March is the second best time of the year to repot Junipers and non-tropical evergreen plants. We still have enough warm weather for the roots to establish themselves before the winter sets in.
Feed your plants with fertiliser that is very low in nitrogen to give your plant strength for the winter.
Sprinkle a very low dose of trace elements on your pots if your fertiliser doesn't contain any.
For plants that are not being repotted: remove a little of the topsoil from the pot with a stiff brush and replace with fresh Bonsai Soil Mix.
It is a good idea to remove all dead needles from junipers as they can harbour pests and encourage fungus. I find that an old toothbrush is excellent for this job.