Since it's already august, the fall will kick in a lot faster then one would imagin. I was wondering what you guys do as preparation for the winter when it comes to fertilizing and temperatures.

I used the stuff I red or heard on the web as wel as this forum topic:
link

First point: fertilizers
- When do you stop fertilizing? Do you actually stop fertilizing or do you adjust the amount? Do you use pooring and/or foliar feeding during winter? When do you adept your fertilizing pattern(end of winter, beginning of spring,later e.a.) for the next summer season? What fertilizer do you use during the winter?

Second point: temperatures
- I hear people keeping the temperature between 0 and 5°C(just above freezing) while others go for the range of 5 to 10°C.
The link gives a pottemperature of about 20°C but that is absolutely hot to achieve isn't it? That doesn't even sound like a winter temperature to me.
In winter, temperatures go below zero here so that would be impossible to achieve in an easy manner. And also, why does the pot temperature has to be 20°C? Even in Italy the outside temperatures decrease as low as 3°C at night and 12°C during the day which makes soil temperatures much lower then 20°C.
So I was wondering at first why you would recommend temperatures that high(for soil) and what are the minimum and maximum temperatures (airtemp. e.a.) at night and during the day.

How I did it (managed to keep it alive during the winter, but lost all its leaves at the beginning of spring): I just stopped watering and put the plant in the garage where the temperatures stayed above zero (during the day, probably froze during the night though) with a thick glass window that provided some light. When the weather was getting warmer(about 5°C during the day) I moved the plant in the greenhouse to give it more light.

I put my plants in the lightroom (veranda) during the winter months. Temperature in there doesn't drop much below 8°C even when it is deep freezing outside (-10°C or so) as there is a heating element from the central heating in there with a thermostatic valve that kicks in when temperature drops below 10°C. At cold but bright sunny winter days temperature can easily go up to 20°C.

As for watering: I make sure the soil never dries out (soil should NEVER be dry for citrus), but in winter months it can take a while before the soil starts drying. I think I water every two weeks or so. I still apply some fertiliser (Sunplant Citrus), about 1/3 to 1/2 the amount given during summer months. If you have some fruit on your plants and regularly measure the size of it, you'll notice it keeps growing slowly during winter months.

You may also notice some leave drop during winter. Some plants only lose older leaves but other plants may lose young leaves too. My buddha's hand tree, for instance, lost ALL of its leaves last winter, but it recovered nicely in spring and looks perfectly healthy now with lots of blossom.

By the end of January all my plants came back to life with new flushes and flower buds.

I fertilize the same amount year around with a 25-5-15 fertilizer. During the winter months, my trees are inside a greenhouse. Concerning temperature. A citrus tree will live at any temperature above freezing, but a citrus tree becomes "dormant" at temperatures below 55.4F. Therefore, if your tree is kept in winter storage at a temperature below 55.4F it will not produce any growth at all. If you wish your tree to continue a growth pattern during the six months of winter, you must insure that the temperature is greater then 55.4F. Of course at the minimum temperature of 55.4 the tree will just barley produce no growth to the minimum of growth. Therefore, growers who wish not to lose six month of growth, always keep the tree at a temperature between 64 to 70F. to achieve an acceptable growth pattern. 78 to 83F is the perfect temperature for the most optimum tree growth, for many citrus varieties. - Millet (513-)