Microsorum pustulatum [my-kroh-SOR-um] [pus-tew-LAY-tum] is a fern with bright green, and glossy fronds often found growing on trees.
The name is synonymous with Zealandia pustulata, but many sources haven’t accepted the Zealandia genus.
The plant belongs to the family polypodiaceae and microsoroideae subfamily, which is part of the fern family.
Microsorum pustulatum is native to New Zealand and Australia.
The interesting plant has two common names – kangaroo fern and hound’s tongue.
It is also known by the synonym Microsorum diversifolium.
Another popular Microsorum is the Java fern (Microsorum pteropus)
Microsorum Pustulatum Care
Size and Growth
- Microsorum pustulatum is an epiphytic plant, growing on the surface of other plants.
- It obtains nutrients and moisture from the air, rain, and debris around it.
- The plant spreads through hairy rhizomes, which are often bright green and brown.
- The fronds grow from an erect stem, reaching up to 15″ inches long and 6″ inches wide.
- The glossy fronds have a leathery texture.
- The undersides are covered in spore capsules, allowing the plant to create new growth.
- The shapes of the fronds vary.
- Younger plants often have single strap-like fronds.
- As the plant matures, it may develop fingered fronds.
- The rhizomes produce fast, creeping growth, frequently covering large areas on the ground.
- It may grow over fallen logs or rocks and appear on banks and cliffs.
Flowering
The kangaroo fern doesn’t flower.
It produces round spore cases on the undersides of the leaves.
Light and Temperature
- The plant grows best in the shade or filtered shade.
- It shouldn’t receive direct sunlight.
- If grown as a houseplant, avoid placing it too close to a window.
- Set it along an opposite wall or several feet away from the window.
- The kangaroo fern is suited for outdoor growth in USDA hardiness zones 10 and 11.
- It can’t survive freezing temperatures.
- The ideal temperature range is 70° to 75° degrees Fahrenheit (21° – 24° C) during the spring, summer, and fall.
- During winter, the plant can tolerate temperatures between 60° and 65° degrees Fahrenheit (15° – 18° C).
- In cooler conditions, it can receive a little more sunlight.
Watering and Feeding Microsorum Pustulatum
The soil shouldn’t completely dry between watering.
Check the soil frequently and water when the top 50% has dried out.
Continue adding water until it starts draining from the bottom drainage holes.
Once established, the plant doesn’t need much care.
Water the Microsorum pustulatum when the soil is mostly dry.
Use liquid fertilizer diluted to half strength.
Add the fertilizer once per month throughout the spring and summer.
Soil and Transplanting
Use coarse soil with good drainage.
Succulent potting soil or cactus potting soil amended with the organic matter should provide the ideal base for the plant.
If the roots fill its current pot or basket, repot in the spring.
When transplanting, consider dividing the rhizomes to create new sets of kangaroo fern.
Grooming
Remove dead fronds to allow for new growth.
Use sharp gardening hand pruners and cut the fronds close to the stem.
How to Propagate Microsorum Pustulatum
Propagate the kangaroo fern using spores or rhizome division.
- To divide the rhizomes, dig the soil around the plant.
- Remove the plant and cut the rhizomes using sharp, sterile gardening shears or scissors.
- Each new plant should have several rhizomes and fronds.
- Young plants should receive less water compared to established plants.
- Add just enough water to keep the top of the soil lightly moist.
- After the roots form, new fronds should start to appear.
- When the plant starts to grow new fronds, resume normal plant care techniques.
To propagate using spores, remove a healthy frond from a stem when the spores are mature.
- They should be hairy and plump.
- Place the frond in a plastic bag and allow it to dry.
- When the frond dries, shake the bag to loosen the spores.
- Scatter the spores over a mixture of peat moss and standard soil.
- Use a short pot with drainage holes placed in a saucer.
- Water from below by filling the saucer with water.
- A slime-like coating should eventually appear on the soil.
- After several months, you should start to see small fronds growing from the slime.
- Dig up the young plants and transplant them to separate pots or spots in the garden.
NOTE: I’ve had the best results starting spores in a covered plastic container like a sweater box or a cut down soda bottle.
Microsorum Pustulatum Pest or Disease Problems
Kangaroo fern rarely suffers from pests or disease problems.
It’s safe and easy to cultivate.
While the plant spreads easily through its creeping rhizomes, it’s not considered invasive.
It’s also nontoxic to people and animals.
Chewing on the fronds may cause digestive issues, but the plant has no known toxicity.
Kangaroo fern is remarkably pest-free, especially when cultivated outdoors in the right environment.
- If grown as a houseplant, it may attract the same pests which attack any indoor plant.
- Aphids and whiteflies may appear on the fronds if conditions become too dry.
- If the pests spread, try washing them off with sprays of water from a garden hose.
- Allow the plant to dry thoroughly before attempting to spray the plant again.
- The plant is sensitive to insecticides.
- For severe infestations, create a homemade insecticide using a combination of dish soap and water.
Suggested Kangaroo Fern Uses
Microsorum pustulatum is best cultivated in hanging baskets or large pots.
It’s possible to train it to grow over logs and rocks.
In warm regions, it provides an interesting ground cover for garden beds.