Dead plants are not only a hazard to your health but are bad luck plants in every tradition. Keeping dead things attracts negative energy and invites malicious spirits.
Some traditions consider fake plants to invite deception, especially ones made of plastic and other artificial materials. Artificial plants also attract dust, and they fade over time.
These stunted trees are held back from reaching their full potential. Feng Shui practitioners and Vastu experts recommend you stick to plants that promote growth, not actively suppress it.
Cactus plants are discouraged in Feng Shui, and the Crown of Thorns is especially disruptive. As the plant matures, its stem becomes long, bare, and covered in formidable spikes.
The reason Philodendrons are considered unlucky is due to their toxicity. Since toxicity brings bad energy in indoor spaces, some say that these beauties belong strictly outdoors.