Polymer gel crystals - good or bad?

[Pelvis Popcan]

I've done some searches on the web for polymer gel crystals - you know, those crystals that you can either buy separately or by as a "moisture control" or "smart soil" premix, that are supposed to absorb

100-1000 times their weight in water and make more water and nutrients available to roots.

I can't find ANYTHING negative on the web about them. There are links to tons of studies where they say that adding the crystals is good for plants, some say it's so good it should be ground up, mixed with water into a slurry, and your plant's roots should be dipped in the stuff!

And of course, the labels on the bags all tout how great the crystals are.

However, I did find something interesting in the book, "Ortho's All About Container Gardening," available at most Lowe's / Home Depot type stores (or Amazon). On page 27, the following is written:

"Polymer Gel: Pros and Cons

Water-holding polymer gel has received much attention, but its use is controversial. In isolation, polymer gel crystals can absorb a lot of moisture, expanding up to 100 times their weight in distilled water. In soil, however, ions decrease the water-holding capacity of polymer gel by as much as 85%. Research shows that at the low rates recommended on product labels and offered in some potting mixes, polymer gel is ineffective in increasing the water available to roots. Organic matter is less expensive, so it can be used in potting mix in much greater quantities than polymer gel to hold far more available water. To be effective, polymer gel must be mixed into potting soil at such high volumes that its expense and excessive shrinkage preclude its use."

In searching the web, I can't find anything to corroborate these statements.

I'd be interested in hearing your opinions.

[Dr. Rev. Chuck, M.D. P.A.]

Drip, wick, or (better yet), hydro.

[Pelvis Popcan]

Apples and oranges, IMHO.

Drip, wick, hydro - these are alternatives to top watering. The pot will need watered with both the crystals mixed in or without, the crystals are said to both hold water and act as a wetting medium, so that water is distributed throughout the soil more evenly. And so water is "held" around the roots of the plants nearer the top of the pot.

Of course, that's what they're *supposed* to do.

So, drip - wick - hydro with or without soil that has the crystals mixed in?

[Frank Logullo]

As a chemist, I would tend to believe this. But, still holding up to 15X their weight in water might be helpful. I grow my tomatos in pots with mixtures of potting soil and top soil (cheap stuff) and need to water like crazy. Frank

[Frogleg]

They sure are fun to watch. :-) I think the main (non-chemical science) problems are that they don't make watering unnecessary, just less frequent and they're kind of expensive for large-scale application. I got some years ago, and now, reminded, might add to selected new pottings to assess more carefully. But you still have to remember to water things from time to time. It's a little like (in my mind) fast-rise yeast. All my old recipes (and plant care experiences) are with non-improved systems that I understand. However, I might just re-pot a plant I keep neglecting to water regularly with added cyrstals. That poor sucker can use any help it can get.

[B & J]

It works fine if you mix the recommended amount of crystals with the potting soil and add water before putting the mixture into your containers. Be sure you add enough water and allow the mixture time for complete hydration of the crystals after adding water. That assures you won't have too much material in your pots. I use crystals and like them. :)

John