THE REAL CHRISTMAS TREE: HOW TO CHOOSE ONE THAT LASTS FOR YEARS

The fir you buy in December was cut back in October. That explains almost everything that happens next: it drops its needles within ten days, it hardly smells of anything, and by the 7th of January it is out by the bins.

Cut or alive: the difference you cannot see in the shop

A cut fir is a large branch in a stand. It has no roots, it does not drink, and it has been dying since the day it was felled. It lasts as long as it lasts.

A living fir arrives with its root ball or in a pot. It has roots, it drinks, and if you treat it properly it leaves the house in January exactly as it came in. Next year it is the same tree, a little taller.

In the shop the two look alike. The difference is at the bottom: look for soil and roots. If the trunk ends in a clean cut resting on a cross stand, it has been felled.

Which species to choose

Abies nordmanniana. The Caucasian fir is the Christmas tree of choice for one very specific reason: it holds its needles. Dark, glossy, soft foliage, one of the few that does not prick you while you hang the decorations. If you are only going to have one, this is it.

Picea abies. The Norway spruce, the European classic. It smells far stronger than the nordmanniana, and that is its charm: it is the scent people remember from childhood. In return it pricks, and it sheds sooner in a dry house.

Picea pungens glauca. The blue spruce. The most decorative of them all thanks to a blue-grey no other tree has, and after Christmas it makes a beautiful garden tree.

Abies pinsapo. The Spanish fir comes from the mountains of Cádiz and Málaga, and it copes with heat far better than the northern species. If you live somewhere Mediterranean and plan to plant it out later, it is the sensible bet.

The weeks it spends indoors

This is where the tree is won or lost, and hardly anyone allows for it: a fir in December is going into dormancy. Putting it in a living room at 22 degrees wakes it up all at once, and it pays for that.

Bring it in as late as you can. Ten days to a fortnight indoors is reasonable. A whole month is asking a lot of it.

Away from radiators and the fire. Dry, direct heat dehydrates it within days. The best spot in the house is the coolest one, not the grandest.

A little water, often. The root ball must never dry out, but it must not sit in water either. A glass every couple of days and a saucer underneath is enough.

LED lights. Old-style bulbs give off heat, and they give it off right where the foliage is.

And after Christmas

The classic mistake is to take it straight from the living room out into a frozen garden on the 7th of January. Heat to cold in one step, and it scorches: the foliage turns brown within a week.

Do it in two stages. A week somewhere in between, a porch, a conservatory or a cool outbuilding, and then outside. It is a two-minute decision that determines whether the tree reaches next Christmas.

If it is staying in a pot, move it up a size every couple of years, with good drainage and a compost that does not pack down. If you are planting it in the garden, do it the following autumn rather than in January: we explain why in what to plant in autumn and when.

The mistake that kills it

Keeping the saucer permanently full of water. A fir wants damp soil, not wet, and waterlogged roots rot without anything showing above ground until it is too late.

If you take away one thing: keep it cool, keep the soil damp, and keep it indoors briefly. Do that and a living fir lasts for years.

And if the fir is staying out in the garden these weeks, have a look at what to do before the first frost.