Hi - yet another dwarf lemon tree leaf drop question, I'm afraid. I have looked through many, many posts about leaf drop, but still find it hard to know what is happening to my tree - or even if it's actually a problem at all...

It was given to me by my sister for Christmas, and was happy inside by a south-facing window for quite a few months. She warned me not to over-water, so I didn't, and we had some new leaves and lots of flowers after 2 months.

Since then leaves started dropping off and have not stopped. Almost all from the bottom of the plant, leaving the lower branches denuded. There are still 4 big lemons on the tree, with what look like new ones forming - and there has been some leaf growth at the top of the plant. We have some new flowers coming out now as well.

We did repot after the first growth spurt, using citrus compost and fertiliser every couple of weeks. I do a thorough water about every 10 days or so, with leaf spraying whenever I can. It gets loads of sun through the windows, and I take it outside every so often when there's no wind - but it only gets direct sun for the first half of the day.

Is this just normal, or should I be looking at changing something? Should I harvest the fully-grown lemons (they look so nice on the tree, though)? Should I be doing some pruning?

Many thanks for any advice you can give.

(Also - how do you upload multiple photos? I have some more showing bare branches with buds on them...)