Planting the bulbs
When to plant -- Your bulbs (technically corms) will sprout in autumn, around late September/October in the Northern hemisphere (early April in the Southern Hemisphere). Until then, store them in a paper bag. Or you may plant them in soil before autumn, if the soil is kept dry until autumn. Either way, store them out of direct sunlight.
Pot size -- Use a pot about 6 inches tall (15 cm) and wide enough so each bulb is about 2 inches (5 cm) from the next one, and from the edge of the pot. The pot needs drainage holes. To keep the bulbs from overheating, it's best to use a clay pot that is light in color.
Soil -- Use a fast draining soil mix, similar to cactus mix. A typical mix is 1 part potting soil to 2 parts coarse horticultural sand or perlite.
Planting the bulb -- If you can't tell which end of the corm is "up", just plant them sideways and they will straighten themselves out as they grow. Bury them 1 inch (2.5 cm) deep. Again, keep the soil dry until autumn. In early October, water the soil lightly until it is slightly moist (not saturated).
The bulbs should begin sprouting within a few weeks of watering them. Once they sprout, move them to a sunny spot. In hot climates, they may need some afternoon shade, otherwise full sun is best throughout winter.
Watering -- Aim to keep the soil evenly moist throughout the growing season. Avoid letting it dry out completely, but also don't keep it soggy. You may use a moisture meter to monitor the soil moisture down at the root level. You can buy this at garden and hardware stores inexpensively. Simply stick the probe in the soil to the level where the roots are.
Climate -- The Starfish Iris does best in mild, frost-free temperatures during its winter growing period. It grows best between 40 and 75 degrees F (4-24°C) from October through April in the Northern hemisphere (April to October in the Southern hemisphere). It can usually handle warmer temperatures provided that nights are cool (below 65°F / 18°C). It probably can tolerate an occasional, light frost, but i recommend protecting it from freezing temperatures.
Lighting -- Mostly-sunny conditions are best throughout the winter & spring growing period. Some afternoon shade might be needed in warmer climates, especially during spring.
Feeding -- This species has relatively low fertilizer requirements, so strong fertilizers should be avoided. Feed twice during the growing season using a slow release (granular or organic) fertilizer.
Dormancy care -- In late spring or summer, the leaves will begin to turn yellow and die back as the bulbs prepare for their summer dormancy. Reduce watering during this time, giving just enough water to keep the soil from drying out completely.
Once the leaves have completely died back, you may remove the bulbs and store them in a paper bag in a cool spot until autumn.. or just leave them in their pot. Again, give just enough water to keep the soil from getting completely dry.
Pests -- None that i'm aware of.
Have fun growing them!
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