Weather is a weird thing. April is notoriously changeable, of course, but still... We went to visit family in Germany over the recent holidays. Calling my parents ahead on Easter Monday, I was told: "We've had 24 hours of snowfall yesterday, there are 30 - 35 cm of snow on the ground. But I don't think you'll need to pack woollen hats and gloves. In any case I have some spare ones." Okay, but jumpers and our coats were a must.

Being someone who prefers to pack rather a bit too much than too little in order to be prepared for all eventualities, I pondered whether to take short-sleeved T-shirts? It was unlikely to stay frosty for long, but we were only at the start of April. In the end, I decided to bring one for each of us: we could always layer it underneath something warmer.

Arriving the next day, we had a snow fight though thawing had reduced the cover considerably. Then the day after, temperatures went up to 20 degrees Celsius - and stayed there for the rest of the holidays, rising even further to 25 degrees a few days later. Obviously, the jumpers and coats did not get so much as a side-way glance, but the T-shirts were washed regularly at night. It's the first time I've been so completely caught out, longing for some shorts, dresses or light-weight trousers and some open shoes. It drove home to me just how drastically the continental weather can change, how quickly it swings from winter to summer - and how much plants there have to cope with.

 Here in Britain you do have temperature swings, too, but rarely that abrupt. Mostly it hoovers around a mean temperature, deviating either side of course, but not in such a topsy-turvy way. Or so I thought. For while I write this, we've just had the hottest April Day in Britain in almost 70 years according to the news, reaching 29.1 degrees Celsius in inner London. And that after what was described to us as a chilly, wet and generally miserable Easter school break. Reports must be true because while I had worried for my plants in pots which dry out quickly when the sun is out and temperatures soar, left alone after a good soaking these were still moist enough at my return a week later to delay watering again and tend to the inevitable mountain of laundry first!

Four days on, it feels like the height of summer. The birds are going mad by the sound of it, butterflies seem to materialize out of blue air (I was going to say “thin air” but this deep forget-me-not blue sky cannot be called “thin” by any stretch of the imagination). Plants seem to explode. The dam is broken and a flood of green surges everywhere you cast your eye. All that energy, delayed and held back in bud, penned up so long out of chilly necessity by the unusually long wintery weather, has burst forth and you can almost literally watch them grow by the hour.  Where there was bare ground two days ago now is carpeted in green.

After daffodils, hyacinths and other spring flowers literally lasted for months, cherry blossom, magnolias and many tulips now have come and either already are gone or are in that blowsy state that indicates they'll be past it in a matter of days, if not hours, rather than weeks. The horse chestnut trees, a few days ago still mostly in that felt-like silver-beige of unfurling new shoots and only showing hints of green, are in full leaf cover, their candles fully-grown with the first flowers already open. It's incredible, surprising me anew every year no matter how many times I've witnessed it before. It could be late May.

I’ve often wondered: if it remained chilly until even later in the year – would plants still hold back? Or would there come a point where it was impossible to contain new growth in buds? Just as you can hold back from going to the toilet only for so long before you “burst”. Not the most appealing metaphor, of course, especially since, unlike any such accident, fresh young green is such a welcome, uplifting sight. But you get the point. And for the plant it might have more drastic consequences than “embarrassment”. Any return of frost could kill the new growth.

This happens, of course, much to any gardener’s chagrin in many a spring when a late frost destroys your hope of blossom or a good fruit crop or sees off your plants altogether if you were too optimistic and planted out too early. But these late frosts are “accidents”, so to speak. A plant tricked into growth by a previous period of favourable weather and conditions could not have “anticipated” this turn of events. And very rarely will these kill the entire plant. They might see off the first shoots or this year’s blossom but most perennial plants (including the woody ones) will eventually recover and continue to live. And annuals will only germinate once the soil temperature has risen to a certain level and stayed there for considerable time. No, if these late frosts really kill a plant, it’s usually your fault for planting out too early and/ or not protecting them.

But what if, like this year, it remained chilly throughout? And not just into late March and April but into June, say? Would trees and shrubs remain more or less bare until then? Would bulbs and perennials - safe those of early spring - hold back below ground? Or would their natural annual rhythm dictate that at some point, when it is perhaps past their normal flowering time already, they have to burst forth? While you could argue that such chilly “spring” would be like keeping plants in a fridge, the rise of the sun to a higher position in the sky and increased light levels would differ from fridge conditions, even if its warmth were not felt on the ground. Well - I guess this is a theoretical question, of no practical merit.