The pencil cactus (aka Euphorbia tirucalli or ET) is a rugged succulent plant that can grow to over 30 feet high in the wild. This versatile plant has many names, including: Fire plant. Fire stick cactus. Fire sticks plant. Fire stick pencil cactus. The succulent fire plant can also be kept to a more moderate height of 6′ to 8′ feet when How To Care For A Moon Cactus. Moon cactus care is ideal to ensure the succulents bloom with vibrant flowers in late spring or early summer. Provide Adequate Sunlight. For your cactus moon to last, you will need to keep them indoors, whether in a greenhouse or near a bright window. If you plant it outdoors, you will need to protect it from the sun. Like all succulents, the Star Cacti are vulnerable to rot due to over watering or standing water. To avoid rot, keep your watering in check by keeping in mind the golden rule of succulent watering; keep your plant dry between watering. If your cacti’s soil feels dry, then you should water it, depending on the season. How to care for cacti: Grow cactus plants in fast-draining soil and water when the potting mix dries out. Cacti thrive in bright sunlight up to 12 hours a day. In summer, cactus plants may need watering every week but in winter, every four to six weeks. The Bunny Ear Cactus (Opuntia microdasys) is deceivingly sweet.Instead of individual spines, this species has short, barbed hairs that grow in groups, called glochids. They are one of the fastest growing species of cacti, making them fun to watch get larger over t Poke several small holes in the soil 1 inch (2.54 cm) apart using a pencil. Make the holes about 1/8 inch (0.4 cm) deep. Place the saguaro seeds in the holes and lightly pinch the soil closed over them. 4. Cover the seeds. [1] Place plastic wrap securely over the pot. Poke holes in the plastic wrap to aerate the soil. In the growing season, the plants should be watered at least once a week. When watering, the soil should be given a good soaking, allowing excess water to drain away. Allow the compost to dry out slightly between each watering. This is the time of year when the plants enter a rest period. Thimble Cactus Care. To care for a Thimble Cactus give it well-draining soil that will dry out between waterings. A 50/50 mix of non-organic/organic works wonders. It thrives best in temperatures between 70°F and 80°F (21°C to 27°C). Temperatures should not be below 25°F to 30°F (-3.9°C to -1.1°C). 4sASW.