Where they are hardy outdoors, they can get 30-40 metres or more tall (to 60 metres in the wild).

Resin

I'd love to keep it indoors, a rare evergreen(conifer?) indoors.

Resin

And wouldn't an inside Norfolk island need some regular "exercise" to build up the trunk to grow very tall, since there is no wind inside? If I understood you correctly.

Do you think with global warming in Britain
say in 10 to 15 years time that they will
grow outside thats what a few people think.

Yep, "exercise" could be a problem; some places have big fans installed to make it windy to stimulate trunk thickening. DOn't know if Eden does or not.

Resin

So...here is a link to see the Eden Project in Cornwall.

WOW

The ideal indoor climate (aside from doctors' offices and corporate lobbies) is cool and bright; daytime temps ranging from 60-70 F and slightly cooler at night. Norfolk Island pines will adapt to bright indirect light, but will look its best with a couple of hours of direct sunlight daily. If the light source is coming from just one direction, give it a quarter turn weekly to keep it from tilting toward one side.

When the plant is actively growing, feed it with a fertilizer formulated for indoor foliage plants. It is not unusual for the plant to be in a period of rest during the winter months, at which time there is no need to fertilize.

Water the plant when the top inch or so of the soil in the pot feels dry. Use enough water to allow a little excess to escape through the bottom drainage holes. Discard remaining drained water after about 15 minutes.

Biggest challenge is providing the high relative humidity it needs. Norfolk Island pine thrives at 50 percent relative humidity.

It is not unusual for a few needles on the lowest branches to turn brown and drop. If this happens slowly over time, it's likely just normal aging of the branches or possibly from lower light availability. However, if many needles are browning, or if the problem appears more widely distributed among the branches, look to problems of either too much or too little water or too little relative humidity.

I've had one for about 6 years now that was originally a Christmas party favor and it's stayed a very manageable size.

I will know that my zone (5/6) is far to cold to have a Norfolk Pine outside.

Anyway, for the fun of it I planted one outside 3 years ago. A few months later the night temperature hit -3C (~ +27F) and the next morning my tree was gone.

Normally a conifer which gets it too cold just turns brown in a couple of days or weeks, but this was more like what happens to lettuce if it gets too cold.

The tree was a young one, my guess is 3-7 years, approx 60cm high and hadn't really developed wooden cells yet or only to a small extent. After the light freeze is was transformed to a brownish black blob lying on the ground.

It was just like the cullular structure of the tree was completely destroyed - the tree was siply not a tree anymore. Not even a dead tree.

For other plants we see it every year of course, at least for the parts above ground, but I've never before seeen it for a tree.

/Hans Olav

I live in a dorm and I have 15 other potted plants in here. Space is about 150 square feet. No idea what the relative humidity is in here, but it's probably fairly high. High enough, in any case, that my windows get massive amounts of condensation on them.

Still, it didn't suffer too much when I was home this summer and I had to keep it indoors, because it didn't tolerate being outside at all. I'm not sure why, but it never really could get acclimated to the higher sun and heat, and it's still got some noticably sunburnt patches on it (nd the heat was making it constantly wilt.

"The Mall of America has dozens of planted Norfolk Island Pines in their indoor amusement park."

Oh wow. Now I want to go back there. Or find pictures.