Horse mint is subtly associated with positive energy flow. As the plant's inherent characteristics resonate with tranquility and healing, it's often advocated for Eastern facing areas. This is suggested not due to any empirical evidence, but a reflective response to the plant's vibrant aroma which typically revitalizes dawn energy.

The chinese plum is generally considered harmonious in Feng Shui terms, credited for bringing a sense of tranquility and well-being. Positioned towards the East, the chinese plum is believed to enhance the Wood element, often associated with health and growth. This view, however, may be interpreted differentially in different schools of Feng Shui, underscoring the importance of individual context.

The mexican plum finds a harmonious synergy with settings oriented towards the East. This may stem from the Feng Shui principle that East is linked to the Wood element, which signifies growth and vitality - features embodied by this vibrant plant. However, it must be acknowledged that Feng Shui interpretations are not universally agreed upon.

The heath spotted orchid aligns well with Feng Shui principles, granting harmonious energy flow when positioned North. This is likely due to its cold-hardiness, reflecting the Water element associated with North. However, the balance may vary depending on personal Chi and other room elements.

The broadleaf cattail aligns well with the principles of Feng Shui, complementing serene surroundings. Its compatibility with the North-facing direction is attributed to water's dominant element in this orientation, which is synonymous with the plant thriving in wet environments. However, perception of this harmony may vary.

The sea-buckthorn signifies determination and vitality in Feng Shui, appreciation for its ability to thrive even in harsh conditions. It's ideally suited for a North facing direction, connected with the water element. The sea-buckthorn's resilient nature might provide a protective energy against the coldness associated with water, eliciting a certain harmony, though one must remember that each placement can invoke unique responses based on personal and environmental nuances.

Japanese fairy bells carries an innately harmonious balance of Yin and Yang energies, making it quite an adaptable addition to any space. When placed in the East direction, it could promote spiritual growth, mimicking the rising sun's energies. This reflects the Feng Shui principle of harnessing growth and familial well-being. However, one should remember that Feng Shui practices can be uniquely personal and results may deviate according to different individuals' experiences.

The wild poinsettia has a curious interplay with Feng Shui, mildly raising the chi with its fiery hues. As the South symbolizes fame and reputation, this plant may fortify one's social status. But remember, the plant’s prominence should harmonize with other home elements. Feng Shui is a holistic practice; imbalances can disrupt the positive flow.