'It is the spirit of the age," wrote Gore Vidal, "to believe that any fact, no matter how suspect, is superior to any imaginative exercise, no matter how true." So, to fill the short interval before the next pub quiz lurches into your sights, here is a quiverful of facts, loosely attached to gardens.
* Soon after he arrived in Downing Street, the PM announced that he intended to "take practical steps to make sure Government is properly focused on our quality of life as well as economic growth". Unsurprisingly, the Government survey that followed found that highly-paid jobs did not always make people happy. People on relatively low wages (c£31,721) who work in horticulture and agriculture scored high in the happiness stakes, coming third after vicars (£20,568) and chief executives (£117,700).
* There are about 22 million gardens in the UK and though many of them are small (average size is 190sq m/2050sq ft), taken together they cover an area the size of Suffolk. In UK cities, green space takes up from 57 per cent to 64 per cent of the urban area, with gardens accounting for 35 per cent to 47 per cent of the total. That means that, on average, gardens occupy a quarter of all city space. It's because they so often link up with railway embankments or parks that gardens become vital links in urban wildlife corridors.
* As recently as the 1960s, Britain's gardens were being written off (by the Oxford ecologist Charles Elton among others) as "biological deserts". But in a study which continued for 30 years from 1980 onwards, Jennifer Owen recorded 422 species of plants and 2,204 species of insects in her own garden in Leicester. She limited herself to just 34 groups of insect, but estimated that if she had taken on all the known groups, the total would have been closer to 8,450, a third of all insects native to the UK. In her list were 20 insect species that had never before been found in Britain and another four species that were completely new to science. Our gardens are not so much deserts as riots of biodiversity.
* Each year the RHS (Royal Horticultural Society) publishes a list of the pests which have prompted the most queries and complaints from their members. The list for 2014 won't be published until February, but you can expect slugs and snails to feature prominently. In both 2013 and 2012 they were branded as Britain's top garden pest. After slugs and snails last year came vine weevils, capsid bugs, mice and voles, cushion scale, glasshouse red spider mite, glasshouse mealybugs, plum moth, ants and lily beetle. Some pests (slugs and snails, vine weevils, cushion scale, glasshouse mealybugs, ants and lily beetles) are rarely out of the lists. Others, such as the cypress aphid and fuchsia gall mite come and go, often as a consequence of the particular weather conditions that change from one year to the next.
* Garden stuff – flowers, grass and hedge cuttings, leaves, small branches, twigs and weeds – makes up 14 per cent of the average household waste. Around 94 per cent of local councils collect garden waste and take it to composting > sites. After removing stuff that can't be composted, the waste is shredded and laid out in long piles to decompose, usually in the open air. The process is similar to home composting, but because the heaps are so big, they heat up to as much as 60C. This means that enzymes and bacteria work more quickly so that waste can be composted within eight to 16 weeks. Finally, the compost is screened and graded for various end uses: soil improver, mulch, turf dressing, or as a constituent of multipurpose garden compost and topsoil. We all dutifully use this stuff, but is it as fit-for-purpose as peat? No, it's not.
* Britain's gardeners spend an average of £2 billion a year on plants and gardening products. Or at least that's as much as we will admit to. The only bill I can't put out of mind is the one that comes each month from our local garden centre where I have an account. November's bill came to £19.96: One 30-litre bag of John Innes No 3 compost (£4.99), one 100-litre bag of Multipurpose compost (£7.99), a pack of 10 vine eyes (£3.49), a sack of 6mm gravel (£3.49).
That doesn't seem outrageously extravagant and I hang on to the conviction that seeds and plants and garden sundries remain one of the most miraculous bargains that money can buy. Who wants to battle with January sales when they could be cruising peacefully through their local garden centre, dreaming of forget-me-nots (£2.25 for a tray of six) or the possibilities of a clutch of flowering pansies?
The best way to save money in the garden is to make a list of what you want and stick to it. That is true of all shopping, of course. It is one of the reasons that supermarkets are so dangerous. You go in thinking of nothing but a bag of self-raising flour and come out with a jar of lemon-stuffed olives, a carton of apple juice with mango and an oven cleaner which promises (but never delivers) miracles.
But though I may resent my own weak-mindedness when I am wandering the supermarket's aisles, I positively encourage it when I'm among plants in a nursery. Different standards apply. I want to be led astray. I'd be unlikely to scoop up something huge and important, such as a tree, on a whim, but that leaves plenty of room for impulsive manoeuvre among herbaceous perennials and bulbs.
Only this week, I went into the garden centre for some more compost and came out with a delicious little Cyclamen coum (£3.49). Who could resist its rounded leaves, symmetrically marked with silver? Its first magenta bud is already beginning to open. These cyclamen look frail, being only 8-11cm high, but they are survivors, and undemanding. They will motor all season on a handful of bonemeal. I did not need that cyclamen, but it has certainly given me more pleasure than the compost. Come on gardeners. In 2015, let's push that total beyond the £2 billion.
WHAT TO DO
* My mother adored Christmas roses ('Helleborus niger') and grew them very successfully in a shrubbery. But she always protected the blooms with a cloche. If you want picked flowers to last indoors, sear the cut ends of the stems in boiling water for about 20 seconds.
* Plant garlic by splitting a head into separate cloves and pushing them firmly into the soil. Set them about 15cm/6in apart and cover them until they are rooted, to stop them being tweaked out of the soil by birds.
WHAT TO SEE
* A 300-year-old horse-chestnut tree ('Aesculus hippocastanum') on the National Trust's Hughenden estate in Buckinghamshire has been declared the largest horse-chestnut in the country. This veteran tree has a girth of 7.33m/24ft which confirmed its champion tree status on the National Tree Register. For more information about the National Trust's top trees visit nationaltrust.org.uk/toptrees. The park at Hughenden, High Wycombe, Bucks HP14 4LA is open all year, dawn till dusk.