Tree ferns, with their majestic lacy fronds, are perfect for adding a touch of tropical elegance to the garden.
With their lush, dramatic fronds and sturdy trunks, tree ferns can transform any outdoor space into an oasis, even in the middle of the city.
Whether you’re nurturing an Australian tree fern (Cyathea cooperi) or a hardy Tasmanian tree fern (Dicksonia antarctica), these beauties are surprisingly adaptable.
In this post, I’ll share some tips and tricks on how to grow and care for tree ferns, ensuring they thrive for years to come.
Fossil records suggest that tree ferns first appeared on Earth during the late Jurassic period, approximately 180 million years ago.
This means that tree ferns have been thriving on our planet since the time of the dinosaurs.
Australian tree ferns are majestic plants that can add a touch of the tropics to any garden. With their large, graceful fronds and tropical appearance, these ferns make a striking statement in outdoor spaces. However, in order to help your Australian tree fern thrive, you need to plant it in the proper soil
Choosing the right type of soil is crucial for growing healthy Australian tree ferns. The soil needs to meet the specific needs of these plants in terms of drainage, nutrients and pH level. In this article we’ll walk through the key factors to consider when selecting the ideal soil for your Australian tree fern.
An Overview of Australian Tree Ferns
Australian tree ferns, also known by their botanical name Cyathea cooperi, are native to the tropical rainforests of Australia and New Zealand. These fast-growing ferns can reach towering heights of up to 50 feet in their natural habitat.
Although Australian tree ferns thrive in tropical environments they can also be grown successfully in more temperate climates when provided with the right care. These plants prefer warm temperatures, high humidity and moist, well-draining soil.
When given the proper growing conditions, Australian tree ferns reward gardeners with huge, dramatically shaped fronds that unfurl from a trunk covered in dark brown scales. Their lush, graceful foliage creates a striking vertical accent in the garden.
Key Factors for Australian Tree Fern Soil
To enable your Australian tree fern to flourish, focus on providing soil that offers these key characteristics:
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Rich in organic matter – Australian tree ferns need nutrient-rich, organic soil to support lush growth. Aim for a mix containing compost, peat moss, leaf mold, rotted manure, and other organic materials.
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Well-draining – Good drainage is crucial to prevent root rot. Incorporate perlite, coarse sand, or small gravel into the soil to improve drainage.
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Slightly acidic pH – These ferns prefer a pH between 5.5 and 6.5. Test soil pH before planting.
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Moisture-retentive – Tree ferns require consistently moist (but not soggy) soil. The mix should hold water reasonably well.
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Nutrient-rich – Regular fertilization is important for Australian tree ferns. Use a slow-release fertilizer or apply liquid fertilizer monthly.
When you choose or create an soil mix with these characteristics, you’ll provide the ideal foundation for your Australian tree fern to thrive.
Recommended Soil Components
Here are some of the best ingredients to use in creating the perfect soil for your Australian tree fern:
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High-quality potting soil – Use a potting mix formulated for ferns and tropical plants as a base for your custom blend. Look for mixes with high organic matter content.
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Peat moss – Peat moss introduces organic material while helping to retain moisture and create an acidic pH.
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Perlite or coarse sand – Incorporating perlite or sand improves drainage to keep soil from compacting and becoming waterlogged.
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Compost – Compost adds nutrient-rich organic matter and beneficial microorganisms. Use compost designed for potting mixes, not garden compost.
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Leaf mold – The decayed leaves in leaf mold offer an acidifying, moisture-retentive amendment for fern soil.
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Well-rotted manure – Small amounts of aged manure enhance nutrition levels. Avoid using fresh manure, which can burn plant roots.
Creating the Ideal Soil Mix
A suitable soil blend for your Australian tree fern can be created by mixing equal parts high-quality potting soil, peat moss, and perlite or coarse sand.
To further enrich nutrition, add a couple handfuls of compost and leaf mold per gallon of soil mix. You can also incorporate a small amount of well-rotted manure or slow-release fertilizer granules when planting.
Always test the pH of your final mix before planting your fern. Adjust as needed by adding sulfur to lower pH or lime to raise pH. Proper pH is crucial for nutrients to be available to the plant.
Caring for Australian Tree Fern Soil
After planting your Australian tree fern in the ideal soil, be sure to maintain optimal conditions to keep its soil healthy:
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Water thoroughly to keep soil consistently moist but not saturated. Allow the top inch or two of soil to dry out between waterings.
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Apply organic mulch like pine straw or bark around the base of the fern. Mulch helps retain soil moisture and adds organic matter as it decomposes.
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Fertilize regularly during the growing season with a balanced liquid fertilizer or time-release fertilizer spikes.
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Check pH periodically and adjust as needed to maintain a slightly acidic level.
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Repot annually in fresh soil mix to provide nutrients. Prune roots if root-bound.
Healthy soil is the key to growing vibrant Australian tree ferns. By understanding these plants’ soil requirements and crafting a customized soil blend, you can create the perfect foundation for your fern to thrive. Pay close attention to drainage, organic matter, and pH when selecting components for an ideal potting mix. With a nurturing growing medium, your Australian tree fern will reward you with lush, dramatic foliage.
Why Winter Protection is Important
Tree ferns are susceptible to frost and freezing temperatures, which can damage the fronds, trunk, and crown:
Frost Damage:
Frost can burn the delicate fronds, turning them brown and crispy.
Crown Protection:
The crown, where new fronds emerge, is particularly vulnerable and needs to be shielded from extreme cold.
Trunk Insulation:
The trunk, which stores moisture and nutrients, needs insulation to prevent freezing and cracking.
Insulating the trunk is a crucial step in protecting tree ferns during winter:
Wrap the Trunk:
Use horticultural fleece, burlap, or straw to wrap the trunk from the base to just below the crown.
This insulation helps keep the trunk warm and prevents frost damage.
Here is the insulation I recommend:
Secure the Wrapping:
Tie the wrapping material securely but not too tightly to allow some airflow and prevent moisture buildup, which can lead to rot.
Check Regularly:
Periodically check the wrapping to ensure it remains in place and adjust as necessary, especially after heavy winds or storms.
The crown of the tree fern, where new fronds emerge, is the most critical area to protect:
Cover the Crown:
Use a thick layer of straw, horticultural fleece, or a frost protection blanket to cover the crown.
This layer acts as a barrier against frost and cold winds.
Allow Airflow:
Ensure the covering allows some airflow to prevent mold and mildew from developing.
Avoid using plastic, which can trap moisture.
Remove Covering in Spring:
Once the threat of frost has passed, remove the covering to allow the new fronds to emerge and grow without obstruction.
For areas with severe winters, consider additional protective measures:
Mini Greenhouses:
For smaller tree ferns or those in pots, consider using a mini greenhouse or cold frame to provide extra protection.
These structures can help maintain a warmer microclimate around the plant.
Mulching:
Apply a thick layer of mulch around the base of the tree fern to insulate the roots and soil.
Organic mulch like bark chips, straw, or leaf litter works well.
Watering During Winter:
Reduce watering during the winter months, but do not let the soil dry out completely.
Tree ferns still need some moisture, especially during dry, cold periods.
Move Potted Ferns Indoors:
If your tree ferns are in pots, move them to a sheltered location such as a greenhouse, conservatory, or even indoors.
Ensure they receive adequate light and humidity in their new location.
Do tree ferns like sun or shade?
Tree ferns generally prefer shaded or partially shaded areas, which mimic their natural habitats under the canopy of larger trees in tropical and subtropical forests.
Too much direct sunlight can scorch their fronds, causing them to turn brown and dry out.
While some species can tolerate more light, providing them with dappled shade ensures they stay healthy and vibrant.
If you live in a hotter climate, consider planting tree ferns in an area that receives morning sun but is shaded during the hottest part of the day.
Alternatively, using shade cloth or positioning taller plants nearby can help create the ideal environment.
A guide for choosing and planting ferns | Garden Design and Inspiration | Gardening Australia
FAQ
What kind of soil do Australian tree ferns like?
What is the best soil mix for ferns?
What is the best soil for Tasmanian tree fern?
How do you repot an Australian tree fern?
Do Australian tree ferns need the right soil?
Here are some tips to ensure your Australian tree fern has the right soil: Soil Type: Australian tree ferns prefer a soil mixture that is rich in organic matter, well-draining, and slightly acidic.
Can you grow an Australian tree fern indoors?
Yes, you can grow an Australian tree fern indoors, provided it gets enough indirect sunlight and humidity. It’s important to ensure that the plant is in a large enough pot to accommodate its growth and that it has a well-draining soil mix.
Are Australian tree ferns fast growing?
In the wild, Australian tree fern is the fastest-growing of the tree ferns. As a potted plant, it grows not quite as much but it is still a fast grower with an annual growth rate of up to three feet. Are Australian tree ferns hardy? The tree fern is a tropical plant that is only hardy in USDA hardiness zones 9 thru 11.
Can Australian tree ferns grow in shade?
Australian tree ferns prefer bright, indirect light, but they can also tolerate partial shade. Direct sunlight can scorch the fronds, so it is best to avoid placing the plant in direct sunlight. If the plant is not receiving enough light, the fronds may become yellow or brown and drop off.