Elephant's Ear Care (Alocasia macrorrhizos 'Borneo Giant')

Alocasia macrorrhizos 'Borneo Giant' thrives in bright, indirect light with some gentle direct sun.

• Provide 3–4 hours of soft morning sun with bright, filtered light for the rest of the day; avoid harsh midday and afternoon sun that can scorch leaves.
• Tolerates partial shade, but in deep shade leaves elongate, lose vigor, and overall growth slows noticeably.
• In summer, use light shade cloth or dappled tree cover; in cooler seasons, move it where it receives more open sky or longer bright exposure.

This large aroid prefers consistently moist, airy soil without becoming waterlogged.

• Outdoors in growing season, water when the top 3–5 cm of soil feel slightly dry, then soak thoroughly so excess drains away.
• Use rich, loose soil with good drainage; puddling around the base, sour smell, or yellowing lower leaves suggest overwatering and poor aeration.
• In cooler months, allow the top layer to dry a bit more between waterings; drooping, thin leaves and dry edges indicate underwatering.

This plant grows best in warm, stable conditions similar to a tropical summer.

• Ideal growth occurs at 70–85°F (21–29°C); growth slows noticeably below 65°F (18°C).
• Avoid temperatures below 55°F (13°C); brief dips near 40°F (4°C) can damage foliage, and frost may kill the plant to the ground.
• Tolerates short heat waves up to about 95°F (35°C) if soil moisture is consistent and humidity is moderate; provide shade and shelter from hot, drying winds.

This species prefers consistently high humidity and reacts quickly to dry indoor air.

• Aim for 60–80% humidity; below 50% often leads to crisping leaf edges and stalled growth.
• Watch for curling leaves, brown tips, and spider mite outbreaks as common signs of humidity stress.
• Increase humidity with a nearby humidifier, grouped plants, and a pebble tray, rather than misting leaves directly.

This plant needs moist, airy, organic-rich soil that drains quickly yet does not dry out too fast.

• Use a loose, loamy mix of roughly 50% peat or coco coir, 30% compost, and 20% chunky materials such as bark, perlite, or pumice.
• Ensure fast drainage so water runs through in seconds while the mix still holds moisture evenly around the roots.
• Target a slightly acidic to neutral pH of about 6.0–7.0 for Alocasia macrorrhizos 'Borneo Giant'.
• Avoid heavy clay, compacted mixes, or straight garden soil, which reduce aeration and increase the risk of root rot.

This large species can be grown in containers if the pot provides sufficient volume and stability.

• Choose a wide, heavy container to prevent the tall, top-heavy plant from tipping in wind or when soil is moist.
• Select a pot depth that allows thick, tuberous roots to spread vertically without coiling tightly at the base.
• Use a pot material with moderate breathability, such as thick plastic or glazed clay, to slow evaporation while still allowing heat dispersion.

This large aroid benefits from steady nutrition during the warm growing season to support oversized foliage typical of Elephant's Ear.

• Use a balanced, water-soluble fertilizer (around 10-10-10 or 20-20-20) at 1/2 strength every 2–3 weeks in spring and summer.
• In containers, supplement with a slow-release granular fertilizer at the soil surface at the start of the growing season.
• Pause or reduce feeding to 1/4 strength monthly in fall and winter when growth slows or dormancy begins.
• In the ground, incorporate compost or well-rotted manure in spring to improve soil structure and provide gentle, long-lasting nutrients.

Alocasia macrorrhizos 'Borneo Giant' needs light, targeted pruning mainly to keep foliage healthy and the clump tidy.

• Best time for pruning is during active growth in spring and summer, when recovery is fastest.
• Remove yellowing, dead, or mechanically damaged leaves at the base with a clean, sharp knife or bypass pruners.
• Thin out badly crowded stems to improve air flow, which helps limit fungal leaf spots and keeps the plant more balanced in shape.
• Avoid cutting healthy green leaves heavily, as this reduces photosynthesis and can slow overall growth and vigor.

This fast-growing giant often outgrows containers or planting spaces and needs thoughtful repotting or transplanting to stay vigorous.

• Check for roots circling the pot, pushing through drainage holes, or noticeably slowed growth as signs it needs a larger container.
• Plan repotting or outdoor transplanting in mid to late spring, once soil temperatures are warm and frost risk has passed.
• Move up only 1–2 pot sizes, using a rich, well-drained mix; handle the thick roots gently and avoid breaking large rhizomes.
• Water thoroughly after moving, then keep soil evenly moist and provide bright, indirect light for 1–2 weeks to limit transplant shock.

This plant is most reliably propagated by division of its rhizomes rather than from seeds or cuttings.

• Time division for late spring or early summer, when Alocasia macrorrhizos 'Borneo Giant' is entering strong growth.
• Gently unpot or lift the clump and separate offsets with their own roots and at least 1–2 healthy leaves or buds.
• Plant divisions in a warm, humid environment with loose, well-drained, high-organic soil and bright, indirect light.
• Maintain steady moisture without waterlogging and avoid strong direct sun until new growth indicates successful establishment.

This tropical species is frost-sensitive and needs specific winter care in most temperate climates.

• In USDA zones colder than 9, grow in containers and move indoors before temperatures drop below 50°F.
• For in-ground plants in mild climates, apply a 7–10 cm mulch layer over the root zone to insulate rhizomes.
• Keep indoor plants in bright, indirect light at 60–75°F and reduce watering so the soil stays just slightly moist.
• Expect partial dormancy with fewer new leaves; do not force growth with heavy watering or high fertilizer rates.