its called etiolation and its where a plant stretches and grows thin towards light. it grows thin because it does not get enough light to produce glucose to form cellulose which is needed to build cell walls inside the plant. So it grows according tot the light it is given.Click to see full answer. Just so, why is my cactus changing shape? Give more water to a wilting cactus. If the soil is fully dry, water it thoroughly, allowing excess water to drain out the bottom of the pot. If the soil is not dry, the problem could be a condition called etiolation, where the rounded or stem-shaped parts of the cactus become narrower.Similarly, is my cactus getting too much sun? Be aware that Succulents can easily get sun-scorched and dried out if the heat and sun exposure is too intense. My cacti, however, are outside and exposed to the sun all day. You don’t want to sunburn your plant with too much sun exposure, nor do you want to drown the little guy! People also ask, should I trim my cactus? Cactus are low maintenance plants that generally thrive with neglect and do not require a lot of pampering. It might surprise you to find that cacti can and do need to be pruned now and then. Cactus pruning is not always necessary and when to prune a cactus plant will depend upon why you are trimming it.What does an overwatered cactus look like? Symptoms of Overwatering in Cactus Their roots rot easily, and too much water can kill them. As they get waterlogged, the roots will die and rot. As more roots die, the plant aboveground will start to deteriorate, usually turning soft and changing color. By this point, it may be too late to save it.