Blue oil fern are one of the epiphytic and lithophytic plants native to Southeast Asia. It is found in Thailand, Southern China, and Vietnam. It is most well-known for its extraordinary blue leaves; the Microsorum thailandicum (steerei) originates from the humid, shaded jungles in limestone areas, where the blue leaves are the adaptation to absorb more sunlight in the low-light understory conditions.
Regarding the care required, I’ve found them fairly easy to develop. But, they’re very slow and require constant care over a long time to appear their best. So, it would help if you remembered to maintain them with water for several weeks at an interval (or they’ll begin dropping leaves or completely die).
If you’ve ever cultivated Paphiopedilum Slipper Orchids will appreciate the endurance required to care for slow-growing species such as those. Changes in growth are measured in years and months rather than weeks or days, and you may not be as satisfied because they’re mostly ordinary plastic plants instead of flourishing and growing like the Philodendron. This plant is suitable for those who can easily follow a regular schedule, aren’t easily distracted, and provide daily consistency for years.
Unstable circumstances (especially the watering frequency) can hinder this plant’s growth, but I’ll discuss the details of culture and care below. If you love blue plants, and that’s what’s drawn you to blue ferns, I suggest you look into Begonia pavonina.
Ultimate Guide For Blue Oil Fern Care, Microsorum Thailandicum
My 2 blue oil ferns for around two years now, and although they’ve grown slow, they’re doing great. It’s important to note that nearly every fern I’ve tried to cultivate has died within a couple of months, except for a few weedy ferns that appeared in a terrarium. I’d say this is an accomplishment. I didn’t even care for the plants, the ones I had.
The two ferns I have are in one pot. They produce a lot of fresh leaves from spring to summer when the temperatures are warm (23-28C); however, during winter (when temperatures average between 18-22C), they don’t expand at all. Initially, I believed this was due to low-quality water (I used to use tap water). However, I’ve had several seasons to observe the changes in the yearly wintertime stall. It’s important to note that, even when the ferns haven’t been actively growing, I regularly water them and keep their roots in good condition.
The Microsorum Ferns I have potted in a typical “terrestrial orchid mix” that I use for paphipedilums and the Phragmipedium orchids. It’s made of pumic at a ratio of approximately 1-to-1. Suppose you don’t have an access point to pumice substitute large-chunk perlite. The ferns’ roots are planted into the mix and then covered with sphagnum moss at the pot’s top and tucked in near the bottom of the plant.
The top-dressing of sphagnum mounds ensures that humidity is maintained when new leaves and roots start. Consider this: if your plants were to grow solely on leca, bark, or pumice, the top layer (and the base of your plant) can become very dry, which could hinder the growth of weak new growth points.
All care sheets state, “high to very high humidity is required,” as with all plants in tropical rainforests; more humidity would be ideal, and if you can help, please consider it. But, the humidity at which I plant my ferns is typically low and less than 50%rH. I believe that with constant humidity at the roots and localized humidity (provided by the sphagnum-moss), you can cultivate this fern with no issues with humidity. If the roots don’t become bone dry, however, if they dry out in dry conditions, this could kill the fern.
The process of watering
Potting media must be kept constantly humid. I’ll usually allow my pot to sit in a tray with a small amount of water for three days per week. Now it’s time to let the roots grow through the bottom and extend to the water’s surface. I water my ferns at least every week and run an entire pot of water across the.
The thick orchid potting mix that I previously mentioned ensures airflow throughout your root area (which helps prevent rot), So it’s best to use the less dense mix (like Peatmoss, which is pure). It’s possible that you won’t be able to water frequently or as heavily as you would like, and it’s best not to leave the pot in water for as long as I suggested.
Opt for pure water (under 50ppms). While this species is usually grown on limestone rock, and I thought my alkaline tap water might be okay, they didn’t like tap water and sweated. It’s possible that it was due to the main’s chlorine level or temperature fluctuations. However, it’s in line with the feedback of other growers on this subject. Pure water (like RO or distilled water, also known as rainwater) is the most effective.
In general, for ferns of all kinds, the mineral content in my water from the faucet (~250ppm TDS) is excessive, and after 6 months of no activity, I switched to RO bottled (reverse the osmosis) water. Following the change, growth began to follow.
Pure water is typically required to help plants with sensitive roots that may not be well-adapted to soils with a lot of minerals. I also utilize this RO water to treat carnivore plants such as Nepenthes and Butterworts. After trying both, I strongly suggest that you use pure water because of the difference I’ve observed in the growth.
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Fertilizers and nutrients
We’ve already covered that blue oil ferns are slow to develop, but this indicates staying clear of feeding them excessively. For epiphytic orchids, fertilizer made from orchids is perfect. I also use tiny amounts of organic fertilizer, such as rock dust and bloodmeal, but only a tiny pinch twice yearly during growth.
Since they are native to limestone regions, The blue oil ferns could have a greater reliance on calcium carbonate. If your fern appears to be struggling, and you’re providing the other options, you can consider adding a tiny quantity of oyster shells into the potting media. You can purchase this from an animal supply store. If you’re in a pinch, you can use a small amount of crushed eggshell in place or an oyster shell.
Disclaimer: This is not a verified or tested suggestion as I sometimes flush my potting medium with tap water (to provide tiny amounts of calcium), but I do not include oyster shells. This is standard practice for terrestrial orchids or the lithophytic orchids of similar habitats, which rely on higher calcium levels.
Low-to-moderate. My plant is in a grow light with LEDs with the timer 12h in the day and 12h at night. They are getting about 12w for each square foot of area, which does not include the extra illumination they receive from the east-facing window. I’ve considered this zone “moderately bright” compared to many growers’ conditions. It is possible to grow them at a rate of 8 watts per square foot.
However, it’s best to try to verify. The report states that although Blue oil fern is a fan of lower levels of light from the understory, it can take on more bright “sub-understory” light levels, meaning they could be able to grow higher in trees and may be able to handle more light than most species of ferns and tropical plants. It’s also reported that “some growers have had excellent success maintaining the [blue] color in very bright light.”
To be clear, this does not mean direct sun, and you should be wary of anything with more than 40% filtered sunlight.
General principles for the standard cultivation of Blue Oil Fern, Microsorum Thailandicum
Inquiring about other growers’ websites There are also other common threads of data I’ve gathered:
- They develop slowly
- They require consistent moisture at the root and high humidity and appear to thrive in the presence of water (making them the perfect choice for semi-hydro systems, self-watering, or drip-irrigation systems).
- They don’t require a lot of fertilizer.
- They’re fairly robust and easy to cultivate, accepting extremes of moderate or even low light, wetness, and short periods of dryness and variations in humidity.
Important information about growing and sustaining Blue Oil Fern from the Exotic Rainforest
One cultivator, Jay Vaninni, notes that he has numerous mature blue oil ferns alongside his collection of Neoregelia high-light bromeliads and other species in his collection that are in deep shade. Both collections “look just fine.” Vaninni adds, “[the blue oil ferns] look considerably better when watered with reverse osmosis or rainwater and fertilized with very dilute fish emulsion and kelp extract.”
“We have many of the blue ferns in our garden [attached to limestone. you might want to plant them in a moderately well-lit container or terrarium with a couple of inches of gravel at the bottom. Add water up to 50% of the length of the gravel] to ensure that the gravel remains moist.
This will ensure a high level of humidity within the container. Then, the ferns can be grown on a limestone rock containing the sphagnum moss or on a substrate directly on top of the gravel. Then Mist the ferns frequently and keep the root system stuffed with moist orchid moss until you’re certain the roots are fixed. We usually feed the ferns with a very light fertilizer for orchids.
Blue Oil Fern Species Name: Is it Microsorum Thailandicum or steerei?
It’s a constant occurrence that each time I try to write a blog post about the care of a plant, the taxonomy monster swoops into the picture and makes a basic matter exponentially more complex (and boring), so why is it that ferns are different? There is a possibility of finding “Blue Oil Ferns” listed as either Microsorum steerei or Microsorum Thailandicum. Some people think that both M. steerei and “M. Steerii” are synonyms for M. Thailandicum. However, both species are recognized as species with accepted names.
Whether or whether the blue oil fern is just M. Thailandicum, I’m not sure. However, my ferns (acquired in 2000) were identified as “Microsorum steerei.” If M. Thailandicum truly is an alias for M. steerei, then technically, M. steerei would be the correct name since it was registered first in 1933, before M. Thailandicum was registered in 2001. It’s possible that the original “Microsorum steerei” is just an entirely different species, which is why some think the earlier name is an abbreviation for Microsorum Thailandicum.
Whatever the reason, I’m unable to find it since I’ve been unable to establish clarity (from reliable sources) regarding whether both species are Blue Oil ferns. Based on their habitat and range, the above care guidelines will still apply, assuming that there are two species. If you know more precise details on the taxonomy of Blue Oil Fern, please let me know. Blue Oil Fern, write me a message through Instagram, and we’ll talk about it so that I can improve this page for other species.
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