Alan Titchmarsh has always loved coastal gardens, but it wasn't until he ended up with his own a few years ago that he truly appreciated the possibilities.

Gardens by the sea have always fascinated me, no doubt because they signal a break from the daily routine. As a child, a trip to the coast often meant that it was holiday time and, for me, that feeling of release has continued into adulthood.

The tapestry of memories includes visions of a sea of hydrangeas in Sussex and, later, a tumbling mass of them among a forest of gunnera in a ravine at Trebah, Cornwall.

Wildflowers of the Penwith peninsula are particularly special – sea pinks and bladder campion, foxgloves and the magenta spires of Gladiolus byzantinus – as is the wonderful garden crammed with succulents and subtropical beauties that has developed above the clifftop theatre of Minack in Porthcurno.

From there, it’s only a stone’s throw (well, a helicopter flight or a passage on the Scillonian III) to that magical island of Tresco, where tender plants shoulder each other out of the way to create a gardener’s paradise.

The fact that the sea stabilises temperatures – frequently preventing them from plummeting as they do inland on clear, frosty nights – means that mari-time gardeners can grow a larger range of plants than their landlocked counterparts.

All of this was of purely academic interest until I acquired a garden on the north coast of the Isle of Wight almost five years ago. I wasn’t optimistic – a north-facing slope on slipper clay isn’t the most propitious of sites for any garden – but I’ve been proved wrong.

Ventnor, on the Isle of Wight, is famous for its gardens by the sea

I’ve managed to grow every-thing from towering echiums to mounds of aeoniums, prostanthera, correa, feijoa and beschorneria, bringing them all safely through the winter without any additional protection outdoors, thanks to the incorporation of masses of organic matter and even greater quantities of sharp grit.

There have been failures: I’m still mourning the loss of a three-year-old Leucadendron argenteum last winter, but console myself with the fact that temp-eratures were unusually low and that, if I plant a replacement now, it might be another 10 years before such depths are plumbed again. Like most gardeners, I’m eternally optimistic.

Of the plants that do well, I especially enjoy the profligacy of Erigeron karvinskyanus – the little daisy that’s never out of flower from spring to autumn and which pushes up happily through my shingle paths.

Callistemons and grevilleas (especially Grevillea Canberra Gem) are a real delight and I find myself planting more and more of them because of the elegance of their needle-like foliage and their willingness to bloom reliably, even early in the year.

Euryops pectinatus studs itself generously with clear yellow daisies for months on end, pushing out from underneath the verandah of our clapboard house like a ray of sunshine emerging from the depths. Trimmed annually with shears after its first flush of flowers, it bounces back unperturbed.

Then, there are the umbels of sky-blue agapanthus, the plum-purple leaves of shrubby dodonaea, towering prehistoric-looking fountains of castor-oil leafed Tetrapanax papyrifer Rex and umpteen tender treasures that I couldn’t risk in my inland Hampshire garden.

Providing an adequate windbreak is by far the most important consideration when making a coastal garden. Salt-laden winds are a real killer, turning foliage black overnight in severe cases.

On the island, we’re blessed with protection from that sturdy coastal stalwart Cupressus macrocarpa, together with ash trees and the tough, but frequently disparaged sycamore. We trim the deciduous trees annually – pollarding the branches, not only to keep them in check and reduce the shade they cast, but also to allow our neighbours a view of the sea.

Moonlight and boats at the beach at the cottage, Shanklin

Any plants that dislike heavy soil (and there are many) are planted on mounds of gritty earth that lift them above the mire, but still allow them access to a moisture supply in times of drought.

Because we don’t spend all our time there (although we are in residence at least once a fortnight), I have invested in an irrigation system that’s operated automatically via small computers fitted to the garden taps. It’s been a lifesaver for the plants themselves and a great solace to me, because my charges don’t wither and turn crisp in the first sunny spell of spring. I would recommend such a system to anyone who has to be away for more than a week at a time.

I marvel at the fact that, even after all these years, the fascination and sheer joy of gardening by the sea is as keen now as it ever was – perhaps even more so now that I have the chance to experiment for myself.

I commend the exercise to anyone with an innate love of plants and a desire to grow those that are generally regarded as too tender for our cool, temperate climate. It will astonish you just what you can grow – and grow well – in a garden by the sea.