural fleece.
Some evergreen shrubs from warmer parts of the world have foliage that’s easily blackened by frost or freezing gusts. Prevent damage by slipping a fleece ‘jacket’ over the top and closing it tight at the base. Remember to remove it once the weather improves so more light and air can reach the plant.
If you have heavy soil or live in a cold place, summer-flowering bulbs will need lifting, drying and storing in a frost-free place. Those in milder parts, or with welldrained ground, can be left in situ, covered with a 15cm layer of organic material.
Move specimens in pots to a greenhouse, front porch or conservatory and water them sparingly.