Planting the tuber
Container size -- Use a container about 3 times as wide as the tuber. The containers needs drainage holes.
Soil -- Use a well draining mix. I use a mix of 1 part coco fiber to 1 part perlite. An alternate mix is 2 parts quality potting soil to 1 part perlite or coarse horticultural sand. In heavy rainfall areas, use a bit extra perlite or sand.
Planting the tuber -- Fill your container to within 3 inches (7 cm) of the top, place the tuber sideways on it, and cover with 2 inches (5 cm) of soil. Don't compress the soil. Water just enough so that the soil is moist throughout, but not soggy.
Keep the pot at around room temperature until it sprouts. It should sprout within about 4 to 8 weeks, but might take up to 3 months, especially at cooler temperatures. Keep the soil lightly moist until it sprouts, but not fully saturated. Once it sprouts, you may start increasing the waterings.
Light -- Give it bright light after it sprouts, but not strong sun. This Calla doesn't need as much direct sun as most Callas. It grows fine in bright shade with some filtered sunlight. If exposed to more sun, it will require more watering and feeding. Protect it from hot afternoon sun.
Watering -- This Calla likes consistently moist soil when it's not dormant. During warmer or sunnier weather, make sure the soil doesn't dry out. It reportedly can be grown in boggy conditions, but i have not tried this.
Climate -- The Hercules Calla prefers mild temperatures. In warmer climates, shade it during the warmest part of the day, and don't plant it where heat can accumulate, like near a sunny wall. The plant can go dormant during summer, and if it does, the tuber (or entire pot) may be brought indoors during this time.
The tubers are winter hardy to Zone 8 (20°F/-6°C) if planted deep. But since the plant prefers to grow throughout winter, it's best to grow it in a pot and bring it indoors before frost strikes.
Repotting -- Repot each year to a larger container (or into the ground in suitable areas). Avoid disturbing the root ball when you repot. Each time you repot, bury it 1-2 inches (3-5 cm) deeper. Eventually, after several years, it will need a large pot, such as 5-10 gallons (20-40 liters) or more.
Winter strategies -- If you bring it indoors over the winter, try to keep some or most of the leaves intact, if possible. Removing too many leaves may delay flowering.
Fertilizing -- While your plant is actively growing, feed every 2-3 months with an all-purpose fertilizer that contains micronutrients.
It's normal for an older leaf to occasionally turn yellow, but if it seems excessive, it could be from not enough nitrogen fertilizer, but more likely it's from overly dry soil down in the root zone.
Bugs to watch for -- Spider mites, Aphids, snails/slugs.
before using stronger remedies, since some may harm the plant.
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