Sweet lemon verbena, rosemary, bay, and sensitive, ferny acacias have all come through the new-style winters unscathed, and those climbers once thought too tender for the great outdoors . . . delights such as Jasminum polyanthum, Pandora pandorea, grape vines and passion flowers . . . are now clambering to cover sheltered walls all over the capital.

But beware of all this mildness. It's easy to forget just how lethal a hard frost can be when it comes, and when it comes it's sudden and takes you completely by surprise.

The first thing the gardener needs to know about frost is that plants in pots are much more vulnerable to it than those growing in the open ground.

So if you have things in pots that are borderline hardy and you don't want to lose them, then either drag these inside to a frost-free place, or like many of us who garden in cramped urban spaces, wrap your precious plants in swaddling clothes and leave them where they are.

For the best swaddled look, use wraps and blankets made of natural materials, such as straw, withered wild bracken fronds and hessian sacking.

Less beautiful are shopbought horticultural fleeces, but they are highly efficient.

Or you can resort to bubblewrap, old blankets or even horrible plastic drainpipes, for sliding over the stems of smaller banana trees, which should have their leaves cut off first. The banana's snout should also be protected, which is where the bracken fronds come in handy for stuffing them.

Palm trees should have their foliage scooped up and tied in an upright top-knot. If it's very cold, the crown area of the palms will also need to be wrapped. Tree ferns are one of the easiest to protect.

If leaving them in the ground, just stuff the crown with straw, leaves or bracken; fold over the fern's own fronds and secure the whole lot with a porous wrapping such as sacking or chicken wire, porous because the trunk of the tree fern needs to be kept damp and tree ferns only take their moisture, and their nourishment, through their crowns.

Terracotta pots still standing in their saucers should be taken out of them and allowed to drain freely for the rest of the winter. This is because in icy weather, terracotta containers are less likely to crack open if the compost in them is allowed drain properly and there's less water to freeze.

Stand the pots off the ground, which not only assists drainage but helps to deter slugs and other pests, such as the dreaded vine weevil. You can stand them on half bricks, even blocks of wood or, best of all, those shapely sets of terracotta lions' paws or classical scrolls, which come in different sizes to suit different pots.

Buy the book

Dermot O'Neill, author, affable radio and television gardener and editor of the sumptuous Garden Heaven magazine, has always had a palpable passion for roses, the flower of romance.

So it's no surprise that his first book for the specialist English publisher Kyle Cathie . . . the first of a new three-book deal he's agreed to write for them . . . is a glossy, lavishly illustrated and very attractive big hardback all about his favourite flowers.

In Roses Revealed, Dermot takes us by the hand and guides us through a maze of roses, stopping to tell us all about his top 200, selected for their exceptional qualities, including scent, beauty, length of flowering and resistance to disfiguring diseases.

He showcases the right rose for the right place and purpose, be it climbing, rambling, a bush or for ground cover and details his personal experience.

The second part of the book, which has a prestigious introduction by the English rose breeder David Austin, contains a useful, illustrated directory of roses, along with their vital statistics and suitability for a particular purpose.

The last section is immensely practical, with tips on buying, planting, pruning, training, propagating and nurturing your chosen beauties into the future. The finish has a fine glossary and a list of international rose gardens open to the public.

Roses Revealed (right), published by Kyle Cathie, approx 42.95