I have a confession to make.
Really, I should be ashamed of myself. It’s time I got it out in the open, however:
I’m not very good at remembering to water my houseplants. It’s not that I mean to forget…it just sometimes happens. I like to pretend it’s because I’m doing everything within my power to prevent mould and other nasty humidity-related issues, but really, it’s just because I’m always on the go and certain things get kind of shuffled to the wayside.
Yep, now I’ve admitted it. Please don’t judge me too harshly! 😉
It’s a good thing I have mostly African violets, which like to dry out between waterings. In an attempt to alleviate the pain and suffering of my poor beleaguered plants, I’ve occasionally used water retaining crystals (aka hydrogels) in my potting soil. For the most part, though, I haven’t really had to significantly change my watering schedule for plants with water retaining crystals in the soil versus those without; the extension of time between waterings seems to be a couple of days, perhaps three or four if I’m lucky. I’ve never tried out the crystals in my outdoor containers, so I’m not sure if they would make a difference in hanging baskets or planters. I’ve also never used commercial premixed potting soil that contains hydrogels.
Here’s the thing: it seems that there is a bit of a controversy regarding water retaining crystals. Many garden experts do not recommend their use, calling them gimmicks and citing their ineffectiveness. (Plus, potting mixes containing the crystals are more expensive than those without!). And, even more damaging: I came across an article this past week which suggests that the common type of crystals made from polyacrylamide may actually be carcinogenic! Oh boy, that’s not what I want in the soil for my houseplants…and definitely not in the potting mixes I’m growing food crops in.
There are alternatives to the polyacrylamide crystals (besides actually watering on a regular basis!). The ones made of starch may actually be better at retaining water, and they are considerably safer. I’m not certain how many studies have been done about all of this, and there is bound to be some continued debate.
Weigh in! Have you ever used water retaining crystals – or would you ever use them – in your potting soil?