Alocasia are the ultimate statement houseplant. Native to tropical and subtropical Asia, these spectacular species are instantly recognisable for their long, leaning stems each topped with a large and often glossy leaf. Under the right conditions, this plant can produce new leaves every week during the growing season.
Alocasia is not a single speices. The name refers to a genus that contains many different plants. The most commonly cultivated is Alocasia amazonica, celebrated for its deep green, glossy leaves criss-crossed with pronounced pale green veins.
Alocasia sanderiana, one speices that belongs to the Alocasia genus. It is similar to the Alocasia amazonica but has a narrower leaf. Hoya bicknellii https://commons.wikimedia.org/wiki/File:Alocasia_sanderiana_or_Kris_Plant.jpg
While these dramatic plants are a joy to behold, they are not easy to grow. Conditions have to be perfect for Alocasia to keep looking as good as they do at the plant store. While other plants may overlook a missed watering now and then or tolerate sub-optimal air humidity, the Alocasia can quickly deteriorate if you don't provide it with everything it needs. Generally, they are recommended for more advanced indoor gardeners with a suitable home environment.
Alocasia reginula. Forest & Kim Starr https://commons.wikimedia.org/wiki/File:Starr_080117-1732_Alocasia_reginula.jpg
Temperature, position, and lighting
An Alocasia needs to be by a window that receives a few hours of bright (though not direct) sunlight everyday.
If you live in a temperate climate, adjust your Alocasia's position seasonally. During the summer, an east or west-facing window is better than a south facing window. Direct, high-intensity rays in a south-facing position can burn the leaves. In winter, make up for the weaker sun and shorter daylight hours by switching to a south-facing window.
Alocasia need a temperature range of between 65 and 85°F - anything below this will cause the plant to drop leaves and deteriorate.
Getting the watering right for Alocasia is difficult. It cannot tolerate drought but it's also very easy to over-water. Ideally, the soil should be just slightly damp at all times.
A general rule is to only water when the top 1/4 of the soil is almostdry. When you water, run the soil directly under a tap for 30 seconds until the soil is saturated, then letting the pot stand to allow the excess to drain away.
To keep you Alocasia looking at its best, you need to provide it with a lot of humidity. Ideally, it requires 70 percent humidity with an absolute minimum of 60 percent. This is why Alocasia do their best in a greenhouse. If you are keeping this plant in your house, it's likely you will need to place a humidifier nearby. A brightly lit bathroom window position may also provide enough air moisture.
The right potting mixture will help you achieve the delicate balancing trick that is Alocasia watering.
The potting mix must be well-draining while at the same time being heavy enough to retain some moisture. A good mix would be equal parts houseplant soil, perlite, peat moss, and coconut coir. The houseplant soil provides the nutrients it needs to grow while the coconut coir both retains moisture and lets excess water drain away. The light, porous perlite adds further drainage. Finally, sinceAlocasia prefer a soil pH of between 5.5 to 6.5, the peat moss adds a touch of acidity.
Unlike many easier plants, fertilizer is not an optional extra for the Alocasia. They are fast growers with a large appetite. In the spring and summer, you should be fertilizing every two to four weeks using a 20-20-20 formula. This applies even if you don't want your Alocasia to grow in height. Stop feeding completely in the fall and winter.
Alocasia prefer their roots to be slightly snug in their pot because this mimics their cramped natural environment in the tropical undergrowth. However, this doesn't mean you should let your plant become excessively rootbound. To check whether your plant need repotting, remove it from the pot to inspect the soil ball. Once the root system has encircled the surface, you should move it to a pot that is 2 inches bigger.
Only repot Alocasia in spring or summer. This is when the plant is actively growing and can rebound from any root damage it incurs during the pot transfer.
Older leaves on the Alocasia will yellow and drop off naturally. Remove damaged or yellowing leaves by cutting the stalk its attached to at its base, near the soil, using a sharp sterilized knife or scissors.
Alocasia are not propagated with their leaves or stems but through their rhizomes. Rhizomes are technically part of the stem rather than a root system proper but they perform all the functions that a normal root does.
Remove your Alocasia from the pot and inspect the rhizomes. You may find tiny round nodules growing among them. These are known as corms. Remove the corms using a sterilized knife and, keeping them the right way up, place the corm in a shallow bowl of water with its top peeking out over the surface. Place a glass cover the top to trap humidity, and wait. It may take 1-4 months for the roots to appear.