Chinese mahogany aligns harmoniously with the East-facing direction. This is mainly due to the plant's oriental origins, symbolizing renewal and growth in Feng Shui philosophy, which resonates well with the East's inherent energy. This understanding, however, can be subjective and varies among practitioners.

Straw foxglove exemplifies steady growth and vitality, making it an intriguing choice for Feng Shui enthusiasts. Its sunny hues mirror Earth energies, fostering stability and grounding. When situated to face the Northeast, it could possibly amplify spiritual insight and personal growth due to this direction's association with spiritual enlightenment and self-cultivation in traditional Feng Shui philosophy. Remember, harmony in placement is deeply personal and should mirror one's own intuitive sense of balance.

The erect prickly pear holds symbolic potential in Feng Shui, particularly in promoting both protective and healing energies. Its compatibility with the Northeast direction might be due to this area being linked to personal growth and self-cultivation in Feng Shui, harmonising well with the plant's resilience.

The deer fern plant slightly veers towards the mellow aspects of Feng Shui. Its perfectly balanced shape signifies equilibrium, invariably harmonizing energy within a space. Positioned towards the Southwest, it taps into Earth energy, drawing stability and nourishment into your surroundings, a typical Feng Shui notion tying Earth elements to this direction. As ever, individual experiences may fluctuate due to the esoteric nature of Feng Shui.

The scaly male fern is deemed highly suitable in Feng Shui practices, especially when placed in the South. Its robust form represents unyielding strength, mirroring the flaming energy of the South, the domain of the Fire element. However, as an art of balance, Feng Shui is vexingly elusive, and the suitability of the scaly male fern can vary according to personal circumstances.

The chinese red pine is held in high esteem in Feng Shui. Its robust structure symbolizes fortitude and resilience, possibly attracting good health and prosperity. Facing East, the plant's energy is theorized to be harmonized, as East represents Wood in the Five Elements, corresponding to the very nature of the chinese red pine. However, interpretations may vary across practitioners and clients.

The silver linden is noted for its exceptional compatibility in the Eastern aspect of one's space in Feng Shui. It's believed its rounded shape symbolizes completeness, promoting harmony. However, the depth of this connection undeniably resides in the perspective of the beholder.

Palmer's penstemon might harmonize quite well in a Southwest-facing direction, often attributed to the Earth element in Feng Shui. It subtly hints at a sense of balance and stability in life. However, interpret this as you will, and remember Feng Shui's essence lies in aligning with personal preference and comfort.