The philodendron Fat Boy aligns harmoniously with Feng Shui principles, reputed for radiating positive ch'i due to its lush, green foliage. It favors an East-facing direction, symbolizing growth and renewal, which are akin to its own nature of thriving with minimal care. Remember, Feng Shui is subjective and experiences may vary.

As per Feng Shui, the air-flowered air plant aligns harmoniously with the energy of the Southeast direction. This is due to its air-associated nature, which enhances the Wood element of this direction, fostering growth and prosperity. Remember, Feng Shui interpretations can vary, and hence should be personalized for each individual.

The air plant has a level of compatibility with Feng Shui principles, but the nuances are tricky. As a metal element, it harmonizes well when facing West, which is traditionally governed by this element. This cultivates relationships and fosters productivity, but one must exercise judgment when positioning the air plant. Remember, the balance is key in Feng Shui.

From a Feng Shui perspective, the earth star plant presents a harmonious presence. Most agree that its slender leaves and striking colors symbolize a balance of energy, making this plant a beneficial asset in uplifting any space's livelihood. Predominantly, it's often associated with the Southwest-facing direction, due to its perceived qualities promoting healthy relationships and marital happiness, which fits well with the Earth Element associated with the Southwest. Nevertheless, it's important to remember that Feng Shui is highly subjective and personal, results may vary from one individual to another.

Begonia promotes balance and serenity, making it a favorable plant in Feng Shui. Positioned facing North, it aids in the cultivation of career virtues, as water is the governing element of the north in Feng Shui, and begonia thrives in a moist environment. Remember, Feng Shui is about personal interpretation and perception, so consider your space and intuition.

Blue grape hyacinth harmonizes well with North-facing areas, a direction that corresponds to water in Feng Shui tradition. As blue grape hyacinth prefers moist, well-drained soils, it symbolically mediates the water element, creating a delicate balance. However, sensitivity to Feng Shui energies can vary individually; this guidance serves to promote harmonious plant placement.

The nikko fir aligns well with the Southeast direction, which is linked with wealth and prosperity in Feng Shui. This is because its upwards growth subtly stimulates the upward movement of chi, thus enhancing financial energy. However, personal experience can vary, and this should serve as a guideline rather than rule.

The korean fir is seen as having agreeable Feng Shui characteristics, its dark green needles implying strong wood energy and growth. Positioned in the East, it may enhance the family and health sector, as East is typically associated with wood energy in Feng Shui. Notwithstanding, each individual's Qi might interact differently with the korean fir, asking for discretion in its placement.