Water retaining crystals – yay or nay?

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? 


  1. I’ve never used them, but have considered it. But if there is a possibility they are carcinogenic? I’ll just stick to what I’ve been doing…watering my plants!

    • Gimmicks are usually not all they’re cracked up to be – I’m rather concerned about that potential health risk. I definitely need to break out my watering can more often! 🙂

  2. Hi Sheryl. I used them in hanging baskets years and years ago. Never bothered again as I didn’t notice any difference, and they were expensive back then! Perhaps they’ve improved them now though…

    • I do wonder if the starch-based ones are as good as they say – apparently they’re far superior to the polyacrylamide ones and you can go nearly a week extra between waterings. But, you’re right, they’re expensive and I don’t know if it’s really worth purchasing them to conduct a test.

  3. Sheryl, I know a dedicated gardener who uses the crystals. I don’t use them because I came across some of the same things that you did. Also, I’m not in charge of house plants, which tend to die off pretty regularly here. Not that I’m blaming anyone.

    • LOL love your comment about the houseplants! 🙂 Yes, now that I’ve read up a bit more, I’m a tad concerned about using the crystals I have (which are the polyacrylamide ones). I’m not certain the extension of time between waterings is substantial, anyway – and if there is a potential health risk, it’s better to stop using them.

  4. I actually used a product in my pots and hangers this year. They are sealed in an envelope. When watered it turned into a pillow. I found that took up a bit too much room in the hangers but all in all, green thumbs up because they really worked well.

    • Good to hear that they worked for you, in outdoor containers! I agree that they sometimes puff up a bit too much and use up considerable space in the containers. I always have to remember to adjust for the size of the pot. I wonder if you had the type made out of starch?

      • mmmmmm, not sure. I bought them at Greenland Garden Center near Edmonton. The envelopes were completely flat and without reading the details I assumed they stayed that way…LOL. Yes, only really good in a bigger pot.

  5. I have lined my hanging pots with pampers diapers and then put soil on top and the flowers needed far less watering, especially good in the hot weather. SuzAnne.

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