At this time of the year I don't like my greenhouse. It sits lumpenly in the garden, a reproachful figure dressed in grimy, cob-webbed glass: its contents a few depressed plants and the accumulated flotsam and jetsam of last year's growing season. Clearing it out and scrubbing it down is an irksome job, like washing an unco-operative, dirty dog - and I inevitably end up cold and soaked, just as if I'm laundering the hound.
But when it's finally clean, how it shines and sparkles, and invites one to come on in: to sow, to grow, to propagate - and generally to have a helluva good time. It is a secret world (despite its transparent walls) where time is forgotten in the engrossing business of handling seed and compost, in taking cuttings, in potting on and pricking out, in watering and hosing down, and in doing the hundreds of repetitive tasks that lend a narcotic rhythm to gardening.
In the greenhouse, the spring sun's weak rays are magnified into soothing heat therapy, excellent for dicky backs and damp bones. In the greenhouse, the gardener is governor, with godlike power over water, air, food and light. In the greenhouse, you can have food for nine, 10, even 11 months of the year.
But enough of the purple prose, and on to the practicalities. If you don't have a greenhouse, but yearn for one, where do you start? My advice is: start big. You know when you're buying clothes for children, you never buy their size, you always buy the next one up? Well, the same rule applies to greenhouses. Think of the biggest one you could possibly need, then add another 10 per cent onto the price and get a size larger. That will keep you happy for a year or two.
In Ireland, the choice in new greenhouses seems limited to aluminium-framed structures: they're not pretty, but some are now available painted green - an expensive, but more acceptable alternative to the cold, industrial look. The best-seller is a basic, unpainted, six by eight foot version (around £275, plus about £200 for installation, which I recommend, unless you are a seasoned DIY person). Most small glasshouses come with one or two opening roof windows. You need two, and preferably two side windows also, for enough airflow to cut down on sweltering heat and to prevent the fungal diseases that thrive in a sluggish atmosphere.
Other essentials include a maximum-minimum thermometer to keep track of night-time lows and daytime highs. Digital thermometers are certainly very swanky looking; I've had three and they've all become wildly erratic in colder weather. Now I rely on an old-fashioned mercury type. Shading the greenhouse is necessary in all but the gloomiest of summers. Either use "Coolglass", (about £3.50 for a package) which you mix with water and paint on, or special shading material (or old net curtains, if you're economically-minded). Obviously, a water source nearby is important. In summer you must water plants and hose the floor (this is called "damping down") once or twice a day to bring down the temperature and to raise humidity.
But what to grow? If you like a challenge, then alpines, ferns, orchids or tender ornamentals (for which you need artificial heat) may beckon, but for guaranteed, gratifying success, simpler stuff is in order. Food is the thing. Tomatoes (a warm, heavily-ripe, home-grown tomato is an entirely different fruit from the anaemic, supermarket sphere), chillies, sweet peppers, courgettes, cucumbers, aubergines and salad leaves.
In my now-too-small glasshouse, these cram into the soil-bed and onto the greenhouse bench from May onwards. When I'm on the ball, all - except for the chillies and salad leaves - are fed weekly with an organic plant food, either home-made (from nettles, comfrey or manure) or with a commercial preparation. But before these take over there is room for hundreds of seedlings: hardy and half-hardy annuals (the latter germinated in the warmth of my kitchen) and vegetables, some to grow on under glass, others to be planted out in the garden later on. And there's always space for cuttings, in the shadier regions under the greenhouse bench.
Slugs and snails can be a menace, but I kill them off by luring them into containers of extremely cheap beer sunk into the soil-bed. Whitefly, little floaty creatures that congregate on the undersides of leaves, are a common greenhouse pest. Every year I grow French marigolds to ward them off, and last year, when I had only a couple of meagre plants, I found my first whitefly in seven years.
Greenhouse gardening is time-consuming and finicky, it's high maintenance and often expensive (stop thinking right now that you're going to save money on the food you grow!). But inside those four, intoxicating glass walls, the outside world rolls away - and nothing else exists but gardener and plants.
Suppliers of greenhouses and accessories: Lenehans, Capel Street, Dublin 1; tel: 018730466. Website: www.lenehans.ie. Most garden centres carry greenhouse equipment; Woodies DIY shops also have a good range.
Greenhouse manual: The Greenhouse Expert by Dr D.G. Hessayon (£6.99), published by Expert Books; available from book shops and garden centres.
Jane Powers can be contacted at: jpowers@irish-times.ie