Isn't there a warning that Aslan gives to the Narnians to protect the tree? I always imagined that the tree was well taken care of for several centuries, but as time wore on, the decreasingly careful Narnians forgot about and neglected the tree until it died.

I suppose you're thinking of this (my emphasis):

"Son of Adam," said Aslan, "you have sown well. And you, Narnians, let it be your first care to guard this Tree, for it is your Shield. The Witch of whom I told you has fled far away into the North of the world; she will live on there, growing stronger in dark Magic. But while that Tree flourishes she will never come down into Narnia. She dare not come within a hundred miles of the Tree, for its smell, which is joy and life and health to you, is death and horror and despair to her."

Perhaps it might have lasted even longer if they had guarded it longer. It wouldn't have lasted forever, but there was enough magic in it to last far longer than an ordinary tree. It may have flourished for eight or nine hundred years - Lewis doesn't give us any details, not even in the timeline - but those are the numbers we might get from the timeline.

Actually, according to the official timeline LWW takes place in the year 1000 Narnia time, and we know she ruled the land for 100 years, so that would indicate that she conquered Narnia in the year 900. The longest living varieties of apple trees live 100 years or more, so 900 years is plenty of time for it to die of old age.

While reading this topic I had an interesting thought.

Perhaps the tree played some part in Jadis’ decision to freeze Narnia in winter. It is probably unlikely that the Narnians would be able to grow such a tree again, but perhaps Jadis did not want to risk this and froze the land to prevent them from making any such attempt.

^That's actually a good point, she probably would take precautions to make sure no one brought another apple from the garden.

Another thought: why did Jadis stop at ruling only the (geographically small) country of Narnia? In her own world, she wanted to rule the whole of it, not just the city or country of Charn, and destroyed every other living thing when it became apparent that there was no other way to achieve her ambition. In our world, she expected to be made ruler of the whole of it. So why did she not take over Archenland, Calormen, Telmar, Harfang...?

Another thought: why did Jadis stop at ruling only the (geographically small) country of Narnia? In her own world, she wanted to rule the whole of it, not just the city or country of Charn, and destroyed every other living thing when it became apparent that there was no other way to achieve her ambition. In our world, she expected to be made ruler of the whole of it. So why did she not take over Archenland, Calormen, Telmar, Harfang...?

Maybe she planned to, eventually. But Narnia was her first priority. I think a lot of her motivations rested not only in the desire for power, but a hatred toward Aslan. And Narnia is a country that has always been tied to Aslan much more than the other countries.

I have to wonder, though, if the Winter she instigated didn't affect those other countries as well.

~Riella

Apparently Jadis' winter didn't affect either Calormen or Archenland directly. Cor and Corin were born the year that the Tisroc came to power in Calormen, which was the year that the White Witch was destroyed. Arsheesh was telling Anradin about it at the beginning of HHB, and how he had rescued the baby. The Witch's snow seems to have stopped at the mountains of the south which separated Archenland from Narnia. Though, I bet her winter went far west, as far as Telmar, wherever it was. It is significant that there seems to have been a link between the Lamp post Jadis planted in Lantern Waste and the wardrobe through which the Pevensies reached Narnia.

There was further discussion about the White Witch at the conference the Tisroc had with Rabadash and Ahoshta (with Aravis & Lazaraleen listening in behind the sofa). The Tisroc seems to have left Narnia well alone to stay away from the White Witch. The White Witch attracting all the rain/snow further north would have caused a rain shadow, hence the desert separating Archenland and Calormen. Archenland, though suspicious of Calormen seems to have stayed on the southern slopes of the mountains separating it from Narnia, out of range of the WW, maybe.