Selenicereus grandiflorus is the largest flowering plant species and belongs to the genus Selenicereus. It has several other common names, such as queen of the night, night-blooming cereus, large-flowered cactus, sweet-scented cactus, or vanilla cactus. 

Native to South and Central America, specifically countries like Mexico, Guatemala, and Venezuela, Selenicereus grandiflorus can reach a mature size of around 20 feet in height. With its long, triangular stems and spines, your Selenicereus grandiflorus is considered moderately fast-growing. With proper care and conditions, you can see noticeable new plant growth and development over time. 

The night blooming flowers of Selenicereus grandiflorus are large, about 15 inches wide, white, and have a delicate appearance. The white flowers of tree species only last for one night in the spring, but they are definitely worth the wait. The specific epithet grandiflorus means 'large flowered' in Latin, which describes its elusive blooms well. These large flowers, combined with their beautiful aromatic fragrance, make them a stunning sight to behold, especially when they bloom at night. 

The fragrance of the flowers adds to their charm and beauty. The real Queen of the Night (Epiphyllum oxypetalum) or Night-blooming Cactus, also known for its stunning flowers and fragrant scent, creates a magical event in your garden.  

With a red edible Selenicereus grandiflorus fruit that is visually appealing and delicious, the plant has traditionally been used for medicinal uses, with its stems and flowers believed to have antioxidant properties, making them suitable for herbal remedies.

This night-blooming cereus cactus is an extremely rare plant in cultivation and is often confused along with 10 other night-blooming cereus genera; as most plants under this name belong to other cactus species or hybrids such as  Peniocereus greggii, Hylocereus undatus, Echinopsis pachanoi, Cereus jamacaru, and Cereus peruvianus. Each species has its own unique characteristics and charm, making it fascinating to explore the diversity within this group of cacti. 

Fortunately, Selenicereus grandiflrous is not considered toxic to humans or pets. However, it's always a good idea to practice caution and keep plants out of reach of curious pets or small children. 

Watering Needs 

When it comes to watering, Selenicereus grandiflorus prefers to be kept on the drier side, so you don't want to overwater it. 

A good rule of thumb is to water your Selenicereus grandiflorus when the top inch of the soil feels dry to the touch. This usually translates to watering it every 1-2 weeks, depending on the climate and the conditions in your home. When you do water, make sure to give it a thorough soak. Water the soil until it's evenly moist, but avoid leaving it sitting in water. Allow any excess water to drain away, as waterlogged soil can lead to root rot. 

During the winter months or when your night-blooming cereus is in its dormant period, you can reduce watering frequency. This allows the cactus to rest and conserve energy. 

Remember, it's always better to underwater than to overwater your Selenicereus grandiflorus. It's a resilient cactus plant and can tolerate periods of drought better than excessive moisture. 

Light Requirements 

Providing enough light for these desert cacti is one of the most important aspects of their care. It is important to grow Selenicereus grandiflorus in areas that receive at least 4-6 hours of bright, direct light every day to keep them happy. 

If you're growing Selenicereus grandiflorus indoors, it's important to provide it with enough light. If your queen of night doesn't receive sufficient light, it may become leggy and have weak growth. You can supplement natural light with artificial grow lights to ensure it gets the right amount of brightness. A good location for it would be near a window with a sheer curtain or in a well-lit room away from direct sunlight. 

During the warmer months, you can even move your cactus outdoors to a partially shaded area. Just make sure it's protected from intense afternoon sun, as direct sunlight can scorch its leaves. 

Remember, finding the right balance is key. Too little light can result in weak growth, while too much direct sunlight can cause sunburn and damage your Selenicereus grandiflorus. So, aim for bright, indirect light and adjust as needed based on your specific growing conditions. 

Optimal Soil & Fertilizer Needs 

Like several other Selenicereus species, it favors very airy, sandy soil that drains well. Planting them in ordinary soil will result in compacted aerial roots, stunted growth, and, most likely, root rot. Instead, make or buy a well-draining potting mix, or ideally, use our specialized cactus potting mix that contains over 5 natural substrates and mycorrhizae to promote the development of a strong root system that helps your Selenicereus grandiflorus cactus to thrive. 

When it comes to fertilizing, Selenicereus grandiflorus doesn't require excessive feeding. During the growing season, which is typically late spring, you can fertilize it once a year with a balanced (5-10-5), water-soluble NPK fertilizer. Make sure to dilute the fertilizer to half or quarter strength to avoid overfeeding. 

During the dormant period in winter, you can reduce or stop fertilizing altogether. This allows your queen of night cactus to rest and prepares it for the next growing season. 

Remember, it's always better to under-fertilize than to over-fertilize your Selenicereus grandiflorus. Too much fertilizer can cause excessive growth and weak stems. 

Hardiness Zone & More 

When you are growing your Selenicereus grandiflorus indoors, it prefers a warm climate in temperatures between 60°F and 85°F. So, keeping it in a cozy spot in your home where the temperature stays within this range will make it happy. 

If you are growing Selenicereus grandiflorus outdoors, it is typically well-suited in USDA zones 10 to 12. This means it can tolerate minimum temperatures of 30°F to 40°F. If you live in a region with colder winters, it's best to grow it as a potted plant that can be brought indoors during freezing temperatures. 

In terms of humidity, Selenicereus grandiflorus is adaptable and can tolerate a range of humidity levels. However, it generally prefers moderate humidity. Aim for around 40% to 60% humidity, which is comfortable for both the cactus and you! 

Remember, in extremely cold temperatures, it's important to take precautions to protect your Selenicereus grandiflorus. If you're growing it outdoors, consider covering it with a frost cloth or bringing it indoors during freezing conditions. This will help prevent damage to the cactus plant.  

Additionally, the Selenicereus grandiflorus Queen of the Night can be propagated by seeds and cuttings. To propagate Selenicereus grandiflorus, avoid direct sunlight and water sparingly.  With patience and care, successful propagation can be achieved. 

The Bottom Line 

Overall, the Selenicereus grandiflorus is a large flowered cactus native to Central and South America. It thrives in warm temperatures between 60°F and 85°F indoors, and USDA hardiness zones 10 to 12, with moderate humidity around 40% to 60% ideal. To prevent damage in extreme cold temperatures, it is essential to cover or bring it indoors. Despite its beauty, it requires proper temperature, humidity, and protection in colder conditions. 

With the help of Selenicereus grandiflorus, you'll start to spend less time maintaining your garden and more time taking in its beauty!