It's fairly soon to be writing a review of these self watering trays. I have only monitored the windowsill style. I have set up one large tray with mostly ferns. The pots they are in may not be suitable as they have a small lip on the base of the pots to allow free drainage in a normal drip tray and so the compost in the pot is slightly above the level of the capillary matting to allow capillary action into the compost. The large tray however will provide some constant humidity to the ferns.
The windowsill trays I have set up with Streptocarpus and they are potted up plug plants in 9cm pots with a flat base that allows the compost to touch the wet matting. I was cautious filling the reservoir to avoid soaking my carpet as well so there may have been room to squeeze a bit more water in. I restricted it to three pots per windowsill tray. The reservoir has been used up after 11 days and on day 12 the matting is starting to dry out. The pots , however , show with a moisture meter to be fully moist as if recently watered , so I am confident that the Sterptocarpus would be fine after two weeks. They are placed on an East facing windowsill to get morning sun but avoid midday and afternoon sun. I have to rotate the pots to avoid some of the large arching leaves from touching the wet matting which would cause the ends to rot. All six pots are flowering well in this situation. The matting , once wetted , can be stretched slightly so that folds flatten out and it just looks like a flat black base inside the green tray. I am not sure how advisable it is to keep Streptocarpus constantly moist in this way. It is tempting to do so because once the capilliary action is flowing it just requires regular refilling of the reservoir without the need to water the pots. The pots do need to be turned occaisionally to avoid the plants rooting themselves in the matting , some vigorous plants may be more prone to that.
The weather this spring has been fairly cool , so evaporation not so great as it may be in the summer. If we have anything like the heat wave of 2022 I will move these trays to a shadier North facing room and sacrifice some of the light in favour of keeping the plants hydrated for the holiday. The trays used with suitable pots do appear to offer a simple and effective solution to holiday watering and beyond that as a regular method to keep moisture loving plants reliably watered. I am certainly pleased with the purchase so far.
