Dendrobium bigibbum var. schroederianum
Subgenus : -Section : Phalaenanthe
Disclaimer: This article reflects on knowledge I gathered throughout the time and my observation on my own plant based on my growing condition. Your growing area might be different from mine and require different kind of care routine. I hope this article can be used to give an idea on what sort condition that this particular plant prefer under my care.
A common epiphytic Dendrobium species in that being kept in Indonesia, that share common look with Cooktown orchid.
Commonly known by its synonym, Dendrobium phalaenopsis, or local name, anggrek larat.
Comes from Larat Island in Tanimbar archipelago.
An easy species to be kept, make sure it's kept in bright indirect light and dry and porous media.
Charcoal chunks in a clay pot is preferrable for potting in rainy tropic area.
Commonly known as Anggrek Larat in Indonesia, denoting its habitat, Larat Island. It's also portrayed on our 2016 series Rp. 1.000 bill. Just like the bill, this pretty purple bloom is pretty common and affordable in the Indonesian local plant market.
At the beginning, I was very confused with this species and all the literature about it. The root of the confusion lies in the fact that we almost never call them by their scientific name, yet they had several scientific name iterations throughout the time. Now it's known as a variety of Dendrobium bigibbum, and to muddy up the water, these species are often simply called Dendrobium phalaenopsis which is not accepted anymore.
Habitat
It’s commonly known that Dendrobium bigibbum var. schroederianum only can be found on Larat island, an island that’s part of a group of islands called Tanimbar. It’s worth noting that the Kew Science page mentions that its native range includes Lesser Sunda island.
I personally haven’t had the chance to visit Tanimbar nor Larat Island, and the documentation about this species is very few, let alone about its native habitat. Thus, to get a general idea of its native habitat, I tried to find information about the island's condition.
Larat Island is located at the North of Tanimbar Islands. This archipelago is located southeast of Indonesia. It is a remote archipelago surrounded by seas and islands; Arafura Sea on the east, Banda Sea on the northwest, and Timor Sea on the southwest. The islands surrounding the archipelago are Seram Island and Banda Arc at the north, Papua to the east, Australia (Darwin) at the south, and Timor Leste at the west.
Larat Island has a rocky coast with thick vegetation around its shore, and also high cliffs. Checking the topographic map of Larat Island and comparing it to the neighbouring island, Yamdena, it’s clear that the elevation of Larat Island is pretty low, probably max 120-150 meter.
Larat island is part of Wallacea, an area in Indonesia that’s located in between Sunda and Sahul shelves. This means that the area has a unique blend of Asia and Australia flora and fauna.
Larat Island, including other islands on Tanimbar and Banda Sea Islands are part of Banda Sea moist deciduous forest ecoregion. Under tropical monsoon climate, this region has two seasons. Wet season happens under the influence of the west monsoon, while the dry season is caused by the east monsoon. Wet season occurs around December to June, followed by dry season from July to November. As the name suggests, moist deciduous forest is one of the forests that exist there, among dry deciduous forest, evergreen and semi evergreen rain forest.
I can’t find documentation about temperature, humidity and daylight length for Larat Island, what I found is the one for Yamdena Island, which is the neighbouring island. I assume that the climate of both islands should be relatively similar, due to their close proximity. General idea of the yearly temperature and humidity can be checked in this link. In general, the temperature hovers around 27-29 C, yet the highest and lowest recorded temperature can go as far as 42 C and 17 C. Humidity is higher during morning and drops in the evening. In the morning, humidity hovers at 80-92% and drops to 60-70% in the evening.
Description
Growth Cycle
Following sympodial growth pattern, Dendrobium bigibbum var. schroederianum grows a new pseudobulb or more when currently growing pseudobulb is matured. The new pseudobulb pops out from an eye at the base of a matured pseudobulb, forming a light green conical shaped shoot, like a bamboo shoot. Usually, after a month, it will start pushing out roots. Another flush of roots will happen before it’s maturing. It takes about three months for the new pseudobulb to mature.
When it’s reaching its end of growth, it will push out a terminal leaf and start fattening its bulb. If the plant is mature and healthy enough, inflorescences can be expected. Inflorescences will take one to one and a half months to develop and open. If the plant is not mature or healthy enough, it’ll push out new growth instead, and the growth cycle will repeat. Old pseudobulbs will retain their leaves. It will drop older leaves if the leaves are heavily damaged i.e. sunburned, or the plant needs nutrients from the leaves to continue its growth.
My Care Regime
Dendrobium bigibbum var. schroederianum, similar to most hard cane dendrobiums, likes bright indirect light, coarse and fast drying substrate for planting and a warm to hot environment. It likes a lot of water, but the potting media should not stay wet for too long. I found that it reacts well with frequent feeding with a low dose of fertilizer. This way, it grows fast and big, but rather reluctant to flower, or often push out a rather deformed peduncle and pedicels with a cluster of few flowers. As per the time this article is written, I’m planting it in a claypot with wood charcoal media.
I’ve planted my Dendrobium bigibbum var. schroederianum in several ways. I’ll explain those set ups and how it performed.
I received my plant mounted on a piece of coconut shell, the fibrous side facing the roots. The media was bird nest fern roots, sandwiched between the roots and the coconut fiber. I hung the plant on outdoor shelves one meter away from the edge of a canopy. Being mounted, the plant got daily soaking. I usually soak my plants with a solution of synthetic vitamin B1, and auxin. Roots grew well and very dense, but the roots are not long, the tips quickly dried up.
It outgrown the itty bitty mount very quickly, thus I repot it into a plastic net pot with big slits. Despite calling it a repotting, what I actually did was cut the wire hook off and wedged the mount into chunks of large charcoal, I have to note that I didn’t bury the rhizomes or root at all. With this set up, I placed my plant on a floor, on a bright shaded corner outdoors. I allowed it to get rained and get ample air movement. I water the plant every morning unless it’s raining, with the same fertilising regime.
Pot means more space for roots to spread and grow, consequently bigger plant and pseudobulbs. I’d say it enjoyed pot with charcoal a lot more than being mounted. It bloomed for me for the first time.
Its sympodial growth pattern made it reach the lip of the pot pretty fast. I repotted it and removed bird nest ferns that grew like weeds on the substrate. Currently I’m having it potted in an unglazed clay pot with holes around it. Again, despite calling it a repotting, what I did is really just slide the plant and charcoal out of the net pot, plop it into a clay pot, arrange it and fill it with more charcoal. Make sure that you don’t bury the rhizome under charcoal chunks. Since the roots have stuck and tangled the charcoal into one big mass, and charcoal really doesn't get decomposed, there’s no need to remove the old charcoal from the roots.
I’d say it’s the best set up for it so far. The porous surface of the clay pot absorbs excess water and quickly evaporates it. Thus the media is relatively free from pooling water even if it rains heavily. I did observe that new roots that grew after I repotted into a clay pot are longer and much denser than before. As for care and placement, I still give it the same treatment as it was in a net pot.