Start with what is already there

A seasonal nature diary asks very little of you. You do not need a hide, binoculars or a long walk. You need a notebook that fits in a coat pocket, a pen that works in the damp, and roughly five minutes a week. That is genuinely enough to begin, and it is often enough to keep going for years.

The trick is to lower your expectations on day one. This is not a wildlife survey and nobody will mark it. Scribbled notes, half-remembered bird names and a rough guess at the temperature are all perfectly acceptable. The point is repetition, not perfection — the same patch, the same handful of questions, week after week, until the year starts to show you its seams.

What to record each week

Keep your entries short and use the same headings every time. A predictable structure makes the notebook quick to write in and, later, quick to read back. Most people find the following covers almost everything worth knowing:

• Date and time, plus where you were — the back garden, the same field gate, the lane on the school run.
• Weather: temperature, wind direction, cloud, whether the ground is wet, frosty or bone dry. A simple word or two will do.
• Plants: buds swelling, first leaf, first flower, berries colouring, leaves turning or falling.
• Birds and animals: what you saw, what you heard, and what was noticeably absent.
• Small shifts: the first wasp of the year, frogspawn in the pond, a hedgehog snuffling under the bird feeder, the smell of rain on dry earth.

Weather is worth more attention than people expect. A note of wind direction on a cold morning tells you why the rooks were feeding in the far field rather than the near one. After a few months, those offhand remarks start to explain each other.

Firsts and lasts are the backbone

If you only ever record one thing, make it the year's firsts and lasts. These are the entries that turn a diary into something you can actually compare, year on year.

Note the first swift screaming over the rooftops in late April or early May, and the last one leaving in August. The first swallow, the first chiffchaff singing, the first redwing arriving from the north in autumn. The first hawthorn blossom, the first elderflower, the first ripe blackberry, the first sloe dark enough to pick. The first ground frost of autumn and the last one of spring.

Write the date plainly, without padding. "First frost — 14 October, grass white, car windscreen needed scraping" is worth more than a paragraph of reflection. Those single lines, gathered over three or four years, quietly tell you what your corner of the country is doing.

Build a rhythm that survives bad weather

The diary will fail if it depends on a leisurely wander. Tie it to something you already do. A Sunday morning mug of tea at the kitchen window is ideal — you can watch the feeders, judge the sky and write two lines before the tea goes cold.

It helps to keep the notebook and pen in one place: on the windowsill, in the coat pocket by the back door, beside the kettle. If you have to hunt for it, you will not use it. A pencil is kinder than a pen in cold weather, and a cheap notebook is better than a beautiful one you are afraid to spoil.

Short entries matter more than long ones. A single line written every week for a year beats three pages written in a burst in May and nothing afterwards. If you miss a fortnight, simply note that you missed it and carry on.

Reading back: where the patterns appear

After a full year, sit down with a cup of something warm and read the whole thing through. This is the reward, and it is surprisingly absorbing. You will find that your patch has a rhythm you had never consciously noticed: the fortnight when the rooks gather, the week the ash comes into leaf, the point in late winter when the birdsong suddenly thickens.

By the second or third year, comparisons become possible. Did the oak leaf earlier or later than last spring? Did the fieldfares stay longer? Was there a proper cold snap in January, or did the hellebores flower straight through it? You will also start to notice how much of what happens is ordinary and repeated, which is oddly comforting in itself.

And you will notice your own entries changing. The early ones are hesitant; the later ones use proper names and describe the light. Observation is a skill, and it sharpens simply through use.

Small comforts, gently accumulated

There is a quiet pleasure in a practice this modest. It gives shape to a wet Tuesday. It turns a routine walk into something with a purpose that costs nothing and demands nothing. And it encourages the sort of seasonal home comforts that make a British year bearable — the blanket that comes out when the first frost is logged, the lamp lit earlier, the soup pan back on the hob.

You are not trying to become an expert. You are learning the particular weather and wildlife of one small place, in your own handwriting, one line at a time. That is a gentle and thoroughly worthwhile way to spend a year — and then another one after that.