Use of Mineral Oil to avoid Evaporation
I was given 2 Cyperus alternifolius (umbrella papyraus) or similar cuttings by my mother. They are effectively my first ever plants - I do not yet have green thumbs.
I am growing them reasonably successfully in 2 jam jars with a decent amount of soil, and I have then been keeping them well watered with approx 3-4 cm of standing water above the soil level. They both now have 1 new growth stem, which are both opening into umbrellas.
The problem: I need to leave them without supervision for 1 month. I think 4cm of water might just last them that long, but I do not want them to dry out. If I carefully add a thin layer of mineral oil to the top of the top of the standing water, this will prevent a significant amount of water evaporation. However - Will it damage the plants? I've seen that mineral oil is used as a pesticide without damaging plants, but this scenario might be a bit different.
All thoughts and ideas are welcome.