Hello there blandford, The first thing you need to do is to verify the variety of Magnolia you have. Flowers are part of the natural reproductive cycle of plants. Depending on the type and variety of plant, flowers come forth at different times of the year based on various climatic cues. The magnolia flowers early, blooming in March or sometimes even late February (depending on the region).
As far as I know the DECIDUOUS ones flower early. the evergreen ones, more so in summer. (North America so I could be all wrong!!!)
I have a Little Gem evergreen magnolia. I have had it about 18 years so I cannot remember how soon it bloomed.