Flower essences contain the vibration / imprint (energy) of the plant. It helps bring us into a state of resonance with our true essence, our perfect-self our God-self within. Since this is energy at work; these essences are more powerful than herbs or other extracts.
The body has a complex electrical system that is present in and connects with every cell. When this system is compromised by various stresses, traumas and unhealthy situations in life, these circuits break down and cause the physical, mental, emotional and spiritual imbalances and malfunctions. Flower essences help to reconnect these circuits on a cellular level and allow the body to return to a state of balance and health. 

Rescue Remedy is the most commonly known and used. It helps to deal with any emergency or stressful event. Taking a driving test, exam nerves, speaking in public, after an accident or an argument - there are countless uses for Rescue Remedy, it helps people, and animals.
Bach flower remedies address primarily the emotional level of consciousness.
Dr. Bach believed that the primary cause of each illness comes from unbalanced and/or extreme emotions.
He discovered that specific flower essence balances specific zodiac sign personality type, contributing to well being, spiritual growth and personal satisfaction. 

Agrimony -mental torture behind a cheerful face, addictions, timid, victims of bullying, over sensitivity (SAGITARIUS)
(For people who hide their true inner feelings deep within behind a mask of cheerfulness. They are one with intense emotional suffering, and hidden anxiety. This remedy will help them to take things more objectively, and to better communicate with others.)
Aspen - fear of unknown things
(For those who suffer fears which arises for no apparent reason - so called "free-floating anxiety", can be manifested by goosebumps, trembling, sweating, fluttering sensation in the stomach, terror, panic, sleeplessness, etc. Aspen promotes self-confidence, self-trust, and selt-believe.)
Beech - intolerance
(For those constant critics, who do not understand others, and are easily irritable. Aspen will help them to be more tolerant, to see more beauty and good in all that surrounds them.) 
Centaury - inability to say 'no' (VIRGO)
(For those who are too easily dominated and manipulated by others, who are too submissive. Centaury can help those to stand for themselves, to define boundaries, to define their needs, to initiating things by themselves and for themselves.)
Cerato - lack of trust in one's own decisions (TAURUS)
(For those lucking faith in their own judgment, who are not able to make a decision without asking everyone, for those needy of constant reassurance. Cerato gives confidents to think and act for oneself.)     
Cherry Plum - fear of the mind giving way
(For those who are emotionally stressed to the point that they are afraid of causing the damage, of loosing control of their actions. Cherry Plum can help to deal in crises, to give a courage to deal with the situation at hand, it can ease the crisis.) 
Chestnut Bud - failure to learn from mistakes

Chicory - selfish, possessive love, manipulative (SCORPIO)
Clematis - dreaming of the future without working in the present, forgetfulness, impractical, absentminded (CANCER)
Crab Apple - the cleansing remedy, also for self-hatred
Elm - overwhelmed by responsibility
Gentian - discouragement after a setback, lack of faith, pessimism, lost spiritual connection (GEMINI)
Gorse - hopelessness and despair
Heather - self-centeredness and self-concern
Holly - hatred, envy and jealousy
Honeysuckle - living in the past
Hornbeam - procrastination, tiredness at the thought of doing
 something
Impatiens - impatience (ARIES)
Larch - lack of confidence
Mimulus - fear of known things, phobias  (CAPRICORN)
(For those with fear of failure and of letting people down
Mustard - deep gloom for no reason
Oak - the plodder who keeps going past the point of
exhaustion
Olive - exhaustion following mental or physical effort
Pine - guilt
Red Chestnut - over-concern for the welfare of loved ones
Rock Rose - terror and fright, deep-rooted fear, rigid (PISCES)
Rock Water - self-denial, rigidity and self-repression
Scleranthus - inability to choose between alternatives, indecisiveness, confusion, mood swings (LIBRA)
Star of Bethlehem - shock
Sweet Chestnut - Extreme mental anguish, when everythin has been tried and there is no light left
Vervain - over-enthusiasm, hyperactive, stressed (LEO)
Vine - dominance and inflexibility
Walnut - protection from change and unwanted influences
Water Violet - pride and aloofness (AQUARIUS)
White Chestnut - unwanted thoughts and mental arguments
Wild Oat - uncertainty over one's direction in life
Wild Rose - drifting, resignation, apathy
Willow - self-pity and resentment
Rescue Remedies -  emergency or stressful event. Taking a driving test, exam nerves, speaking in public, after an accident or an argument - there are countless uses for Rescue Remedy.

 

Just as he had abandoned his old home, office and work, so now he abandoned the scientific methods he had used up until now. Instead he chose to rely on his natural gifts as a healer, and use his intuition to guide him. One by one he found the remedies he wanted, each aimed at a particular mental state or emotion. His life followed a seasonal pattern: the spring and summer spent looking for and preparing the remedies, the winter spent giving help and advice to all who came looking for them. He found that when he treated the personalities and feelings of his patients their unhappiness and physical distress would be alleviated as the natural healing potential in their bodies was unblocked and allowed to work once more.

In 1934 Dr Bach moved to Mount Vernon in Oxfordshire. It was in the lanes and fields round about that he found the remaining 19 remedies that he needed to complete the series. He would suffer the emotional state that he needed to cure and then try various plants and flowers until he found the one single plant that could help him. In this way, through great personal suffering and sacrifice, he completed his life's work.

Dr Bach passed away peacefully on the evening of November 27th, 1936. He was only 50 years old, but he had left behind him several lifetime's experience and effort, and a system of medicine that is now used all over the world."

Bibliography:
The Dr Edward Bach Centre, UK

NOTE:
Specify Required  Essence in special request box at the Checkout -