There is only one rule on the coast at any time of year – never, ever take it for granted. It's easy to pity those in landlocked countries, but many people in the UK have never had the chance to visit the coast. Imagine never having tasted that salt air, never hearing that soothing swoosh.

That 'annoying' seagull is the sound of the British coast, more than that endless, sparkling, lead-blue-green-white water itself. Spring is the perfect time to be here – and this is why:

Gorse

It's likely you'll get caught out on a wet clifftop walk in the spring amongst pesky, spiky shrubby gorse. Don't despair, the sun will come out soon enough bringing out the coconutty goodness of this common coastal plant.

The flowers of Ulex europaea last most of the year – catch a glimpse of the yellow, close your eyes and remember cocktails and beaches. This is your reward for heading out on the dreariest spring morning.

Dolphins

Bottlenose dolphins only seem to live on the TV or in Florida, but we have a large resident pod in west Wales. These cetaceans are also record breakers in their own right: having both a larger than usual size and more than 900 different vocalizations compared with the usual 300.

Coastal birds

Some birds are getting ready to leave – geese fuss and chatter on saltmarshes, while fieldfares gather on coastal fields. Other birds begin to arrive from the south – swooping swallows and awesome ospreys will start arriving soon. The first skylarks’ singing is always a magical sound, essentially yelling that summer is soon on its way.

Terns fly gracefully like little angels, bringing late memories of winter with their pure white feathers. Some, such as Arctic terns, have come from the Antarctic which explains why they don't arrive until May. The coast is a great place to see birds refuelling following some epic journeys from the south, or ducks and geese heading north-east to Siberia.

Oil beetles

It is nice to look at the sea, of course. It's the shifting, shining focus whenever we walk on coastal footpaths, but in the spring I'm often looking on the path for a large black creature hauling itself slowly across the ground. It's an oil beetle, incredibly rare but the coast is their home, and if you look you might find them on sandy paths emerging from their winter nest.

They didn't make this nest themselves, an individual with a gravid, swollen abdomen means she's heading to a solitary bee nest to burrow in and lay her eggs. The young, called 'triangulins', crawl up a grass stem and wait to hitch a ride on these bees. Once back at the nest, they eat her eggs.

Coastal butterflies

On a calm day, coastal grasslands are the perfect place to look out for that summer herald, the butterfly. Some beautiful ones are properly coastal too, if only they were named appropriately: the common blue is neither just ‘common’ nor just 'blue'. It's bluer than the sky it floats under, bluer than the sea it flies near.

A glowing terracotta mosaic is a 'wall', the mottled stone suddenly sprouting orange glowing eyes and rising up it is a 'grayling' – they were really having an off day when naming these coastal marvels. Dark green fritillary – that's more like it: big, green and whizzing past on a mission, almost too floaty a name for the speed demon of the lepidopteran world.

Hawthorn

The buds of this spiky little tree are an early but sure sign spring is on the way, whilst many months later their pure white froths of blossom hint the segue to summer. The coastal ones often have truly wonderful appearances and can also be very old, twisting as the winds whip them into fantastical structures over many years.

In a morning walk to the beach the shapes can be dolphins leaping, waves curling, the wind in a lover's hair. In the evening, tired minds may see those shadowy forms beady, starry-eyed eyed crows, cackling witches or brooms as the first bats emerge from their winter torpor.

Jellyfish and the like

Late spring is jellyfish time – ready to go with your summer ice cream – however the vast majority don't sting badly. Jellyfish are rather beautiful in an alien sort of way, helped in this supernatural quality by the fact they tend to arrive in a huge bloom overnight.

Often, warm Atlantic currents have brought them and they are more levitators than swimmers, unable to fight the tide. It's worth looking out for leatherback turtles following these jellyfish too. Ones to avoid: floating translucent pillows (Portuguese Man-o-War), ones with red arrows in them (compass jellyfish) and a giant orangey blob (lion's mane jellyfish).

Coastal flowers

The flower-rich grasslands on clifftops and dunes are as spectacular as a wildflower meadow – sometimes you have to get down and look closely, while in dunes we have some true show-stoppers. Violaceus spring squill and coral pink thrift can form a swathe of colour in short clifftop turf.

In springtime dunes, whitlow grass shines like a diamond, with pearl-like flowers. Then orchids – showy pinkish early purples appear soonest, ready for the bigger show. Later it is the turn of saurian green and pink lizard orchids, frothy purple early-marsh orchids, vermillion and chalk marsh helleborines. A special mention must go to the delicate mauve golfballs of field scabious.

Nesting birds

One of the best early spring sights is herons nesting in tops of trees – and where better in coastal valleys, where you can look down into the tops of the trees before the leaves start to cover them over.

Here you can get almost eye to eye with these reptilian, lanky creatures seemingly clinging to the treetops for dear life. Rooks fly by with sticks in their beaks. On the cliffs, a scope helps you see the pointed eggs of guillemots and spot other seabirds, starting to gather in their colonies in March.

Reptiles

The coast is one of the few places warm enough and wildlife friendly enough to support our reptiles. What could be more of an indicator of coming warmth than a cold blooded creature spotted out and about? As the sun lengthens the days and warms the ground, adders emerge from their hibernacula more frequently and can be spotted sunning themselves in coastal heaths and scrub. Slow worms slither through the bracken, while grass snakes (our largest snakes) bask near ditches.

Gwen Potter is the National Trust Ranger for South and West Wales, Coast & Countryside.

The National Trust is celebrating its 50th anniversary of the Neptune Coastline Campaign - the Trust now manages 742 miles of coastline in England, Wales and Northern Ireland, with some real natural history treasures on the coast.

How many of these have you seen? Let us know and join in the conversation using #SignsofSpring on Twitter, Facebook and Instagram.