Alocasia macrorrhiza 'Stingray'
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Although bright, indirect sun is ideal, throw in some morning or evening sun if possible. If it's situated in a shady location, dust the leaves from time to time to improve light-capturing efficiency. Never allow an Alocasia to sit in strong sunlight for extended periods, as too much light will result in a pale, washed-out appearance with possible brown patches forming on the leaves.
Allow around a third of the soil dry out in between irrigations during spring and summer, with monthly waters in the cooler months. Alocasia are usually situated in a well-draining medium, meaning that standing water could be an issue beneath the pot. Use tepid water if possible; many houseplants' root systems are super sensitive to temperature change, so don't get caught out by this as it could result in yellowing leaves. Under-watering symptoms include wilting, little to no growth and greying leaves - these issues are commonly down to too much light/heat, or forgetfulness. Alternatively, over-watering symptoms include rapidly yellowing lower leaves, wilting (root rot), brown spots on leaves, and a rotten stem. Do not situate an Alocasia in dark locations with much water, as root rot and leaf spot disease will quickly arise. For more information on how to address this issue, scroll down to 'Common Issues'.
Create a humidity tray to provide a moist and stable environment for your plant. If the surrounding saturation is too low or the heat too high, its leaf-tips may start to brown over and curl, especially in direct sunlight. Gently hose the foliage down from time to time to hydrate the leaves and keep the dust levels down.
Fertilise every four waters during the growing period before reducing this to every six in the autumn & winter. Although an 'All-Purpose' fertiliser will still do the job, we'd recommend using a specific 'Houseplant' labelled fertiliser as it'll support the vital thirteen nutrients that this species will need to grow.
Regular irrigations are key. Periods of droughts will quickly slip the Alocasia back into its dormancy period, causing stunted growth and a bewildered plant owner. If it hasn't repotted in a while, there may be too many roots and not enough soil to retain moisture, thus leaving the soil to dry out quicker. Click on this link to learn more about a transplant.
Pest damage can also cause issues down the line. Spider Mites and Mealybugs tend to be the usual inhabitants; check the leaves' undersides and along the leaf's central archway (midrib) for possible colonies. Spider Mites are minute, almost transparent critters that roam around the leaf faces in search of chlorophyll, whereas mealybugs are white and are quite noticeable after a while. Both have an 'HQ' for their colonies that must be destroyed in order to reduce the overall population. Click on this link for more information.
Dust the leaves regularly. Although this isn't too much of an issue, a build-up of dust particles can clog up the plant's pores, causing lowered light capturing-efficiency. Wipe the topside of the leaves down once a month to keep levels down and improve growing conditions.
If your Stingray Alocasia begins to wilt, it could be the product of one or many issues, ranging from the environment to your care habits. If the specimen is located in too low light, it may lead to plant-confusion when the window is several metres away. As mentioned in 'Location & Light', most Alocasia will require overhead lighting to complement its growth habit, with anything else causing either wilting or slanted growth. Secondly, irregular watering habits could cause root dehydration, which will eventually lead to wilting. Prolonged droughts will result in a lack of hydration in the upper part of the plant, with root rot doing the same - albeit it with overly soggy compost. Finally, environment shock could be the final culprit of your wilting Alocasia. If the specimen has recently been purchased or relocated, the chances are that the specimen hasn't acclimated itself to the new environment. Be sure to provide a bright, indirect setting with the best possible angle to the light source (overhead or nearby a window). Maintain relatively moist soil, allowing the top third to dry between waters and fertilise every two to four weeks, depending on the current season. If you still have questions about your poorly Alocasia, be sure to book a 1-to-1 Call with Joe Bagley to discuss this further!
Yellowing leaves - it's difficult to accurately pinpoint why this is happening as it could be due to many different reasons. If the lower leaves are yellowing in quick concession, it could be over-watering. Do not allow the soil to become soil or waterlogged; failure to do so will cause root rot and possible death. For severe cases, take the plant out of rot pot to examine for root rot - a transplant may have to be performed. The second reason why its leaves are yellowing could be due to either too much sunlight or not enough water. As mentioned above, under-watering can cause an Alocasia to slip into its dormancy period, but persistent droughts with direct sunlight will cause further damage in the likes of yellowing leaves, stunted growth and wilting.
Leggy or spindly leaves/stems that can easily snap are the result of low light. Increase your plant's light levels by relocating it to within 2m (6ft) of a window (or in the windowsill) that offers up to two hours of early morning (before 9am) or evening sunlight (after 7pm). Don't prune the already-leggy foliage and instead wait for more compact growth that may take up to two months to grow. Feed regularly and maintain reliable soil moisture.
Too low humidity can cause browning leaf tips with yellow halos. Although this won't kill the plant, increase humidity to prevent new growth in adopting these symptoms. Either mist weekly while the heaters are on, or create your humidity tray.
Alocasia is a genus of around seventy species, originating from tropical locations forests in Southeastern Asia and northern Australia. Unfortunately, not much is known about the Stingray Alocasia; some botanists believe that it is an interspecific hybrid, with others leaning towards the idea of it being a naturally-occurring cultivar.
10° - 30°C (50° - 86°F)
H1b (Hardiness Zone 12) - Can be grown outdoors during the summer in a sheltered location with temperatures above 12℃ (54℉), but is fine to remain indoors, too. If you decide to bring this plant outdoors, don't allow it to endure any direct sunlight as it may result in sun-scorch and dehydration. Regularly keep an eye out for pests, especially when re-introducing it back indoors.
Over 0.7m in height and 0.5m in width once they reach maturity. The ultimate height will take between 5 - 10 years to achieve.
Remove yellow or dying leaves, and plant debris to encourage better-growing conditions. While pruning, always use clean utensils or shears to reduce the chance of bacterial and fungal diseases. Never cut through yellowed tissue as this may cause further damage in the likes of diseases or bacterial infections. Remember to make clean incisions as too-damaged wounds may shock the plant, causing weakened growth and a decline in health.
Via Seed or Corm Offset Division.
Corm Offset Division - Your plant will produce several basal offsets that can be separated once they have a sufficient root system, and surpass 25cm in height. If possible, water the soil 24hrs before the main event to reduce the risk of transplant shock, when its dry root systems are over-fingered. Take the plant out of its pot and place your fingers close to the nodal junction - soil may have to be removed for better access. Push the chosen offset downwards until you hear a snap. Separate the foliage and its root system away from the mother plant, mentally noting the high risk of damage. Transplant in the appropriate sized pot with a fresh batch of 'Houseplant' soil. Maintain evenly moist soil and situate it in a bright, indirect location away from any direct sunlight. After eight weeks, treat it like a normal specimen following the care tips above!
As Alocasia is part of the Araceae family, their flowers aren't showy. Much like a Peace Lily's flower body, their flowers consist of a white or green spathe (the spoon-like shell) with the spadix being the site of pollination. Blooms can last up to five days and is usually visible during late spring or early summer around 30cm+ from the soil line.
Repot every two years in the spring, using a 'Houseplant' labelled potting mix and the next sized pot with adequate drainage. Alocasia are far better potbound for several years due to the heightened risk of root rot and repotting-issues (like transplant shock), so only repot if you feel it's wholly necessary - restricted root growth will also increase the chance of blooms, too.
Hydrate the plant 24hrs before tinkering with the roots to prevent the risk of transplant shock. For those situated in a darker location, introduce an extra amount of perlite and grit into the deeper portion of the pot to downplay over-watering risks. Click on this link for a detailed step-by-step guide on transplantation, or via this link to learn about repotting with root rot.
Book a 1-to-1 video call with Joe Bagley if you'd like a personal guide to repotting your houseplant. This will include recommending the right branded-compost and pot size, followed by a live video call whilst you transplant the specimen for step-by-step guidance and answer any further questions!
Keep an eye out for mealybugs, spider mites, scale, thrips, fungus gnats, vine weevils & root mealybugs that'll locate themselves in the cubbyholes and undersides of the leaves, with the exception of the latter two in the soil. Common diseases associated with Alocasia are root rot, leaf-spot disease, botrytis, rust, powdery mildew & southern blight - click here to learn more about these issues.
Members of the Araceae family typically contain poisonous calcium oxalate crystals, with Alocasia being no exception. Other members of this family include Philodendron, Zamioculcas (ZZ Plants) and Spathiphyllum (Peace Lilies). If eaten, vomiting, nausea with a loss of appetite could occur and consumption of large quantities must be dealt with quickly.
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