Just copy the html code from the image links to the right of the photo in your photobucket album- some folks have no time to be clicking all around.

It looks plain burnt up to me.
If you overwinter indoors you need to slowly acclimate them back to full sun once it warms up, not just stick them out in blazing sun.
But then I know nothing about macadamia nut trees despite living in the tropics for 30 years.
Hopefully someone will come along that can truly help you- I just mainly wanted to tell you how to properly post a photo when asking for help.

Good luck..

It's so true about moving plants from shade into sun too quickly. It burns them to a frazzle. But I think your plant looks like it's over watered or has poor drainage. They're not actually a tropical plant, they come from a warm temperate (or sub tropical) climate. They grow generally in hilly country where they get good drainage and it can get quite cool.

Haha sorry I didn't realize that was okay to do, I was just following the format of some other posts i've seen! I suspected I had sent it out too quickly. I hope it can still recover, I'd hate for it to die on me...it wasn't cheap! As far as watering and drainage, I mixed about 30% of sand into the dirt to aid with drainage, and it only gets watered (when indoors) about once a week with maybe a few cups of water. I'm thinking about changing the pot to something a little sturdier (the plastic is drying out) so when I do that I'll be sure to add a bit of gravel to help with the drainage.

If it did get too much sun suddenly it's the new leaves that would burn the quickest. Old leaves would cope better but could still get damaged.

I have one in the ground that has to be moved. The soil is very poor and drainage is bad. Trouble is it's going to be a major job to do it.

Well even the newest leaves are about 8 months old, but yea those seem to be the ones that burned the worst. I'm going to set it up with a little lamp to try and ease it in this time. I just noticed today that one of the branches is starting to sprout new leaves so that's a good sign. Moving it might not be as big of a job as you might think, I've seen machines that are specifically designed to pick up a tree and safely transplant it somewhere else. Perhaps you could look into renting something like that for a couple hours. As far as your drainage goes, what kind of soil do you have in your area?

New leaves are a good sign. Acclimatising slowly for sun is the way to go.

Soil varies a lot across my place, this area is notorious for that. Where the Macadamia is it's a sort of lateritic gravel overlaying a fine type of "clay-like" soil. The "clay" doesn't retain water except during the wet season, really a matter of the water table being high. During the dry season it sets like concrete.

The tree's about 3 metres tall, so not big. But it's in an awkward position. What I'm planning is using my tractor. I have a couple of augers (post hole drillers) and can drill a series of holes around the tree. After joining up the holes I can wrap the soil/root mass and lift the lot out. That's the theory, anyway. But I need to prepare where it's going to go.

Just NW of Boston here. When I was in HI in Feb 2010 my daughter and I took home some macadamia nuts we found. I had an apt in Philly at the time. Long story short one sprouted and took hold, has been growing steady since. I observe that it likes increasing pot size, that it does not like to be suddenly set out in blazing summer.

It will be 4 in April. Has anyone with an indoor/outdoor Macadamia gotten nuts? The picture above shows the crown growth caused by a mid-August pot size increase.

Here is a link that might be useful: Picture before recent repot