Herself's Houston Garden

Conservation through cultivation

Hack your garden using water crystals






Too dry to grow your favorite plant here? Try Water Storing Crystals.

July 9th
I tripped across these by accident last week. One user said they turned to mush in the heat, another source said they use them to grow palms in the desert. One person claims they super heated the soil in her outdoor potted plants? Other people claim to have used them for years with no problems.

I have a half dozen Angel’s Trumpets along the driveway, none get enough water, the top two keep dying from thirst. I dug up the top one and mixed in two tablespoons of the water crystals, dug a circle around the second and mixed in a tablespoon of crystals, then watered both.

These are supposed to be non-toxic. Some gardeners grow their vegetables with soil mixed with the crystals. Other people were concerned about the break down product, acrylamide, a known neurotoxin. Cheaper crystals are more likely to contain acrylamide.

1 tablespoon per square foot is the recommended rate. Use them dry, mix with the soil, I used fertilized water to soak them after putting the soil back in the hole. The deeper you plant the crystals the better, heat and light break down the crystals and deeper water sources encourage plants to send their roots down deeper.

Use too many and you may find your plant uprooted after a downpour, several growers reported problems with the crystals expanding too much and pushing up plants or breaking pots.

Will they conserve water? Not really, the plant needs the amount of water it needs, what they will do is hold the water so you can go longer between waterings. My guess is you’ll lose less water to evaporation and run off.

Several companies make them, formulas vary. Some are polyacrylamide hydrogels (dissolve, last 3-4 months), some are cross-linked (not dissolvable, last 3-5 years) both seem to use potassium. The crystals are in the cross-linked group.

They were developed in the 1960s to help grow plants in the desert, absorb fluid for cleanup, for disposable diapers, depending on who you ask.



July 12, 2104
The ground is wetter around the plants with the water crystals nearby, otherwise I’m not seeing any difference.

On a forum a member claimed the water crystals super heated her container plants. I had this experience with some carnivorous terrariums that are in a large south west facing window. I don’t think I’d use them in containers which are place in a sunny area.


So far mixing the water crystals with the soil seems to be helping the plants. But it’s still too early to know for sure. They expand more with rain water than with tap water so leave more room for them outside.

The water crystals when mixed with soil and planted under new plants in areas that are often dry have helped. The plants are staying green longer and not wilting and the soil feels damper around the plants that have crystals mixed into the soil

Mixed in with potted plants they didn’t work so well, they tended to clump and block air from the roots and the pots were much hotter than the pots with out the crystals.


March 2017

These crystals might be good for short term design stuff but in every case the plants who had water crystals mixed in with the soil died. That’s too bad, they look cool and it’s a great idea. Maybe a future version of them will work?


Pros:
Polymer moisture crystals: magic for your garden

Cons:
The myth of hydrogels
A greenhouse experiment finds water-sorbing polymers do not conserve water

See also:
Carnivorous plants and water crystals
Orchids and water crystals