amany,
I have a 7 year old jade, until 2 years ago I lived in NJ where this beautiful plant grew during the spring and summer and bloomed late fall early winter. Things have changed for it up here in MA, for some reason it seems to put out growth year round now and has not gone dormant even with reduced watering and temperatures over the past two winters. Maybe something to do with global warming? LOL
I used to put it outside in the summer on a partly shady covered porch in NJ. I have not put it out since moving here to MA and it may need the summer outdoors to force a dormancy or flowering state. I water about 1 every 6 weeks over the winter, it's a large plant about 18 inches tall and 2 feet wide.

It is really diffiucult to grow them in tiny pots, they dry out faster, and there is no room for the roots to grow, so then the leaves don't grow. In the Spring put it into a 6-8" pot and watch it take off. Often just a change of soil will give it a boost. Mine flower now, and will start to put out new growth after the flowers dies.
I also take it out of the pot then, give in new fresh soil, wash off the roots and trim them back 1/3 also I trim off the top of the plant only 1/3. This keeps the plant in proper perportions to it's self, no hanging branches that can break off. This is also bulk up the trunk which so many of you want. The change gives the plant a shot in the trunk (arm) to start growth.
If I didn't write this to suit anyone you have my permissiion to edit my masterpiece. ";o\ Norma

I think it was too humid in Detroit for my jades to grow last summer. It caused them to go into dormancy. With all that humidity, the need for water was much lower.

They're growing steadily now. A little slower than in October and November though. I'm trying to learn to let the leaves tell me when they need more water. Rather than a schedule or disturbing the roots by sticking my finger in the pot all the time.

I'm in Mi also and my Jade has been growing a lot of new leaves in the past couple of months. It is new so I can't tell you yet how it will do at other times for me, but it's definitely growing now!

Jade plants seem to be what I've heard referred to as "opportunistic growers". They don't like the extreme heat in summer, and will tend to grow when temps are more moderate, and they have some water. I keep them dry in the winter, and try to encourage spring and fall growth with more water at those times, but as many of you have noted, they will grow in winter, too. Always give them as much light as possible when they are growing, to keep the stems from streching out.

I too am finding that to be the case, Rjm.

I think we'd all benefit by simply paying attention to how our jades and other plants (especially succulents), are adjusting themselves to our home environments. In terms of heat, humidity, light, etc. That way someone in the southeast isn't confused about why his or her plant is collapsing when he followed a midwesterner's or northwesterner's advice perfectly.

I guess we just have to let our jades tell us how to grow them by responding to what they do:
Lots of humidity and no growth - hold off on water.
Nice temps (between 50 - 85), low humidity and new growth - water when dry.
Flat leaves - water.
Growing, but the leaves are still very full and plump - water, but not right away.

I think that will work better for us than figuring, "Hmmm... It's July, so I'd better water once per week.". Or, "Yes, my jade is growing like crazy at the end of November, but no water until March.". Just because that works for people in some parts, doesn't mean it will work for the rest of us.