Blechnum gibbum [BLEK-num, GIB-bum] is a hard fern belonging to the family Blechnaceae.
Native to Pacific Islands, Fiji, and New Caledonia, Blechnum gibbum grows as a small tree in tropical and subtropical climates.
It is also widely grown fern houseplant.
You may hear it by its common names including:
- Silver Lady
- Silver Lady Fern
- Dwarf Tree Fern
Blechnum Gibbum Care
Size & Growth
As mentioned above, this is a dwarf tree type fern growing up to 3’ – 4’ feet in height and features symmetrical fronds rosette over a slender, black, scaly trunk. Some refer to them as dwarf tree ferns.
It grows comparatively faster than most other tree fern types known for their slow growth. It is seen growing as an understory plant in forested areas.
The fronds of the plants are comprised of bright green-colored, and slightly drooping leaflets are of two types – spore-bearing and sterile.
Flowering and Fragrance
Being a fern, it does not produce flowers.
Light & Temperature
Blechnum prefers bright light with partial shade and a slightly warmer temperature.
However, it cannot survive in strong direct sun.
The plant requires high humidity during its growth period starting from mid-spring through late fall.
To maintain the humidity level, place the pot over a tray filled with moist pebbles throughout the warm season.
While the plant may regrow even if it gets frozen due to exposure to frost, it is not considered a frost tolerant plant and should be protected from it.
Watering and Feeding
Just like most other ferns, Silver Lady grows best in moist soils.
Water it frequently during the warmer months to keep the potting mixture moist, which will ensure proper growth.
Slightly reduce watering when the temperature falls below 54° degrees Fahrenheit (12° C) and let the topmost layer of potting soil dry out between waterings.
Make sure not to overwater because it will cause root rot.
Avoid watering from overhead as the foliage can get damaged if it stays wet for an extended time.
Water the plant once a week in winter. Water more frequently during summer.
Another important thing to know is Blechnum is intolerant of lime, so do not use hard water on the plant.
If you live in an area where hard water is supplied, it’s recommended to use purified water or rainwater for the plant.
However, if it isn’t possible either, then add a few drops of lemon juice to the water before giving it to the silver lady plant.
Apply a half-strength liquid fertilizer once a month during the period of active growth.
When grown indoors, add a slow release fertilizer once in spring and summer.
Soil & Transplanting
Blechnum gibbum thrives in compost-enriched, moist, and slightly acidic well-draining soil.
It’s recommended for USA hardiness zone 10. Mulch the surface of the soil to keep the roots moist and cool.
As a container plant, repot into a bigger pot when the roots begin to come out on the surface of the pot; about once every two years.
Use leaf mold and soil-based potting mixture in equal quantities for repotting.
Early spring is the best time to repot.
Grooming and Maintenance
Blechnum gibbum is an easy-to-grow and low maintenance plant.
Just remove the browning fronds by trimming them off from the base as they diminish the aesthetic appeal of the plant.
Spring is the best time for rejuvenation pruning or major trimming.
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How To Propagate Blechnum Silver Lady Fern
Blechnum is propagated through spores and takes between 1 – 3 months to germinate.
- Sow the spores thinly in damp compost and cover the pot with a cling-film.
- Do not water and place the pot in a warm and well-lit area, such as a window sill.
- Maintain a temperature above 25° degrees Fahrenheit (-4° C) centigrade to ensure proper germination.
Rarely, the plant produces basal offsets, cut them off from the parent and plant separately.
Tree Fern Silver Lady Pest or Diseases
Wiping the leaves with a slightly damp cloth helps keep these pests away from the plant.
But, even if it gets affected by them, it’s easily treated with insecticides.
Overwatering and lack of ventilation can cause the fronds to turn brown or bronze.
The plant can only recover from water damage if treated immediately.
Uses for Dwarf Tree Fern
Blechnum is a beautiful addition to gardens, patios, pergolas, terraces, and courtyards.
Whether grown in the ground or pots, silver lady serves as a fantastic focal plant.
The plant’s root system is also used to produce substrate for growing orchids.