If a magnolia has been flowering in recent years and then fails to flower it could be one of several reasons.The first might be that it has just been caught by the weather.In this case you should see some damage to the leaves and the buds or see that the buds have just failed to open in the spring. However this is the unlikely case of non flowering since Magnolias are very hardy.A more likely cause is that the soil has become to alkaline or that the soil lacks potash and or Magnesium.This can be cured by adding a top dressing around the plant of a general fertilizer around the base of the plant and then a mulch of garden compost or well rotted farm yard manure,this will lower the soils pH.<\/p>\n