Caring for a fern cactus (also known as Rhipsalis) is a bit unique because it blends characteristics of both ferns and cacti. Here are the key care tips:

1. Light

• Indirect light: Fern cacti thrive in bright, indirect light. Direct sunlight can scorch their delicate stems, so a spot near a window with filtered light is ideal.
• Low light: They can tolerate low light, but they won’t grow as vigorously or bloom in these conditions.

2. Watering

• Watering frequency: Water your fern cactus when the top 1-2 inches of soil feels dry. They don’t need to be watered as often as traditional cacti but do need more moisture than most cacti. Avoid letting the soil stay soggy, as this can lead to root rot.
• Humidity: Since they are native to tropical environments, fern cacti appreciate some humidity. If your home is dry, especially in winter, you can mist them lightly or place them on a tray with pebbles and water to increase humidity.

3. Temperature

• Moderate temps: They prefer temperatures between 60-80°F and don’t tolerate extreme cold well, so keep them away from drafts or chilly windows in the winter.
• Avoid frost: Frost can damage or kill a fern cactus, so ensure it's kept in a warm environment.

4. Soil

• Well-draining soil: A mix designed for cacti or succulents works well. Fern cacti like their roots to be well-drained to prevent moisture buildup around the roots.

5. Fertilizing

• During the growing season (spring and summer): Feed your fern cactus with a balanced, diluted liquid fertilizer every 4-6 weeks to encourage healthy growth.
• Fall and winter: Reduce or stop fertilizing when the plant is dormant, as it doesn't need extra nutrients during this time.

6. Repotting

• Every 1-2 years: Repot your fern cactus when it outgrows its pot, or if the soil becomes compacted. Choose a pot that is just slightly larger than the current one to avoid over-watering issues.

7. Common Problems

• Leggy growth: If your fern cactus is stretching or becoming leggy, it might not be getting enough light. Move it to a brighter location to encourage fuller growth.
• Yellowing leaves: This can be a sign of overwatering or root rot. Ensure the pot has good drainage and only water when the soil is dry.

With a little attention to lighting, watering, and humidity, your fern cactus should thrive and add a touch of unique beauty to your plant collection!