A red rose is traditionally a symbol of love. Throughout the movie "American Beauty- rose petals are represented, however they are in situations where the love displayed is corrupt or polluted. Their red color seems to highlight the inequities of the love displayed by various characters- the final confirmation of this coming in the form of deep red blood that is the culmination of many of the relationships in the movie. The rose- the traditional and expected symbolic expression of love, hides real feelings and gives a fazade of beauty to otherwise ugly relationships.
Carolyn raises roses. She cultivates them and makes them into beautiful adornments for her perfect home. She wears perfectly matching clogs and gloves to use her matching clippers to cut her perfect roses. She believes, as she states several times in the movie, that "to be successful one must put forth a successful image at all times."" Carolyn bases her self worth on what other's think of her. If she looks perfect than she is perfect. When her husband quits cooperating with this philosophy her world begins to fall apart. She has, up until this time, felt only pragma love towards her family- they fulfill her shopping-list requirements. When they no longer fulfill that she is confused and unsure what to do. Her self love is at risk because people will no longer see her as perfect so she will not be free to love herself. She re-acts by searching out someone to restore that perfection. .
Buddy Kane represents perfection to Carolyn. He appears to live the life and be the person she wants. He takes her husband's place in the world she has created in her mind. Her pragma love turns on him and this love develops into Eros, or erotic love. The affair she has with Buddy is not one born out of romance, or even a physical attraction. But rather it is an outgrowth of her search for perfection. Strangely this affair leads to her beginning to find that there is more to love than perfection.