Yep, the lemon and mandarin orange trees are going well.
No idea which is which yet lol. We may well try to Bonsai them.
But, there was a disaster about a week ago, when one of our cats attempted to climb out of the closed window !
It knocked the whole lot onto the ground and we lost 'Number 6'. That was the little tree, that was, well, number 6 of the seeds to pop up under the LED's. It literally was lost. I picked all the soil up and replanted them and such, but No. 6 was nowhere to be found. Got a feeling that I know where the cat stood !
Found another cherry tomato seed stuck in me gob today on eating a salad...so planted him in the same pot as the other

No chemicals of any type will be used, in common with all planting here. Rainwater for watering, collected in gallon jugs.
The only additions are grass mulch and tree leaves from the back yard.
Lidmotor had an experiment going with 'Phylis' some years back. he had a magnesium firestarter and a piece of copper in a pot, with a phyllidedrum (sp?) plant. Blocking oscillator attached. When the LED would begin to fade off, he would water the plant.
There are concerns of metals though, in my opinion and some plants will be hardier than others.
I would suggest a well built uA constant light oscillator, powered from multiple metals rods, in a section of soil sectioned off by a piece of plastic. If the separator is just below the top soil line, then the plant water should still be able to cross through, but any galvanics induced metals seepage will be contained.
The big problem, one of which i've only ever partially sorted, is that of summing galvanic cells that share an electrolyte - as in, all the metal pieces in the same ground. Only 1 negative needs to be in the ground, all the oscillators can connect to that same piece, but have their own positive metal. All oscillators will output individually like that, but not summed...and I need to return to that problem

If outdoor space is easy to work with, then you could do worse than mounting things on a sun facing wall (I have no idea where the sun is in Australia lol). Especially if your wall stays relatively warm in winter, from house heat.
Some plexi, a pop bottle or similar, covering small plants, will help with watering them in dry times.
As to indoors....I grew the trees in my bedroom !