Underwatering: There is a big myth that cacti don’t need water, but that is not true. Browning is a relatively common problem that many cacti gardeners have to deal with. Warm, moist conditions accelerate the production of fungi spores and increase bacterial production. To kill them, you will need to physically catch and remove them by hand. You can also try fungicides, but they usually fail to treat the plant fully. Sun burn is caused when you let your cactus face direct sun light straight after rest period, without shading it beforehand. Your cacti might also become infected with mites. Stagnant air, high humidity and low temperatures can cause slow water absorption. In-ground plants have similar requirements. Give them a spot of sunlight and a minimal amount of care, and they will grow healthily and happily. Another reason for the black spots could be a change in temperature has occurred. The open areas may be from insect or animal activity, damage from inanimate objects or heavy weather, such as hail. If you’ve begun to see black spots forming on your cacti, you can easily resolve the issue by cutting off any infected areas of your plant. A common problem is soft spots in the flesh of the plant. When treating your cactus, make sure to shield it from the direct sun to avoid burns. In fact, one of the cacti's only real enemies is too much water. Your cactus might rot due to different causes – mainly bacteria and fungi, but can be also viruses. If a plant looks like it needs more light, move it to a windowsill. Scale can attack many types of cacti. Here’s How to do it. To add the icing on the cake, it’s a complete list – meaning you don’t need any article on this subject.eval(ez_write_tag([[300,250],'hortzone_com-medrectangle-4','ezslot_7',140,'0','0'])); Discoloration, shakiness, and mushy roots are often signs of cactus root rot. To make it, mix some soap with water and spray your cactus with it. Get Busy Gardening: Why Is My Cactus Turning Black On Top? Sometimes, this type of rotting could also be caused by animals and bugs feeding on the plant, or someone could have brushed it and left a wound behind. Cactus is mainly opening its stomata at night – to reduce water loss. For this, you will need to sterilize shears or scissors (use fire or rubbing alcohol), and cut all the dead roots and all rotten parts, even up to a stem if needed. Should I cut the new pad off the bottom plant? Most cacti diseases are caused by bacteria, viruses, fungi and other microorganisms. If you overwater your cactus in winter, it won’t use the water, and the plant is likely to start rotting.