FAQ

Here you will find answers to frequently asked questions about our innovative products and our commitment to sustainable solutions. Whether you want to learn more about the application or find out about the ecological benefits – you’ve come to the right place. Our aim is to provide you with detailed information and practical advice so that you can get the best out of our products. If you have any further questions, please contact us directly.

DROUGHT STRESS, WATER, AND PLANTS

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What role does the soil play?

Soil with good structure and sufficient organic matter can absorb more water and retain it for longer. On light, sandy, or compacted soils, the water-holding capacity is significantly lower.

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What exactly is drought stress?

Drought stress (or water stress) is the result of a lack of water in plants. It occurs when transpiration is greater than water uptake, resulting in a drop in internal pressure in the leaf cell. Abiscic acid forms in the roots and leaves and causes the stomata to close. This leads to a decrease in the internal CO2 concentration and subsequently to an inhibition of photosynthesis.

The plant evaporates more water than it can absorb - it comes under stress, grows more slowly and becomes more susceptible.

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How can I tell if my crop is suffering from drought stress?

Typical symptoms include limp or curled leaves, dull leaf color, browning leaf margins, and significantly stunted growth. In trees and perennial crops, these symptoms are accompanied by premature leaf drop, thinning canopies, and dead shoots. If such symptoms are overlooked for an extended period, the plants may eventually die.

(See  https://www.forum-verlag.com/fachwissen/kommunales/trockenstress/)

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What exactly is drought stress?

The plant evaporates more water than it can absorb - it comes under stress, grows more slowly and becomes more susceptible.

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Why do plants wilt?

Plants wilt mainly due to a lack of water, which plays a crucial role in their life processes. Water is essential for various metabolic processes in a plant, including photosynthesis and nutrient transport. Step-by-step explanation of why plants wilt:

Water shortage: If a plant cannot absorb enough water from its surroundings, whether due to drought, poor irrigation or other environmental factors, a water shortage occurs.
Compensation by cells: Initially, the plant's cells try to compensate for this deficiency by using water from their own internal reserves.
Decrease in internal cell pressure (turgor): The turgor pressure is the pressure of the cell contents against the cell wall. Water helps to maintain this pressure. If there is a lack of water, the turgor pressure cannot be maintained as the cells begin to lose volume.
Reduced stability and wilting: Turgor is crucial to the plant's ability to maintain its structure and stand upright against gravity. As the turgor decreases, the plants lose their stiffness and begin to wilt as they are no longer able to support themselves effectively.

Wilting is therefore a visible sign that a plant is under water stress and does not have enough water available to maintain its vital functions.

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Can a plant be watered too much?

Yes, too much water in the soil displaces the soil air and deprives the roots of their vital oxygen and, in the worst case, suffocates them. The plant's pumping system collapses and the above-ground parts of the plant are no longer supplied with sufficient nutrients or water.

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What is the role of roots?

Alongside the stem and the leaf, the root is the most important organ of a plant. It mainly serves to absorb water and the minerals dissolved in it. Roots also ensure that the plants are attached to their location and store reserve substances. The area of the soil influenced by the roots is called the rhizosphere. The rhizosphere is the habitat of various organisms such as nematodes or fungi, which are in constant interaction with the plants and thus reflect the nature of an entire ecosystem.

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Why doesn't watering more always help with drought stress?

If the soil is compacted or waterlogged, water cannot seep in easily and instead pools on the surface or runs off, rather than reaching the root zone. Such soils lack pores that store water and simultaneously provide air to the roots; too much water can then lead to oxygen deficiency and root damage. Therefore, a loose, crumbly structure with good humus content is crucial—not just the amount of water applied.

Products and Applications

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What products does Green Legacy offer?

Polygrain - water storage granules with starter fertilizer, ideal for young plants.
Composition: 58 % cellulose, 40 % superabsorbent, 2 % starter fertilizer (NPK + Mg)

Polygrain Tab 5 – Polygrain in a convenient 5-gram tablet for manual planting and difficult terrain; no measuring required, clean, and easy to transport.

PolYSORB - pure superabsorbent (without cellulose & fertilizer) with maximum water retention; ideal for post-inoculation and for large-scale applications when no starter fertilizer is required.

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What is the difference between the products?

Polygrain: up to 200-fold water retention, with starter fertilizer for a quick start; the cellulose is quickly broken down by microorganisms and promotes soil activity.

Polygrain Tab 5: Same effect as Polygrain, but in tablet form—ideal for individual plantings and manual application.

Polysorb: > 300-fold water retention, without fertilizer & cellulose - ideal for re-inoculation or when only maximum water retention is required.

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How much water can the products store?

Polygrain & Polygrain Tab 5: up to 200× its own weight.

PolYSORB: over 300× its own weight.

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How long do the products work in the soil?

All products (Polygrain, Polygrain Tab 5, Polysorb) remain effective for approximately 3–5 years. During this time, they can repeatedly absorb and release water and are subsequently completely degraded by microorganisms.

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For which crops are the products suitable?

Polygrain: for perennial crops such as vines, fruit, forest plants and in horticulture and landscaping - especially for young plants where a starter fertilizer is also required.

Polygrain Tab 5: particularly useful for individual plantings in viticulture, fruit growing, and forestry, or in difficult terrain where work is done by hand.

Polysorb: suitable for larger crops and for subsequent inoculation when no starter fertilizer is required and maximum water retention is the priority (e.g. arable farming, viticulture, horticulture).

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In which areas can the products be used?

Polygrain, Polygrain Tab 5, and Polysorb are used in many areas of agriculture and forestry, as well as in gardening and landscaping. They can be used for both new plantings and existing plant populations (through re-application).

Typical fields of application are

Forestry: reforestation, young plants, re-inoculation in stands
Viticulture and fruit growing: new plantings, individual plantings, replanting
Gardening and landscaping (GaLaBau): Parks, green spaces, roadside greenery, gardening
Ornamental plant and vegetable cultivation: young plant cultivation, planting in commercial horticulture
Lawn and sports turf areas: Turf, reseeding, new establishment
House and allotment gardens: perennials, shrubs, hedges, trees
Arable farming: Crops on sites with low water retention capacity

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How do the products work for crops with or without irrigation?"

For irrigation-intensive crops such as in horticulture, the amount of irrigation can be significantly reduced. This reduces costs, saves working time and conserves water resources.

For crops or areas without irrigation - e.g. in forestry - failure rates of young plants are reduced and growth is accelerated. Maintenance work (e.g. mowing) and costs for manual replanting can thus be reduced.

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Do the products also improve the soil?

Yes. In addition to improving water supply, all of these products also improve soil quality. Therepeated swelling and shrinking of the material loosens the soil, increases its porosity, and improves aeration in the root zone. At the same time , this creates an optimal environment for microorganisms that promote the decomposition of organic matter, mobilize nutrients, and increase soil activity.

In Polygrain and Polygrain Tab 5, the cellulose—which is rapidly broken down by microorganisms—further enhances this effect.

The result: a more active, healthier soil that offers plants better growing conditions in the long term.

SPORTS TURF, GOLF COURSES, AND GREEN SPACES

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How much water does a soccer field use?

Technical papers from the German Turfgrass Society and guidelines based on DIN 18035-2 show that sports turf typically requires about 2 to 5 liters of water per square meter per day during the growing season in summer. For a standard-sized soccer field measuring approximately 7,600 square meters, this amounts to—depending on weather conditions—several tens of thousands of liters of water per day, while annual irrigation requirements are cited in technical sources as ranging from about 0 to 250 liters per square meter per year.

[Source:  German Turfgrass Society,  DIN]

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Why is water consumption at sports fields a problem?

Sports turf must be irrigated, especially during the warm, dry months when evaporation rates are high and water resources are scarce. At the same time, longer dry spells caused by climate change mean that without efficient irrigation, both turf health and regional water resources are put under strain. Efficient water management therefore not only reduces costs but also contributes to climate adaptation and resource conservation in sports.

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What does DIN 18035-2 specify regarding the irrigation of sports fields?

DIN 18035-2 “Sports Fields—Part 2: Irrigation” specifies requirements for the design, installation, and operation of irrigation systems for grass, clay, and synthetic turf surfaces, as well as golf courses. Among other things, the standard includes guidelines for irrigation rates based on temperature, evaporation, and location, which are referenced in technical articles and tables on the irrigation of DIN-compliant sports fields.

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How can Polysorb reduce water consumption on sports fields?

Polysorb is a water-retaining granule made from superabsorbent polymers that is applied to the root zone of the lawn and can store more than 300 times its own weight in water. The stored water is gradually released back to the roots, which extends watering intervals, reduces peak watering, and allows for better utilization of rainfall.

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Is Polysorb compatible with existing irrigation systems?

Polysorb is mixed into the soil and does not alter the operation of the irrigation system; rather, it increases the water-holding capacity of the turf subbase. In technical articles on sports field maintenance, the soil—or the turf subbase—is explicitly described as a water reservoir designed to ensure a steady supply of water to the roots; water-retaining granules support precisely this function.

HYDROGELS & SUPERABSORBENTS: A SIMPLE EXPLANATION

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What is a superabsorber?

Superabsorbents, or superabsorbent polymers (SAP), are materials that can absorb and store large quantities of water in relation to their own weight. This characteristic makes them particularly valuable for agriculture, especially in dry regions or during periods of drought, as they help to use water efficiently and retain moisture in the soil for longer.

At Green Legacy, we produce biodegradable superabsorbent polymers (SAP). Our eco-friendly superabsorbents contain no microplastics and thus help minimize water loss, reduce erosion, and improve soil structure. They support sustainable agriculture and reforestation without compromising soil or water quality.

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What is a water-retaining granule, hydrogel, or superabsorbent?

Water-retaining granules are the dry, granular form in which our products are supplied (e.g., Polygrain, Polysorb, or Polygrain Tab 5 in tablet form). When these granules come into contact with water, the particles swell significantly and form a hydrogel —that is, a water-filled, sponge-like gel directly in the root zone.

The way it works is based on so-called superabsorbers: these are polymers that can absorb enormous amounts of water - many times their own weight. When swollen, they retain the moisture in the soil and release it to the plant roots as required. At the same time, nutrients are also bound and are available to the plant for longer periods of time.

In short: granulate is the form you apply - hydrogel is created from it in the soil and acts like a water reservoir directly at the root.

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Do water-retaining granules also improve nutrient utilization?

Yes. Studies on hydrogels show that water-retaining granules not only store water but can also improve plants’ nutrient uptake and nutrient efficiency. In particular, hydrogels can significantly increase the uptake of nitrogen (N), phosphorus (P), and potassium (K) —that is, the most important macronutrients.

The reason for this is that water and dissolved nutrients remain available directly in the root zone for a longer period of time. Hydrogels act like small storage reservoirs in the soil: they absorb water and the nutrients dissolved in it and gradually release them back to the plant as needed. This ensures a more consistent supply and reduces stress caused by dry spells.

(Source: Agbna & Zaidi, 2025: Hydrogel Performance in Boosting Plant Resilience to Water Stress—A Review,  https://www.mdpi.com/2310-2861/11/4/276)

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Does the use of hydrogels specifically promote root formation in crops?

Yes, scientific research clearly demonstrates this positive effect on root structure. Recent studies show that, for important crops such as corn, wheat, and tomatoes, the use of hydrogels leads to higher root density and deeper soil penetration. Thanks to this more extensive root system, plants can access water and nutrients more effectively, which significantly increases their resilience to dry periods.

(Source: Agbna & Zaidi, 2025: Hydrogel Performance in Boosting Plant Resilience to Water Stress—A Review,  https://www.mdpi.com/2310-2861/11/4/276)

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Do hydrogels, when used in combination with fertilizer, improve root development?

Yes. Independent scientific studies show that hydrogels significantly promote root development, especially when they serve as a medium for nutrients. Scientifically, this effect can be explained by three main factors:

Improved root structure: Plants grown in soil amended with hydrogel develop a more extensive root system with higher biomass, longer roots, and greater root density.
Targeted nutrient release: The incorporation of fertilizers (such as NPK) into the hydrogel allows for controlled release directly in the root zone. This has been shown to promote early root development and seedling vigor.
Long-term effect: Because hydrogels store water and nutrients over a long period of time and release them gradually, roots can penetrate deeper into the soil to tap into these reservoirs, which significantly increases tolerance to drought stress.

(Source: Agbna & Zaidi, 2025: Hydrogel Performance in Boosting Plant Resilience to Water Stress—A Review,  https://www.mdpi.com/2310-2861/11/4/276)

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What benefits do superabsorbents (hydrogels) offer for soil structure?

Studies show that superabsorbents (hydrogels) act as soil conditioners, by reducing soil compaction and increasing the soil’s porosity (aeration). The repeated swelling and shrinking of the hydrogel granules creates new pore spaces and more stable soil aggregates. This improved soil structure reduces the soil’s mechanical resistance, making it physically easier for roots to penetrate deeper into the soil and develop a stronger root system. In addition, increase water storage capacity and reduce nitrogen leaching from the soil.

(Source: Agbna & Zaidi, 2025: "Hydrogel Performance in Boosting Plant Resilience to Water Stress—A Review," https://www.mdpi.com/2310-2861/11/4/276)

Safety, environment & certifications

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Are the products harmful to the environment?

No. All products are safe and environmentally friendly. They do not pollute soil or water.

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Are the products biodegradable?

Yes. Polygrain, Polygrain Tab 5, and Polysorb are effective for 3–5 years and are then completely broken down by microorganisms in the soil, leaving no harmful residues.

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What certifications do the products have?

Polygrain: PEFC-certified

The PEFC seal (Program for the Endorsement of Forest Certification) stands for sustainable forestry and the traceability of wood and cellulose products worldwide. PEFC certification ensures that the cellulose used for Polygrain comes from sustainably managed forests and can be fully controlled - from its origin to the finished product.

Polysorb & Polygrain: CE-marked

The CE marking is a mandatory quality and safety mark within the EU. It confirms that Polysorb, Polygrain, and Polygrain Tab 5 comply with all relevant European standards and directives applicable to their product category. For users, this means: verified product safety, consistent quality, and compliance with the legal requirements of the EU single market.

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Are the products approved for use in food production?

Yes, Green Legacy products are approved in Austria as soil amendments. This approval covers all crops and therefore also allows their use in food production.

APPLICATION / APPLICATION

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How are the products used?

Proper application is crucial for the effectiveness of the granules and should be carried out carefully. Proper application is crucial for the full effectiveness of Polygrain, Polygrain Tab 5, and Polysorb. All products work exclusively in the soil, directly in the root zone—applying them to the soil surface is ineffective. Therefore, they should be applied specifically to the root zone with every application.

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Use for new plantings

For new plantings, the granules are placed in the planting hole or planting furrow, below the roots or the seedling. This creates a water reservoir directly where the plant needs it most. The products can be used both in dry form (granules) and in already swollen form (gel). The gel form has the advantage that the plant is immediately supplied with water. If the product is applied in dry form, it should be watered or slurried in soon afterwards so that it can swell.

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Re-inoculation of existing cultures

In addition to new planting, the products can also be used for subsequent inoculation. The granules are inserted into slits or holes in the soil close to the root area to subsequently improve the water supply of existing crops. Especially in sensitive locations, long dry periods or larger crops, this can reduce failure and stabilize the water supply.

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Mechanical and manual application

Principle: All products are always applied below the surface in the root area - never on the surface. Depending on the product, it can be applied manually or mechanically.

Polygrain & Polysorb

These two products can be applied manually (e.g. in the planting hole, in slots/boreholes along the row) or mechanically. Typical mechanical methods are, for example, planting machines (forestry/vine/fruit), row injectors, slitters or dosing hoppers on planting machines. Inoculation with a lance - i.e. the precise application of granules directly into the root zone of existing plants - is also possible and has proven particularly effective in viticulture and forestry.

The dry granulate form is generally used for machine application; pre-swollen gel is generally not suitable for machines. After dry application, watering or slurrying should always be carried out promptly so that the granules can swell and develop their full storage function.

Polygrain Tab 5

The tablet form is intended exclusively for manual application. One tablet (5 g) is placed directly in the root zone - ideal for single plantings, replanting and in difficult terrain (steep slopes, rough areas) where working with machines is not practical. Advantage: no measuring, clean handling, easy transportation.

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How do I dose the products?

The exact application quantity always depends on the planting hole size, soil conditions and plant size or tree size. To ensure that the products work optimally, we coordinate the quantity and procedure with you individually in a personal consultation.
General dosing recommendations can be found in the tables on the application pages of www.greenlegacy.at

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Can I overdose the products?

Overdosing does not directly harm the plants, but can cause problems in practice. The surface of rolled turf can rise if too much material swells underneath. Overdosing can also cause plants in containers or pots to be pushed upwards. Furthermore, overdosing does not make economic sense. Therefore, always adhere to the dosing recommendations and advice.

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How often do I have to use / apply the products?

Polygrain, Polygrain Tab 5, and Polysorb typically remain effective in the soil for 3 to 5 years. During this time, they can repeatedly absorb and release water and are subsequently completely broken down by microorganisms.

To ensure continuous effectiveness, we recommend repeating the application after five years at the latest. This subsequent inoculation supports the optimum soil structure, water storage capacity and nutrient supply and thus contributes to healthy and stable plant growth.

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Can the products also be used retrospectively?

Yes. Polygrain and Polysorb are very well suited for replanting existing crops. The material is applied directly to the root zone—either in spots or in rows—using a lance, through slits, or through drill holes. This improves water supply even after the fact and reduces crop losses.

Availability, downloads & advice

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Where are the products available?

Our products are available through numerous partners (e.g., Lagerhaus, Maschinenring, Profiforst, arborealis, and many more).
You can find the current list of all distribution partners here: Distribution Partners

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Where can I find data and security sheets?

All technical data sheets and safety data sheets are available for download on our website. You will find the links in the footer of the website.

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Who can advise me on the best way to use it?

Our team of specialist advisors will be happy to support you personally. You can find all contact details on our team page.