Water crystals for plants

How to Grow Plants with Hydrogel Crystals

September 19th, 2018 Fantastic Team Greenthumb Guide Post Views: 2,850

While gardening is a hobby that can bring a lot of positivity to your life, sometimes you’re too busy and too tired to take care of all the plants around your house. Hiring a professional gardener will do the trick, but for small, household plants water beads may be the solution that you’re looking for.

Perfect for all types of plants, using hydrogel crystals allows for slow release of water when the plant needs it. This can help reduce root rot and other problems related with overwatering or not enough watering.

What are water beads?

The so-called water beads are little granules created from water absorbent polymer. They can be used as a soil additive or on their own (if the plants can be grown in water only). Because they release water slowly in the soil, water jelly crystals are good for the planet as well.

When shopping for water beads you can see them labelled as hydrogel crystals, water jelly crystals, granules and gel crystals. While it’s the same thing, we advise you take five minutes to read the description of the product or to consult with a salesman.

How much water can crystals hold?

Water granules are pretty small when dry but when put in water they will grow a couple times their original size. It takes some time for the little gel crystals to absorb the water, they will grow.

А teaspoon of dry water beads is enough for a two-litre pot. If you put in already hydrated granules in the pot two cups are more than enough.

How much water beads you should use?

There is no limit on how much water beads you should use. The amount must be adjusted according to the plant and the size of the pot. The general rule is one to four (e.g. one cup of water beads to four cups of soil).

How to hydrate water granules?

Before using them in gardening you will have to hydrate the dry water granules. Depending on the brand of granules you’ve bought there are different amounts of water that they can retain.

Place the granules in a laver and cover them with warm water (cold water works as well, it just takes longer). While most instructions will say to leave the granules to soak for three to four hours, we advise you to leave them overnight. That way you’ll be sure they’ve absorbed as much water as the gel can hold.

After you’ve drained any excess water (if there’s any) the granules are ready for use.

How to grow plants with water beads?

Hydrogel crystals can be used for growing plants both as a water retainer in the soil and on their own for growing plants that can grow in water only.

If you’re adding water beads to an already soil-planted plant with developed roots follow the next steps:

Step 1: Remove the plant from the pot.
Gently remove any soil that is on the roots of the plant. Be careful as not to tear and damage the rooting of the plant.

Step 2: Place the water beads and the potting mix in the pot.
Keep in mind that potting soil allows for free flow of the water. Place the granules on the lower half of the pot in order for them to always hydrate properly.

Step 3: Put the plant in.
Once you’ve put the granules in the pot it’s time to place the plant. Make sure the roots have contact with the granules, as they will have to grow into the hydrogel beads.

Step 4: Top off with potting soil.
When you’ve put the plant in the pot add the rest of the potting soil. And that’s it! Keep an eye on your plant to see how often it would need to be watered.

Fertilising the water beads

If you’re growing plants in water beads only (without the use of soil) you will have to apply plant fertiliser to keep it healthy as water cannot provide the needed minerals for the plant to grow.

Most plants are doing well when fertilised once a week, but make sure to keep an eye on the plant and adjust the rate of fertilising as needed.

What indoor plants can grow in gel crystals?

Any pot plant can be grown with water beads, and any plant that can grow in water only should be able to thrive in water granules. Feel free to experiment with all types of plants!

How long water beads last?

This is strongly dependant on the type of gel crystals you’re using. Of course some higher end crystals will last longer than others. Generally water jelly granules will be good for around four to five years before needing replacement.


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Frequently Asked Questions

Q – Can I place candles into the water beads?
A – Water beads work great with candles and floral arrangements.

Q – Can I use with my live house plants?
A – Suggested plants include arrowroot, bamboo, Chinese evergreen, dragon plant, dracaena, palms, spider plants, dieffenbachia, and philodendrons. DO NOT USE with cactus, succulents or orchids.

Q – How do I dispose of unwanted water beads?
A – To dispose of unwanted beads simply pour the them into flower beds, gardens or mix into soil. The gel beads are a great additive for potting and garden soils. Water beads are a non-toxic polymer substance that will not harm plants, grass or soil.
CAUTION! Water beads are extremely slippery when spilled. Never flush or pour beads down the drain, swelling could possibly clog drain pipes.

Q – How many beads will a package of the polymer make?
A – Add a package of the dry beads to a 1 quart bottle of water.
Let it stand for about four hours (overnight is great).
The beads will swell up and increase their weight by approximately 50 times.
Next, use a sieve to strain off any surplus water.
Now you have a large bowl or vase of sparkling water beads. Add candles, flowers or some plants, finished!
You will notice that even an ordinary glass turns into a small wonder at the touch of your hands.
Q – How long will the crystals last?
A – Length of life for decorative purposes (because of exposure to light) is approximately 1-2 years. If mixed in soil, it serves for about 7-9 years as a source for moisture retention. Since they are colored throghout they do not fade like some of the lessor quality beads available. If they start to shirnk, it is simply a loss of hydration and all that you will need to do is add water.

Q – Is it safe for kids to use?
A – Water-Gel Crystals is a polymer gel powder and is non-toxic, ecologically neutral, it breaks down after its useful working life to water, carbon dioxide (CO2) and nitrogen.

Although non-toxic it should never be consumed or taken internally in either its granule or its gelatinous forms, it should never be used by children without constant adult supervision.

Q – How many colors of Water Beads are available?
A – Eleven individual colors. All colors of our aqua beads are available in a dry form.

Q – Will Water Beads stain my clothing, furniture, or carpet?
A – No. Aqua Water Beads are colorfast. This means that, when the gems dehydrate, the color stays with them. They will not stain other items, nor will they discolor water.

5 Water Retention Methods for Organic Growers

Even if you don’t live in a drought-prone area, water retention is advantageous for any growing space. Vegetables require copious amounts of water to grow to their ideal eating size, and even in humid climates where moisture is plentiful farms must use surprising amounts of water for irrigation to achieve ideal results.

No matter where you live and grow, there are steps you can take to increase your garden or farm’s capacity for water retention. Ultimately, these management techniques will help you save both resources and time – and your plants will thank you, too. The following are some basic steps you can take to increase water retention.

Till Less.

Good Heart Farmstead in Worcester, VT uses permanent raised beds for their production, avoiding the use of heavy machinery to till their fields. Each bed must be prepared by broadfork before planting. Photo courtesy of Good Heart Farmstead.

Water retention is directly related to the porous space in a soil’s structure: the more porous the soil, the more capacity it has to retain water. Tilling facilitates lots of temporary porous space in the top layer of soil, but also decimates any soil structure that was in place prior to tilling. Because tilling is achieved with heavy equipment, this repeated compaction actually leads to structural breakdown of soils resulting in a highly dense base soil layer topped by loose soil with no structure – thus, when heavy rains occur, water is more likely to runoff and result in erosion, nutrient loss, flooding, pollution, and, of course, less retained water for future potential drought conditions.

According to the Natural Water Retention Measures project put together by the Environment Directorate General of the European Commission, “Intensive tillage can disturb the soil structure, thus . . . decreasing water retention capacity.” On the other end of the spectrum, “No-till farming (also called zero tillage or direct drilling) is a way of growing crops or pasture from year to year without disturbing the soil through tillage. No-till is an agricultural technique which increases the amount of water that infiltrates into the soil and increases organic matter retention and cycling of nutrients in the soil. The most powerful benefit of no-tillage is improvement in soil biological fertility, making soils more resilient.”

Many growers choose “low-till” production methods, which involve some precise and timely tillage in combination with cultivation to suppress weed pressure. In these cases, soil disturbance for the purposes of cultivation can be done thoughtfully to avoid compromising the soil structure. Shallow, gentle cultivation of row crops, whether manual or mechanical, can successfully eliminate weed pressure while maintaining healthy soil structure and water retention capacity.

On a commercial scale, decreasing your tillage may be achieved by incorporating some no-till or low-till practices. Careful planning and dialing in the timing of your tillage can also help you decrease the number of times you must till to achieve ideal soil conditions. On a small scale for home gardeners or market gardeners, tillage may be eliminated all together by using innovative tools designed for the small scale like a broadfork or a tilther.

Apply Compost.

Well managed compost piles at Vermont Compost Company in Montpelier, Vermont. Photo courtesy of Vermont Compost Company.

In addition to boosting overall fertility and organic matter in your soils, compost itself has an impressive water holding capacity as compared to topsoil. However, because no two composts are created equal, Michigan State University Extension has put together an article that focuses on how to choose composts that increase the soil’s water holding capacity. Before applying any amendment to your soil, it is important to know your key nutrient levels to be able to determine what kind and how much to apply. Just like any other soil amendment, there is such a thing as too much compost.

Check out our blog post on how to master the art of soil nutrients to get a sense of how to balance intuition with science to create an optimal soil nutrient plan, including how to choose annual amendments and incorporate soil building practices.

Increase Your Soils’ Organic Matter.

In 2015, the Natural Resources Defense Council delved into the claim that a “1 percent increase in soil organic matter helps soil hold 20,000 gallons more water per acre” and found that yes, it checks out. Adding organic matter to your soil will help improve its overall structure, giving it healthy porosity and the ability to not only filter water more effectively during periods of heavy rain, but also retain more moisture for plants to access during droughts.

For a crash course in building soil organic matter, check out one of our previous blog posts on the subject.

Consider How and When You Irrigate.

Thoughtful irrigation can go a long way in maximizing your use of this essential resource. The best way to get water directly to the plants’ roots is to use drip irrigation lines that literally drip water onto the soil at the base of the plant. This technique minimizes evaporation and requires less water overall since every drop is going directly into the plants’ roots. Overhead irrigation (i.e. sprinklers) can be appropriate in some instances, like watering in a newly broadcast cover crop – however, overhead irrigation should never be used during the hottest hours of the day, since much of the water will evaporate into the air before it even reaches the soil. Because of the risk of evaporation, all irrigation – even drip irrigation – is best applied in the early morning or evening.

Minimize Bare Soil.

The High Mowing trials field uses annual rye in between beds of peppers and eggplant to minimize the amount of bare soil between their crops. Here, Paul and Taylor are standing on the pathways of annual rye which are mowed periodically for maintenance.

When soil is exposed to the sun, the moisture held within the soil will evaporate. If your plants are close enough to each other to throw shade on the areas of bare soil between them, the area of exposed soil can be reduced, saving you water and resulting in fewer weeds. However, when attempting to optimize plant spacing keep in mind that many cash crop plants like tomatoes, peppers and eggplant enjoy some space and need airflow to grow without risk of disease. To retain moisture in the soil between plants that need wide spacing, techniques include using a weed barrier like plastic mulch, landscape fabric, or a biodegradable alternative. Alternatively, sowing dwarf clover or another ground cover that won’t grow tall and compete with the vegetable plant will reduce areas of exposed soil while minimizing weeds at the same time. This is called under-sowing and can help with water retention; before utilizing under-sowing techniques, research the nutrient needs of both your vegetable plant and the ground cover plant to ensure they will not be directly competing with one another for nutrients.

Additional Resources

Natural Water Retention Measures: http://nwrm.eu/measure/no-till-agriculture

Rodale Institute’s Rainfall Simulator to Compare Soil Health: https://rodaleinstitute.org/rainfall-simulator-compares-soil-health/

Science Advances’ Study on Organic Agriculture: http://advances.sciencemag.org/content/3/3/e1602638

. . . and The Ecologist’s Review of the Study: https://theecologist.org/2017/mar/23/we-need-more-organic-farming

Soil Wetting Agents and Gels

SERIES 19 | Episode 16

Gardeners with pot plants, or a sandy garden, are likely to have experienced water repellent or hydrophobic soils. Soils become hydrophobic when they are dry for extended periods – particularly when the dryness is combined with a high organic content.

But these days there are many soil wetting agents on the market intended to help soil absorb water. According to soil scientist, Dr Peter May, there is a simple experiment people can undertake at home to see whether they have hydrophobic soil.

“Take some dry soil and place it in a dish. Make a well in the top and then pour on some water. If the soil is hydrophobic, the water will pool on top. In contrast when you wet soil that is not hydrophobic, the water is quickly absorbed,” he said.

The simplest way to improve water take up by hydrophobic soils is to use a soil wetting agent. “We believe that what happens in some soils when organic matter breaks down is that it leaves a waxy coating on the soil particles. Wetting agents are like detergents. They overcome that waxing coating and allow water to penetrate into the pore spaces between,” Peter said.

“Most potting mixes, if they become dry, will also become water repellent,” he said.

This means that when people say that their plants need watering every day in summer, it might just be the way they are applying water, and the mix isn’t taking up moisture.

“It is certainly possible. I think using wetting agents in pots or containers in summer is a good idea,” Peter said.

Another different product on the market, designed to help gardeners improve the water holding capacity of their soil, is a water-storing granule or gel. These are small crystals of polymers that are designed to absorb up to four hundred times their weight in water.

“A spoonful of crystals, which is about what you’d put into a pot if you were mixing it in potting mix, will absorb about a litre of water if left overnight,” Peter said.

He said the crystals did not save water. “But they increase the water holding capacity of the soil. This means that more water is held for plant use, and that also means plants can go for longer between watering. It will not change the amount of water that a plant uses, but it will last longer between drinks,” Peter said.

The crystals don’t help with water uptake in hydrophobic soils. “That’s a completely different property. The crystals increase the water holding capacity of the soil. But the soil wetting agents overcome hydrophobic soil. It’s important to sort out which problem you have got in the garden and specifically treat it,” Peter said.

To sum up what Peter has discovered.

  • Gardeners with water repellent soil should use a soil wetting agent. It will help with water absorption, particularly if you have sandy soil or pots that are filled with potting mix.
  • Remember if you want to use a water storing gel, remember, it will eventually dry out. You might get an extra day or two between waterings, but beware of products saying they will save you water, because there is nothing to suggest that they actually have a water conservation value.
  • And finally, remember to differentiate between the two products and choose the product that’s suitable for your purpose and your soil.

This is an article from I’ve Always Wondered, a series where readers send in questions they’d like an expert to answer. Send your question to [email protected]

Are water crystals bad for the environment? –Terry Gilmour

This is an excellent question, and something an environmentally conscious gardener might wonder. With changing rainfall patterns, drought and an increasing average temperature in Australia many people are looking for ways to save water in their garden, and adding water crystals to your soil appears to be a good solution. But what do we really know about water crystals and are they bad for the environment?

Well, you can put your mind at ease: water crystals are not bad for the environment. In fact, in other forms they are actually used to help protect the environment.

What are water crystals?

Water crystals are tiny super-absorbent polymers (a long chain that’s made up of identical repeating molecules), about the size of a sugar crystal. They are added to potting mix or added to soil in a garden bed to increase the water holding capacity of the soil.

Water crystals act like a sponge, binding water molecules with the molecule chains in the crystals (with what’s technically known as ). This makes the crystal swell, creating a three-dimensional gel network up to 300 times its original size, absorbing water and nutrients.

Read more: Not all community gardens are environmental equals

Over 5-6 years water crystals slowly degrade, releasing the absorbed water into the root zone of the plant and wetting the soil.

While many water crystals are marketed as water-saving, and many people use them to drought-proof their plants, it’s really important to know that these water crystals don’t actually conserve water. The plants still use the same amount of water, but instead of the water flowing through to the bottom of the pot and into the saucer and evaporating, or through to the bottom of the garden bed, the water crystals hold onto the water in the root zone of the plant. It makes for a more efficient use of the water in the soil.

Gardeners are not always able to frequently water their plants on hot summer days.

Cross-linked vs linear polymers

To understand where the environmental concerns come from, we have to get a little technical.

The most common type of water crystal on the market is a cross-linked polyacrylamide. Cross-linked polyacrylamides are water absorbent but not water soluble. One of their best-known uses is in disposable nappies.

The environmental concern regarding water crystals comes from people confusing these cross-linked polyacrylamides with non-cross-linked polyacrylamide used by industry. While they are commonly described in the same way, they have a different chemical bonding and properties.

Read more: How your garden could help stop your city flooding

Non-cross-linked (linear) polyacrylamide is water-soluble. It is currently used in Australian agriculture for improving soil and to help control erosion. It also plays an integral role in aiding flocculation as part of the sewage treatment process.

A 1997 study found when non-cross linked polyacrylamide degrades it creates acrylamide, a suspected carcinogen and neurotoxin.

Obviously this would be very concerning if it also affected water crystals! Acrylamide could leach into the soil and water and be taken up by plants, entering the human food chain. However there’s no proof cross-linked polyacrylamides – which are the water crystals you’d find in a gardening store – behave like this.

It is not clear if water crystals have a negative impact on Australia’s rivers and streams.

It is also worth noting that further studies, including one published in 2008, found a very small amount (less than 0.5 parts per billion) of acrylamide was released into the environment, which does not cause any environmental concern.

You may also worry water crystals could impact aquatic life if they found their way into rivers and streams. The good news is there’s no reported toxicity or impact on aquatic life from commercially available water crystals (results are more mixed for the water soluble non-cross-linked polyacrylamide, with some studies finding little impact and others showing no toxicity.

Read more: Are common garden chemicals a health risk?

The other good news is water crystals do not accumulate in the soil or water over the long term. The use of water crystals has no adverse impact on soil microbe populations, which we need for a good healthy soil. If used as directed there is no risk to human health (however, it is always good practice to wear gloves while handling any chemical product).

So environmentally conscious gardeners don’t need to worry about water crystals. They’re great for people who don’t have time to water their pot plants every day in summer. Remember, these crystals do not save water but increase the water holding capacity of the soil, so you still need to water your plants regularly – especially on hot days!

Water Jelly Crystals

How Does It Work

A polymer is a very long chain that’s made up of identical, repeating molecules – they’re the “links” in the chain. Think of these links as tiny sponges waiting to connect with water molecules. In the absence of water, the polymer chain is very tightly twisted and piled up on itself so the water connection points are tightly buried inside the nugget. When water is available, the molecular links on the outside of the nugget grab it and hold on through simple cross-link bonding. The more water is available, the more the polymer has to unwind to get it. Each link gets larger as it hooks up to more and more water. The chain begins to swell on the outside surface and that allows more water to get farther into the polymer to available link points. Water is cross-linked farther in and the polymer expands to make room for it. If enough water is available, this bonding and swelling continues until there are no more available places to collect water. Absorption stops but water that’s linked to the polymer has expanded it to about 300 times it’s original weight and it’s not tightly twisted at all. The crystal is now about 98% water and 2% polymer. That’s a lot of water!

Polymers are very common and you see and use them everyday: silk, wool, nylon, cotton, cellulose, proteins, rubber, PVC, epoxy materials, silicone, hair conditioner, paint, polystyrene, adhesives, gelatin, Silly Putty®, polyester, Kevlar®, CDs, eyeglasses, Teflon®, and the list goes on and on!

Why should you wash your hands before handling the crystals? Goobers and germs! Since the crystal is mostly water, it “washes” your hands as you handle it and the dirt it removes has no where to go – neither do the germs and other microscopic nasties from your hands. This build up can lead to dirty and smelly crystals that are no fun for anyone. Eventually, this oily concoction can cause a reduction in the number of places on the polymer that can hook to water. That means a loss of absorption and less water taken up. Besides, it makes the crystals appear cloudy and dull.

Take It Further

Distilled Water – It’s recommended that distilled water be used to soak the nuggets if possible. Distilled water is usually easy to obtain and not very expensive. It’s about $1 (USD) per gallon at grocery stores and pharmacies. Tap water is OK to use but sometimes, purifying it for people changes how it gets absorbed by the polymer. Distilled water is like rain water and has very little stuff in it but… water. Minerals, chemicals, and other dissolved materials that can change how the polymer bonds with it are removed by distilling. The crystals can be larger as a result.

Disappearing Crystals – The hydrated crystals can “vanish” if you know the secret. Fill a clear container with plain water and dump four or five of your largest crystals into it. They vanish but they’re in there! Since they have very nearly the same index of refraction as that of the water around them (they’re 98% water), light passes straight through them and the water so you can’t see them. If you look very carefully, you can barely see the edges of each crystal where light is bent slightly as it passes through the polymer. Check out Vanishing Jelly Marbles for more ideas.

Rainbow Test Tube – Here’s where colored crystals get into the mix and you combine your science lab with some seriously creative art. Find the details at the Rainbow Test Tube site.

Science Fair Connection

Just Water? – You may be wondering if the polymer can absorb anything other than water. To find out, test any of these liquids in place of the water: tomato juice, orange juice, vegetable oil, milk, soda water, rainwater (or melted snow), hot water, sugar water, salt water, etc. Keep track of your discoveries and you’re on your way to a science fair project.

Cold Crystals – Place a zipper-lock bag of the hydrated polymer in the freezer. Examine the bag of polymer after 12 hours. Here’s a test: compare the length of chilling time and the temperatures reached for frozen crystals to a similar amount of water ice. Maybe you could you use frozen crystals in place of crushed ice the next time you need an ice bag.

Polymer Plants – Check out the activity found at Gardening with Water Jelly Crystals. Grow grass seeds, radishes, beans, or other fast-germinating plants in a half-and-half mixture of hydrated polymer and potting soil. Compare by growing the same kind of seeds you planted in the soil/polymer mixture in just plain soil and compare the growth at two day intervals for one or two weeks. This sounds like another great science fair project! How well do seeds germinate and grow in a cup of hydrated polymer without soil? Test it — you might be surprised!

Safety Information

Since this is a science activity, keep the crystals away from your mouth, ears, eyes, and nose, as usual. However, Water Jelly Crystals (a cross-linked polyacrylamide copolymer gel) are considered not to be a health hazard. They’re non-toxic, safe to handle, and safe for use around pets and young children. They’re NOT to be eaten and can be a choking hazard if used carelessly. Don’t dispose of the crystals (either wet or dry) down the drain as they will certainly clog the pipe. Just toss them into the trash – BUT – remember why they were made!

They’re designed to be environmentally beneficial. These crystals are intended to be used with plants, so when you’re finished using them for discoveries, you have two good options:

  1. Simply bury clear, hydrated crystals in a planter box or garden. They dry out as plants use the water they hold and then rehydrate when water is present in the soil again. They’ll support plant growth for about six years.
  2. Let hydrated crystals (clear or colored) completely dry out on a cookie sheet. They shrink back to their original size and can be stored and then rehydrated many times.

Water Storage Crystals

Water crystals – this has got to be one of the hottest topics at the moment… and I’ll give it to you straight.. I don’t use them. Ever. I have never found it necessary, as my soil is so chock full of organic matter that it remains nice and damp all the time. There is a plethora of products on the market, proclaiming to “store” water in the soil.

I myself have a few concerns about some products on the market at the moment, particularly polymer based products. You know the stuff I’m talking about… the little “jelly” looking crystals that can absorb hundreds of times their weight in water and can last for years. The insides of baby nappies are essentially the exact same product that is utilised in many water crystals! They are a polymer based product (a petrochemical as we all know), and is, in fact a copolymer of polyacrylamide (a big name that spells bad news!). I have significant issues with the overuse of polyacrylamide in the garden, one because it is a petrochemical (not very sustainable, and slightly toxic), but it gets worse.

Putting it simply, polyacrylamide is a polymer formed from acrylamide subunits that can also be readily cross-linked. Handle this stuff with caution… and think carefully about using it in the garden, especially near edible plants. Some research indicates that polyacrylamide can degrade under normal environmental conditions, releasing acrylamide, a known nerve toxin. That’s not really ideal, and I reckon it’s unnecessary!

Polymer based products need water to perform, and some research has also suggested that polymer based water products may compete with the plant for water if allowed to dry out. Also, a whole pile of this stuff is manufactured in China and shipped to Australia, pretty unsustainable emissions-wise if you ask me. The other issue I have with polymer based watering products is that they are highly unpredictable, and the rate of moisture can be significantly altered by high temperatures and other factors, which pretty well defeats the purpose!

What I reckon people need to be aware of is how they place these products if they are going to use them, especially for the establishment of trees. We all know that roots “seek out water” and this is no exception with solid water or water storage crystals. If placed incorrectly, there is a real possibility of roots all heading off in one direction to where the water is, creating a “lopsided” root system, which isn’t a problem early on, but will be as the tree grows. Lopsided roots + wind + damp soil = bad news.

There are some products available that are fairly natural, about 98% water with 2% natural vegetable gum to hold it all together. It’s not affected by temperature, and won’t over water as it ceases dispersing when the surrounding soil is wet. I think these are pretty good when attempting large scale plant establishment, especially trees within a landscape. Just be aware that some of these products are also manufactured overseas, which gives them some negative points in the whole sustainable thing!

It must be remembered that these are irrigation supplements, not total irrigation solutions. If you must use this stuff, don’t rely on it to do the hard work for you, and for goodness sake follow the instructions on the container… overdoing it will lead to plants literally “popping out of the ground”! The best water storage aid? Good compost, good aged animal manures, and good soil management.


Dry polymer crystals on the left contrasted with same crystals after 130 ml of water have been added.

As a result of the drought in California, various products have been suggested to promote water conservation, including commercially produced water-sorbing polymers that can absorb hundreds of times their weight in water. The claim is that incorporating these polyacrylamide polymer granules in the soil results in increased retention of large quantities of water that become available for plant growth.

The difference between amounts of water retained by treated and untreated soils depends on soil texture, soil structure and the salinity of both soil and water. Untreated soil media itself is capable of retaining large quantities of water; the greatest increase in water retention by polymer treatment can be expected in media containing large pores.

Promotion of polymers as water conserving received a major boost by one large California water district noted for effectively educating the public and promoting water conservation. The district distributed packets containing a sample of polyacrylamide polymer granules. The packet’s label carried the following message:

How to save water without even trying. This package of ‘polyacryla-mides’ can help you save water, and make caring for your plants easier at the same time. The little beads inside attract and hold water up to 10 times longer than soil alone. Simply mix into the soil of a 6-inch potted plant, and water once. You shouldn’t have to water again for 2 to 3 weeks. Using polyacrylamides in all your pots and garden areas can reduce your watering needs by 60% or more! They are available in larger quantities at your nursery.

Greenhouse experiment

An experiment was conducted in the greenhouse on potted plants in three container sizes to check the validity of the claims. The containers were 5 inches in diameter by 5 inches high, 6 inches in diameter by 7 inches high, and 8 inches in diameter by 9 inches high. Approximate volumes of these containers were 1, 3 and 6 quarts. The potting mix consisted of 50% plaster sand, 25% bark shavings and 25% peat moss. Nitrogen, phosphorus, potassium and micronutrients were added to the mix. The potting mix was amended with 0, 1, 2 and 4 pounds of polymer per cubic yard of mix. Suppliers of the polymer recommend an application rate of 2 pounds per cubic yard of soil mix. (Although various polymers are marketed under different tradenames, they are similar in chemical nature and would have comparable effects.)

Marigold seeds were initially germinated in pure silica sand and nutrient solution. After about 2 weeks, the 4-inch-high plants were transplanted into the experiment’s containers. The numbers of plants per container were one, two and four in the 1-, 3- and 6-quart containers, respectively. Treatments were run in triplicate in a randomized block design.

The containers, irrigated regularly to maintain plant turgor, were periodically weighed to compute evapotranspiration and to determine water loss and, subsequently, how much water to apply without leakage from the container bottom. The plants were allowed to grow for 3 weeks, after which excess water was applied to each container; considerable drainage resulted.

After drainage had stopped, each container was weighed to determine the amount of retained water. The measurement allowed computing the difference in water retained in treated and untreated soil mix. No more watering was done and the plants were allowed to go to the wilting stage. The number of hours between the last watering and when the plants were judged permanently wilted was recorded. When the shoots were wilted, they were cut, dried at 150°F (65°C) and weighed. The water content of the soil mix was also determined at the wilting stage.

TABLE 1. Statistical significance (5% probability level) of polymer treatment effects in various container sizes*

TABLE 2. Polymer treatment effects on water retained after soaking in 8-inch containers

TABLE 3. Polymer treatment effects on number of days to wilt in 8-inch containers

Dime indicates approximate size of dry versus water-filled polymer crystals.


Results are summarized in table 1. Statistically significant polymer treatment effects were only observed in the 8-inch diameter container. In these containers, the polymer treatment significantly affected the amount of water retained in the soil mix after soaking and the number of days until the plants wilted. The polymer treatment did not affect the soil water content at the wilting time, indicating that water retained by the polymer was readily available to the plant. Plant growth and evapotranspiration were not significantly affected by polymer treatment in any containers.

The soil amended with the 4-lb/yd3 polymer treatment retained significantly more water than the control (table 2). The two lower polymer treatments did not retain significantly more water than the control. The number of days to wilting progressively increased with increasing polymer treatment (table 3) and the trend was statistically significant. Although the polymer treatment did increase the time to wilting, the increase was only about 1 day out of a week, and certainly would not allow a 6-inch potted plant to go 2 to 3 weeks without water, as claimed on the label of the water district’s sample package.


Concerning the utility of water-sorbing polymers in container-grown plants, polymers can sorb and hold water, but the quantity of extra water held in the container depends on the nature of the porous media and the size of the container. The mix used in our experiment was porous and typical of the medium used in containers. Water absorbed by the polymer was available for plant use and may extend the time between waterings. Note, however, that the extended time was not great, about 1 day out of 7.

Use of polymers does not conserve water. Water loss through evapotranspiration was the same for all treatments. Extending the time between irrigations does not conserve water because more water has to be applied at the time of irrigation to recharge the container to full water-holding capacity. In this experiment, the polymer treatments had no effect on plant growth.

Similar principles are involved in using polymers in the landscape. Potential benefits to be achieved depend on soil texture. Coarse-textured soils with large pores tend to retain less water than finer-textured soils. Thus, the amount of water that may be retained by incorporating a polymer would be greater in coarse-textured soils than in fine-textured soils.

Use of polymers should be coordinated with irrigation scheduling. If the polymer allows greater water retention in coarse-textured soils, irrigations can be applied less frequently but in greater quantity when applied. In a properly scheduled irrigation scheme, the total amount of water annually applied will be about the same with and without polymers. Only timing and amount are altered. This result is based on the fact that the polymer does not alter evapotranspiration. Water application must equal evapotranspiration, and the only factor that is altered is the storage capacity of the soil between irrigations. Thus, use of polymers is not a water conservation practice with proper irrigation management.

As is the case with almost all products, polymers can be effectively used to accomplish certain goals, such as increasing the water-holding capacity of some soils. They are not beneficial in all cases. Potential users must clearly identify what they hope to accomplish and evaluate whether the polymer will indeed accomplish that goal. Also, they must consider whether there are alternatives to accomplishing the same goal and then compare the relative costs.

Water$ave Range FAQ

What is the Water$ave Range?

  • Water$ave is a super absorbent polymer, also known as a water retaining crystals.
  • They absorb & retain up to 200 – 300 times its own weight in water & nutrients.
  • Slowly releasing these to the root system when needed by the plant.
  • Water$ave is a cross linked anionic co-polymer of acrylamide & sodium acrylate.

What is a Super Absorbent Polymer?

  • Super absorbent polymers are part of a group of acrylamide polymers. The group includes the polyacrylamide polymers.
  • These are very long chain molecules. With super absorbent polymers the long chains are cross linked to form a network or mesh structure.
  • This mesh has the ability to absorb water into the structure and to swell as the water is absorbed.
  • Water$ave is added to the soil in such a way that it is in contact with the root structure.
  • During watering or irrigation, water is absorbed by Water$ave granules attached to the plant’s roots.
  • The water is prevented from draining away & being lost.

Who should use Water$ave?

  • Anyone that have plants, trees, gardens, bushes, lawns, crops or any plant form that requires water to survive.

What happens to Water$ave when it dries out?

  • Eventually the water will be used by the plants and Water$ave returns to its dry form.
  • Water$ave remains active in the soil for many years & the cycle of water absorption & release can be repeated many times with only a very slight loss in efficiency over time.
  • Water$ave will break down when exposed to UV light.

What happens when Water$ave degrades in the soil?

  • The effects of the UV light & bacteria in the soil gradually breaks Water$ave down to water, carbon dioxide & nitrogen.

What are the general benefits of using the Water$ave Range?

  • Reduces your watering by up to 50%.
  • Reduces evaporation from your soil.
  • Will absorb water as well as nutrients and fertilizers and releases them to your plants as needed.
  • Improves soil porosity & aeration.
  • Will absorb any small rain falls and watering so water is not lost through run off.
  • Enhances plant growth & survival.
  • Protects the environment against drought and erosion.
  • Safe, non toxic & biodegradable.

How long will Water$ave last for?

  • Water$ave in the soil will work for 3-7 years, absorbing water, nutrients & fertilizers & releasing them as needed.

How much Water$ave do I use?

  • Generally, 2 teaspoons of Water$ave per plant will absorb 1litre of water, a little Water$ave will go a long way.
  • You can work out how much product is needed for each Water$ave Range product by using our online Polymer Calculators.

What package sizes can I purchase the Water$ave Range in?

  • We supply our Water$ave Range in various sizes from 140g jars to 20kg buckets!
  • We can supply Water$ave from small quantities used by home gardeners through to large quantities for farmers & large scale projects.

Is Water$ave safe?

  • If ingested, the acids within the stomach will start to break down the hydrated gels and the water is released into the stomach and the crystals are passed through.
  • Water$ave is safe to handle, non toxic & biodegradable.

Can I just put Water$ave on top of my garden or pot plants?

  • Yes, however Water$ave works best at the root zone of plants.
  • This allows the roots to tap into the hydrated Water$ave & draw water when needed.
  • Water$ave is UV sensitive it will start to break down & lose its effectiveness.

What makes Water$ave unique from other water retaining crystals that are available on the market?

  • Water$ave is unique among commercially available water retainers as it is available in a range of sizes to ideally match any soil type, location, crop and application.
  • This variety & commitment from Polymer Innovations ensures that you achieve the best possible results and the most from your Water$ave products.

Home > Moss Accessories > Water Retention Gel

Hortasorb – Water Retention & Bonding Gel

12 ounces of this amazing powder mixed with water, forms up to 30 gallons of slurry-like gel that has three perfect applications for transplanting and establishing moss.
1. Keeping moss moist following transplanting – The water management gel is proving itself highly-effective for helping to retain moisture beneath newly transplanted moss in areas where regular watering or misting will be difficult.
Just scratch the powder into the soil – one pound will cover up to 300 square feet. Once the moss has been pressed firmly into position, soak the area thoroughly to activate the gel beneath the moss. 1-2 spoonfuls per quart of room temperature water is all that is needed to activate the gel.
2. Creating a moss “slurry” – Transplanting entire sections of moss is still by far our most recommended and consistently successful transplanting technique for moss, but Hortasorb is ideal for creating a moss “slurry” in the blender, and simultaneously acting as a water retention medium, keeping the small moss fragments moist while they begin to grow.
This method is utilized for rocks and boulders, for very large areas of soil surface (thousands of square feet), or if cost is an issue and a potentially lower rate of success is acceptable. It also takes longer for the moss to become fully established.
3. Establishing moss on vertical surfaces – This gel also lends itself well to beautifying vertical surfaces. Moss enthusiasts can now cultivate lush, green textured moss on walls and rocks in the shade.
Not only does the powder (when mixed with water) form a gel that provides more consistent moisture to the moss fragments, but the introduction of a spoonful or two into the moss/water/buttermilk or beer mixture in the blender, creates a gel-like substance that when smeared onto a vertical surface, keeps it stuck in place even during heavy rains.

12 oz package $15.95 + $4.95 shipping Add to cart

Traditional “slurry” methods have provided minimal to moderate rates of success for moss enthusiasts looking to grow moss over large, shaded woodland areas, on vertical surfaces, or on rocks. This rate of success can now be greatly enhanced by adding a water-retention gel to the mix.
The benefits of this gel are two-fold. First, it helps provide more consistent moisture, which is crucial for establishing moss on any surface, particularly vertical surfaces. Second, the introduction of “gel” into the slurry makes it adhere much better to smooth or vertical surfaces.
In a blender simply mix the following components:
– 1 part moss
– 1.5 parts water (not too cold)
– 1-2 spoonfuls of gel powder
– ¼ cup of buttermilk or beer, or 2 spoonfuls of Liquid Sulfur or Aluminum Sulfate
Set the blender to “pulse” and/or continue to turn the power off and on to sufficiently “chop” up the moss into small fragments and blend the mixture (with the blender in the off position you may need to use your hand to re-orient the mixture in the blender and then start it again to mix it properly. Within 2-5 minutes the gel will set, and a thick, applesauce-like gel will be formed. If the mixture is too runny, just add more powder and mix again.
The best mosses to use for this application are Hypnum / Fern Moss (sold at lower costs in “bulk” on this website), Rock Cap Moss (also available through Moss Acres), and any mosses found growing locally in the area. Obviously, moss does not to be watered as frequently with the use of Hortasorb water retention gel.

Water Retaining Gel Crystals For Plants

Water Retaining Gel

Water Retaining gel is also called potassium polyacrylate or SAP.It is a new function polymer with unbelievable water absorption ability. Actually, 1 gram water retaining gel can absorb 300-1000 gram water.After absorption , it turn to water gel like this :

For Plants

Now let’s talk about advantages for plants. It can absorb water and turn to water gel when it is raining or irrigated. And when the dry season coming, water gel can release water back to plant’s root.

So you can regard it as a “Mini-reservoir“.


Here is the mainly advantages for plants:

–Improve seed germination and emergence to give plants an early, health start.

–Save the irrigation, increase crops and fruit yield.

–It contains Potassium, Phosphorus Nitrogen and release the fertilizer efficiency slowly.


Common plants and crops

15 to 30 kg per acre dosage, along with seeds hole application or ditch application to the soil around the seed. The seed germination rate can effectively improve and promote seedling growth. Gets success planting corn in the U.S, pature in arid area of Inner Mongolia, potatoes grown in Cape Verde Africa, and potato yield increase more than 2 times.

Seed coating

For Seed coating use, the particle size of SAP should be 0.3 mm or less.It can help seeds emergence quickly, strong and good disease resistance.This is the easy available way to use SAP for plants in drought area, which also with small quantity, low cost and good performance.

Gardening, horticulture and landscape

SAP is ideal for mixing soil matrix, for indoor and outdoor pots, planters, window boxes, balconies, terraces, roofs, hanging, gardens and city landscape. Planting shrub, flower, grass, vegetables are also available. Using SAP can bring water-saving, labor saving, time-saving benefits and reduce the drought or wilting risk causing by long time no watering the plants, longer the green time and the blossom period.

Lawn and golf course

Application in golf and lawn can save about 50%-70% water, reduce the cost of maintenance, and ave about 30%-50% fertilizer. Lawn grows faster, healthier, and the green last longer.It also make less pollution caused by the loss of fertilizer.


Using 10-20g SAP can double the survival rate of young trees when planting tree seedlings (bare root).

For adult deciduous fruit trees, put the SAP with organic fertilizer, taken with a ring groove or furrow in the root area. The dosage is up on the soil condition, tree size and the ditching situation, should generally be 0.3% of the backfill soil and fertilizer.

Gardening with Hydrogel Crystals


Here are some of our favorite tips for using Water Jelly Crystals in your garden and for all your landscaping needs:


HydroSource (cross-linked polyacrylamide) is a long lasting, easy to use, water absorbing soil additive. In gardens, house plants, and landscaping it increases the soil’s water holding capacity. You can either improve the growth of the plant or decrease the watering frequency. It usually lasts 4-5 years in the soil.

General Performance

One pound of HydroSource will absorb up to 35 gallons of rainwater or snowmelt and 20-25 gallons of tap water, depending on the salt content of the water. HydroSource can be applied wet or dry. Dry granules are usually easier to use, but soak them thoroughly to fully fill them with water. When hydrated, the granules look like chunks of clear gelatin about 1/2 inch in diameter.

Dry Application

For large quantities of potting soil or backfill around trees and shrubs use 1.5-2 pounds/ cubic yard of potting soil or backfill or 1 ounce/ cubic foot of soil. For small quantities of potting soil use 1/2 tsp per quart of soil. Note: Since dry granules swell to many times their original size when water is added, 15-20% swelling room must be left in each planting hole or flower pot to compensate.

Wet Application

Best for small applications such as repotting house plants and planting shrubs, small trees, and bedding plants. 1/2 tsp of dry granules absorbs approximately 1 cup of water. 1 ounce of dry granules absorbs approximately 1 1/2 cups of water. 1 pound of dry granules absorbs approximately 30 gallons of water. Mix the granules in water and allow them to stand for 60-90 minutes (hot water works faster). Once you have the polymer all soaked up, the application rate is roughly one part hydrated polymer to four parts soil.

House/Office Plants

  • 6″ pot (2/3 gal) – use 1 tsp dry or 2 cups hydrated
  • 8″ pot (1 1/2 gal) – use 2 Tbsp dry or 6 cups hydrated
  • 5 gallon pot – use 7 tsp dry or 1 gallon hydrated

Note: Mix HydroSource® in lower half of the pot because the water tends to flow quickly through porous potting soil before the granules near the top have time to re-hydrate fully.


Using the above rates, mix granules or hydrated gel thoroughly in the lower half of the pot. If using dry granules, fill the soil only to within 1 inch of the pot rim to prevent swelling out of the pot.

Existing Plants

Depending on container size, use a pencil or wooden spoon handle to poke 4-6 holes around the plant, going to the bottom. Divide the correct amount of dry granules evenly among the holes, pushing them to the bottom. Water slowly to hydrate the granules. Wait at least 2-3 weeks before changing watering intervals to give feeder roots a chance to grow into the granules.

Vegetable and Flower Gardens

Use 4-5 pounds/ 100 sq feet for low-water adapted flowers and up to 10 pounds/100 sq feet for water loving vegetable and flowers. Hint: The addition of weed-barrier fabric will further reduce the need for water or weeding. By hand, or using a spreader, distribute the granules evenly over the leveled bed and then turn under. Bedding plants may be given a quick start by mixing a handful of hydrated gel in the back fill of each plant, taking care not to leave clumps of gel. Water the bed thoroughly after planting.

Trees and Shrubs

Dig a hole 5 times the diameter, but no deeper than, the root ball or container. To figure out the amount of dry granules needed to mix in the backfill, just calculate the amount of backfill and figure one ounce of granules per cubic foot. The bigger the hole the more polymers you can use and the morewater storage you’ll gain.

New or Seeded Turf

Watering intervals can be extended approximately one day for each 7 1/2 pounds of HydroSource® per 1000 sq feet given evaporation rates of .25″ per day. For example, 15 lbs of granules normally stores 1/2″ of extra water (two additional days between waterings) and 30 pounds stores 1″ of water (four additional days between watering). Warning: To avoid making a soft lawn, never use more than 5 pounds of HydroSource® per tilled inch per 1000 square feet. Thus, 20 pounds must be tilled in 4 inches; 30 pounds 6 inches. Increase application rate roughly 10% over sloped areas. Save one pound to spread over the top of each 1000 sq ft. before laying sod (but not if you are seeding, as it just breaks down in the wet phase if not covered by soil.) Water thoroughly and slowly. By hand, or using a spreader, distribute the granules evenly before rototilling to appropriate depth.

Additional Info

For more information on the science behind Water Jelly Crystals visit our Water Jelly Crystal experiment and our Water Absorbing Crystals experiment.

Look for Steve Spangler using superabsorbent “Hydrogel” polymers as the 2008 National 4-H Youth Science Day Spokesperson.

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