Red Siam Aglaonema Care: Keeping the Red Color Vivid

Overview

Getting a massive pop of neon color in your house usually comes with a catch. If you want the bright pink of a Stromanthe, you have to run a humidifier 24/7. If you want the blazing red of a Croton, you have to bake it in direct sunlight. Enter the Red Siam Aglaonema (Aglaonema 'Siam Aurora').

This cultivar of the classic Chinese Evergreen is an absolute game-changer. It features lance-shaped, dark green leaves that are heavily outlined and veined in brilliant, glowing neon red and pink. The true beauty of this plant, however, is not just its color—it's the fact that it is practically indestructible. It is highly forgiving of missed waterings, doesn't care about humidity, and happily tolerates lower light levels, making it the perfect colorful centerpiece for beginners.

Light Requirements: The Color Tradeoff

Standard green and silver Aglaonemas are famous for surviving in dark, windowless offices for years. The Red Siam, however, has a tradeoff. Because it has less green chlorophyll (due to the massive red borders), it requires more light to survive.

If you place the Red Siam in a dark corner, it won't die immediately, but it will enter a survival state. It will stop producing the beautiful red edges and push out solid green leaves to maximize photosynthesis. To keep the plant brilliantly red, you must place it in bright, indirect light. An east or north-facing window is ideal. Avoid direct, hot afternoon sun, which will scorch the delicate leaves.

Watering: Erring on the Dry Side

The Red Siam Aglaonema has thick, fleshy roots that hold a significant amount of water. This makes it highly tolerant of drought, but incredibly susceptible to root rot if overwatered.

You must allow the top 2 to 3 inches of the potting soil to dry out completely before you water. If you stick your finger into the soil and it feels damp, wait a few more days. When the soil is properly dry, soak the pot thoroughly until water flows out the drainage holes, but ensure it never sits in a saucer of standing water. If the lowest leaves turn a sickly yellow and the stems feel mushy, you are drowning the plant.

Temperature and Humidity

As a tropical understory plant, it requires warm indoor temperatures between 65°F and 85°F (18°C - 29°C). It is highly sensitive to cold drafts; temperatures below 60°F (15°C) can cause permanent cellular damage and leaf drop. Fortunately, it is completely unfazed by dry indoor air and does not require a humidifier.

Soil and Potting

Because the roots rot easily, a fast-draining potting mix is essential. Standard indoor potting soil should be amended with 30% perlite to ensure excess water drains away rapidly. It is a very slow grower and prefers to be slightly root-bound, so it rarely needs to be repotted.

The Flowers

If your Red Siam is perfectly happy, it may suddenly produce a flower during the summer. The flower looks like a small, pale green Peace Lily (a spathe and spadix). While exciting, the flower is not very pretty and drains a massive amount of energy from the plant. It is highly recommended to use sterile scissors to cut the flower off at the base as soon as it appears, forcing the plant to redirect that energy back into growing its spectacular red leaves.

Toxicity

Like all plants in the Araceae family, the Aglaonema contains insoluble calcium oxalate crystals. If chewed by cats, dogs, or children, these microscopic crystals embed in the soft tissues of the mouth and throat, causing severe burning, swelling, drooling, and vomiting. Keep the plant safely out of reach.