Some plants can bloom after one to three years, whereas others may take thirty or more years to bloom. A cactus flower can take anywhere from ten to twelve weeks to bloom. Christmas cactus flowers will appear in great profusion over the festive season. The time it takes for a cactus flower to bloom can vary greatly depending on its type. Thanksgiving and Christmas cacti are called “short day plants” meaning in order to produce flower buds, they require fewer daylight hours and/or cool night temperatures. …. If plants are exposed to cooler night temperatures of 55° F, plants will bloom in approximately 5-6 weeks, sometimes regardless of the day length. A cactus flower blooms typically once a year, although some cacti may bloom more than once. The blooming season for a cactus is usually determined by the plant’s environment. For example, if a cactus is in an area with a lot of sunlight, it will likely bloom during the spring or summer. Alternatively, it has been suggested that a small butane burner with a wand is the best method. Use the tool to scorch off the pear's thorns and glochids. Using a burner makes harvesting prickly pear fruit less fraught with peril, as the lack of spines renders the fruit safe to grab. Always leave a few fruits for wild animals and birds. This strange cactus is a hybrid of long and thin triangular tubers, of bluish green color, 6 to 15 cm long; exposed to high light intensity, the edges turn reddish. At the end of the tuber, long, papery spines grow up to 10 cm. It has large, fleshy roots. It reaches up to 60 cm in height and 50 cm in diameter. The blooming time of starfish cacti depends on where they are being raised, the amount of sun and water they receive, the fertility of the soil and the species. On average, you can expect a baby plant to bloom in two years with just one or two flowers. When it is mature, the plant will bloom successively in July to September in North America. Planting Your Seeds. San Pedro seeds should be sprinkled evenly across the surface of your potting mixture. Do not bury the seeds, they only require light and moisture to germinate. Water the seeds gently with rain or distilled water, avoiding tap water because it can often be too alkaline for these cacti. The cactus will not bloom unless the dormancy takes too long, which occurs as soon as the flowers appear in the spring. Your cactus’ flowering season is determined by the species, the age, and the climate in which it was grown. Desert cacti bloom in both the spring and summer. The majority of cacti blooms last two to three weeks, but some Secret #2: Provide at least 12 hours of darkness. As a short-day plant, Christmas cactus needs 12 to 24 hours of darkness every day to enter a flowering period. How long do cactus flowers last? Typically, most cacti flowers last for 1-day. A few c6p6.