Gymnocalycium horstii originated in Brazil, Paraguay, Argentina and Uruguay. The stem is thick, spherical and dark green in color. It is covered in prickly spines that curve outwards.
The diameter can reach up to 10 inches as the plant matures. It will typically start offsetting as it grows and meets the right conditions. Large flowers ranging from white to pink appear during the blooming season.
Some plants need shade while others can tolerate full exposure to sunlight, but too much shade will stop the blooming of flowers.
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Gymnocalycium horstii Care Guide
They are grown as houseplants because they are small in size and bloom quite easily. And luckily for everyone, Gymnocalycium horstii is not reported to have any toxic effects.
These plants do not have the trademark cactus spines on their stems or flowers. You will spot some white ones on the body plant but they flatten over time.
This is something to think about when getting indoor plants. Gymnocalycium horstii can be grown near children and curious pets without any risk of toxicity. Just keep them away from the tiny white spines.
They are also hardy plants which means you must keep an eye out for spider mites, mealybugs and white fungus.
Here’s how to grow and care for Gymnocalycium horstii.
These plants like bright sunlight throughout the year but not directly. They like it filtered or indirect sunlight. Leave them in extreme sunlight and you will damage the plant. How do you know that? Well, damaged Gymnocalycium horstii don’t bloom.
These cacti have shallow roots which are sensitive to water. They also have a high tolerance to drought which means over-watering is a real concern. These plants need to be watered only once every week or two in the summer.
If you live in warm regions, you might want to give them more water. But make sure the roots are dry. These plants are extremely prone to root rot. In winter, you can let them go without water for a lot longer than that.
As is the case with other cacti, Gymnocalycium horstii also needs well-drained potting soil that is gritty. You can get commercial mixes but make sure they are meant for cactus plants and succulents.
The Gymnocalycium horstii don’t really need fertilizing except when their rate of growth is too slow. Any fertilizer that is meant for cacti works and must be fed to the plant when the growth season starts. Make sure you dilute it to half before feeding the plant.
They might be cacti but they grow well indoors in indirect light. And they are not great with frost either. So, if the temperature is before 50 degrees Fahrenheit, place them under a glass container and make sure they have enough heat.
How to Propagate Gymnocalycium horstii
Harvesting the seed is the best way to propagate Gymnocalycium horstii. They must be cultivated early in the spring season because they grow faster in warmer seasons. Make sure there is fresh soil mix in the container and place it in a sunny place. Water the seeds enough so that the soil stays moist at all times.
They can also be grown from cuttings of small offsets that must be removed from the plant and dried for a few days. Then, they must be dipped in rooting hormone and planted.