During the late fall and early winter I get lots of calls about re-potting house plants that are not doing so well. The problem however is only going to get drastically worse if you do indeed re-pot your plant. Re-potting plants at the beginning of winter is a horrible idea for so many reasons. Re-potting causes shock! So what happens when you re-pot a plant is that its root system (which is probably already having issues causing leaves to fall off) now has to catch up to the bigger pot by developing more roots. When the roots need to grow, the plant basically stops growing and waits until the roots fill up the space. Had you not re-potted, your roots would have already been full.
Here is something you may not know...plants like to be root-bound, especially during the winter months. Do not re-pot until spring.
The only times that it is necessary to re-pot at the beginning of winter is if the roots have caused your pot to break or because you brought a plant inside that was planted in the ground (but that re-potting should have been done in September or at the latest, early October allowing plenty of time for recovery). It is also best if you re-pot to the smallest pot in order to develop that root system faster thereby causing less shock.
More than likely, your need to re-pot stems from several factors such as: your leaves are turning yellow or even falling off, your plant has no leaves except at the very top, the stems are stretched and weak and maybe even pale green. None of these problems will be fixed by re-potting.
First you must determine what the real problem is and then fix it. Check your watering habits...number one problem has to do with too much water or your plants sit in water all of the time causing root-rot, weak stems or rotten stems, or leaf yellowing and leaf drop. Trying to fix these problems with fertilizer is even more detrimental to your plants. Fertilizers are only good if applied to healthy plants, not sickly plants. And oh, fertilizers shouldn't be used ever during the winter months.
In summery, do not re-pot, do not try to fix sickly plants with fertilizers and never allow your plants to stand in water for more than one hour. African violets love to sit in warm water for an hour but only when they are dry. Probably the best fix for your plants is to cut back the stems, branches or main trunk drastically (this causes absolutely no shock to your plants-it only helps them to grow back better) and to allow your plants to get pretty dry between watering during the winter months. And remember, there is no such thing as too much sunlight during the winter months. Sunshine is your fix for spindly and pale green foliage.