You didn’t give it the right amount of light – Aloe, cacti and euphorbia milii require a lot of light, so a cubicle or the corner of your living room isn’t the right place for them! On the flip side, begonias, and epiphyllums thrive in low-light or filtered-sun environments. Simply moving the plant to another spot in the house could work wonders. You brought it outside for the summer – when a plant, even one that requires a lot of light, gets moved to direct sun after spending the last nine months indoors, it will burn quickly and easily! It might also start rotting if there’s been too much rainfall. If you want to move your plants to the open air, make the transition gradually and keep tabs on moisture levels. You over or under-watered – since succulents and cactus plants prefer dry soil, watering daily will harm them! Once a week is plenty. If you often forget to water or spend a lot of nights away from home, they’re a good choice. Plants that are blooming require watering more often than when they’re in a dormant period. As a general rule, check the soil and tips of the leaves to see whether they’re dry, indicating that the plant needs water. When you water plants, be careful not to get droplets on the leaves; this promotes fungal growth. You didn’t protect it from pests – spider mites, mealy bugs, and scale insects prey on your household plants! You can mix neem oil concentrate in a spray bottle with water and spritz it on your plants every one to two days. It smells like citrus. Neem oil compounds will repel some insects by disrupting their reproductive or developmental cycles. It also deters some insects from feeding on foliage.