Add Gravel. Start your cactus planter out with a wide dish that is at least 3 inches deep. To ensure proper drainage of your garden, pour a 1-inch layer of pea gravel into the bottom of the dish. Doing so will help water drain faster out of the bottom of the pot so your plants aren't sitting in too much moisture. In spring through summer, water the plant when the soil is dry to the touch. Make sure any saucer you have is emptied of water to prevent root rot. Another important part of Huernia cactus care is temperature. If you are growing the plant outside, it should be moved indoors if temperatures drop to 50 degrees F. (10 C.). If your cactus is hesitant to bloom or is on its second blooming cycle, you can take some steps to actually force your plant to bloom at a particular time. The easiest method is to introduce your plant to more cold temperatures. For six or more weeks, put your cactus outside overnight, if temperatures are around 50-55 degrees. Caring for Houseplants. Caring for houseplants the right way is just as important as picking the right one. With a little preparation and some care, you can learn how to take care of your house plants and keep them looking beautiful. If you notice problems, use our helpful tips on houseplant care to solve them before they get serious. Suppose you get too aggressive and cut pieces unnecessarily. In that case, you could damage the plant by removing pieces that were providing critical nutrients to the rest of the plant. 5. Discard or Reuse Trimmed Pieces. Dead, dried, or diseased pieces of cacti should be discarded in the trash or compost pile. 5 days ago · For most cactus diseases like powdery mildew, mealybugs, and scale insects, simple houseplants remedies like neem oil, insecticidal soap and a good strong jet of water will do. For pests like red spider mites and aphids, insecticidal soap works well as a pesticide. For diseases like brown rot, take away the infected plant parts and sanitize 9. Indoor Cactus 'Euphorbia Trigona' (African Milk Tree) This indoor cactus plant is one of those easy cactus varieties that make everyone feel like a cactus care expert. This cactus can grow more than 8 feet tall, but it is a slow grower and is unlikely to grow much past 4 feet indoors. By the end of the flowering season (usually in fall or six to eight weeks before the next flowering period), the Christmas cactus needs to become dormant. During this period, the plant needs less humidity, a cooler environment (50-55°F/10-12°C), and less light (12-14 hours of darkness). Schlumbergera flowering. 9XST.