I’m Ferb Vu, and if you’ve ever stumbled upon the Rainbow Fern – Calochlaena Dubia, you probably had the same reaction I did: “What is this feathery beauty, and why don’t I already have ten of them?” Over time, I’ve grown it, studied it, and compared it to many other ferns and shade-loving plants in my garden. Let me walk you through the most common questions I get about it.
What Is Rainbow Fern – Calochlaena Dubia?
The Rainbow Fern, also called Soft Bracken or Calochlaena Dubia, is a lush, evergreen fern native to the Eastern Australian rainforests, particularly New South Wales and Queensland. Its fine-textured fronds, often bronze-tinted when young, give off a soft, rainbow-like glow in the right light—hence the name.
In my garden, it adds a wild, woodland feel, especially under dappled shade. It spreads softly without becoming invasive and offers excellent groundcover for moist, shaded garden beds.
Is Calochlaena Dubia Invasive?
Not in my experience. Unlike Bracken Fern (Pteridium esculentum), which can get aggressive, Calochlaena Dubia grows in well-mannered clumps. It colonizes politely, if you will. It forms tidy mounds and doesn’t choke out neighboring plants.
Still, I wouldn’t ignore it entirely. In rich, damp soil, especially in warm climates like USDA Zones 9–11, it spreads faster. I just trim the edges once a year. Easy.
How Do I Care for Rainbow Fern?
Rainbow Fern loves the same kind of care I give to my Blechnum Silver Lady and Maidenhair Ferns.
Here’s my personal checklist:
- Light: Dappled shade or bright indirect light. Full sun crisps the fronds.
- Soil: Rich, loamy, and well-drained. I mix in leaf mold and compost.
- Water: Consistent moisture. Don’t let it dry out.
- Humidity: High. Perfect for subtropical gardens or greenhouses.
- Pruning: Snip old fronds at the base to keep it lush.
Fertilizing isn’t necessary, but I use a diluted seaweed solution every spring.
How Does Rainbow Fern Compare to Boston Fern?
I get this one a lot.
- Boston Fern (Nephrolepis exaltata) is a popular houseplant, often grown in hanging baskets.
- Rainbow Fern prefers the ground and thrives outdoors in temperate to subtropical climates.
Boston Fern is more compact and dense. Rainbow Fern is airy and elegant. Boston needs very high humidity indoors, while Calochlaena Dubia is happier outdoors in the garden. I’ve grown both, but Rainbow Fern wins for texture and adaptability.
Can I Grow It Indoors?
Technically, yes. But here’s the thing—I’ve tried, and it can work if you give it the right microclimate.
- Think bright bathroom with skylight.
- Group it with other ferns for a humidity boost.
- Mist it daily.
- Avoid drafts and heating vents.
Even then, it’s not as tolerant of dry indoor air as, say, Bird’s Nest Fern (Asplenium nidus). I mostly keep mine outdoors under tree canopies or in covered patios.
Is Calochlaena Dubia Deer Resistant?
Yes, and this is one of my favorite perks. Deer, rabbits, and even wallabies (if you’re in Australia) tend to avoid it. I grow it near more vulnerable shade plants like Hostas, and it acts like a soft shield.
What Plants Pair Well with Rainbow Fern?
I’ve paired mine with:
- Clivia Miniata – bright orange blooms contrast with its soft green.
- Hellebores – for early-season blooms.
- Tiarella (Foamflower) – delicate texture match.
- Blechnum Ferns – similar moisture needs but different frond shape.
- Native Groundcovers like Viola hederacea or Dichondra repens.
This combination creates a textured understory that feels like a rainforest floor.
How Do I Propagate It?
Simple: division.
I divide my mature clumps in early spring or after the last frost. Use a sharp spade and separate the rhizomes. Replant immediately and keep them moist. I’ve had over 90% success this way. Seeds? Technically possible, but I’ve never bothered. Division is faster and cleaner.
Does It Change Color?
Not rainbow like a chameleon, but the young fronds emerge in shades of bronze, copper, or even pinkish red. That’s the magic. In soft light, the overlapping colors give it a shimmering, iridescent look—like a rainbow. Hence the name.
As it matures, the fronds turn bright green, creating a lush, feathery carpet. It doesn’t really change color like Autumn Fern (Dryopteris erythrosora), but the emerging flushes are show-stopping.
Final Thoughts: Why I Love Calochlaena Dubia
I’ve grown dozens of ferns, but Rainbow Fern—Calochlaena Dubia—has a special place. It’s:
- Low maintenance
- Visually striking
- Non-invasive
- Wildlife-friendly
- And a perfect fern for adding movement, texture, and a sense of place to a shaded garden.
It’s not just a plant; it’s a vibe.
If i die, water my plants!
