The heliotrope infusing the surroundings with invigorating energy, brings positive change to the environment. Quite apt for the northeast direction; the traditional sector of Knowledge. The subtle mixing of energies may aid in imparting wisdom and enlightenment in a mysterious Feng Shui way. However, interpretations may vary, depending on personal perspective and circumstance.

Possum grape is conventionally associated with fluidity and adaptability, traits echoing the Water element in Feng Shui. Perceived favorably for Southwest-facing areas, it resonates with the Earth element governing this direction, finely balancing its Water essence. However, this harmony may vary, for the ebb and flow of energies is an entirely subjective domain.

The hairy crabgrass aligns well with the principles of Feng Shui, particularly when it faces Southeast. This direction, related to wealth and prosperity in Feng Shui, seems to harmonize prolifically with the hairy crabgrass's natural endurance and growth vigor. Naturally, interactions of energies can be subjective, inviting various interpretations.

The apple-of-peru bears a harmonious resonance with the South, owing to its visually stimulating blue flowers that can create vibrant energy (known as 'Chi') in Feng Shui practices. However, given Feng Shui's highly individual and complex nature, interpretations may vary.

The giant ironweed holds a symbiotic connection with the Southern direction. This association stems from the plant's vibrant purple flowers, symbolizing power and respect in Feng Shui. The South, represented by the fire element, harmonizes with the hardy characteristics of giant ironweed, hinting at sturdy resilience amidst adversities. However, individual circumstances may influence this alignment, emphasizing the essence of personalized Feng Shui practice.

Fishtail fern evokes a harmonious interaction of Yin and Yang energies, contributing to balance and tranquility in a space. When situated northward, it symbolizes growth and progress due to its inherent wood properties, making it a fine choice for enhancing endeavors and projects especially related to career in one's life.

The shumard oak is moderately compatible with Feng Shui principles. Particularly when placed in the Southeast direction, it may possibly tap into the wood element, promoting prosperity and wealth. However, this compatibility can vary greatly, depending on individual interpretations of Feng Shui philosophy and practice.

The moth mullein aligns harmoniously with South-facing areas. As Feng Shui principles suggest, this direction, associated with the energy of recognition and fame, pairs well with the moth mullein's vibrant blossoms that symbolize visibility. The essence of the moth mullein subtly amplifies the fiery, dynamic qualities of the South, while adding a layer of mild tranquility. Remember, individual experiences with Feng Shui can greatly differ.