One of the most fascinating aspects of hermetospheres is to see how plant communities develop over years in a confined space – with only minimal intervention. The picture below shows the current state of one of my first containers. How it became what it is today is this story.
One of my first containers ever was inspired by the flora of Myanmar. The hermetosphere was started on 30 October 2021. The substrate consists of four layers, from bottom to top: lava granules 2-4 mm (3 cm high), dried sphagnum moss (<1 cm high), lava sand 1-2 mm (2 cm high), lava sand 0.63-1 mm (2 cm high). A lava rock placed vertically at the periphery of the substrate was meant to give the landscape some structure. In my early attempts, I had a tendency to use far too much substrate. For this container, half the amount or a depth of 4-5 cm would be more than sufficient. Planted were: two shoots of the terrestrial wood sorrell family herb Biophytum sensitivum, 8 and 4 cm high, respectively; two shoots of the epiphytic growing ‘miniature shrub’ Ficus punctata; a rhizome section of the epiphytic growing fern Pyrrosia nummulariifolia; and four leaved pseudobulbs of the epiphytic growing orchid Bulbophyllum oblongum.
The following two photo series show the development of the hermetosphere over more than 2½ years from two different perspectives.
What follows are the main observations and interventions over time.
- Nutrient supply: As the substrate is not expected to release significant amounts of nutrients in short and medium term, I added liquid fertilizer to the system on two occasions in the total equivalent of approximately 300 cm2 of leaf area.
- Nutrient recycling: Biophytum and Pyrrosia grew so vigorously or too tall for the container, respectively, that I removed excess biomass on three occasions, dried and chopped it and gave it back into the system.
- ‘Mould’: By mid-January 2022, fungal mycelium had covered large parts of the substrate surface; in order to reduce moisture, the lid of the container was opened on several occasions to let condensed water evaporate; most of the mycelium vanished and did not reappear.
- Biophytum sensitivum: By mid-December 2021, the larger of the two shoots had flowered, produced plenty of seeds and scattered them all over the container; the seeds germinated in large numbers, and the second generation forms a large part of the current vegetation without flowering again; the two initial shots grew too tall for the container, got cut off (cf. ‘nutrient recycling’), and the remaining stems sprouted again.
- Pyrrosia nummulariifolia: When the fern threatened to overgrow the Ficus, 40-50 cm of rhizome were removed (cf. ‘nutrient recycling’) on one occasion.
- Ficus punctata: In an early phase, the Ficus replaced large parts of its foliage, but then grew slowly and steadily without flowering.
- Bulbophyllum oblongum: One by one, the leaves and pseudobulbs have turned brown and black and died; none of them flowered.
Will the Ficus survive? Will it ever flower? Will the young Biophytum plants produce a third generation? There will be plenty to discover in the next years.
Hermetospheres 