Soil additives

Ensuring the survival of plants in the long term in drought and adverse soil conditions is the main task of soil aggregates, regardless of whether they are trees, shrubs, grasses, shrubs or ornamental plants.

GEFA is constantly developing new product solutions and continuously revising the existing product range.

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We're here to support you.

Specialist Dipl.-Ing. (FH) Marius Wiede

Your contact for soil additives; after working as a greenkeeper in the golf course sector and as an engineer in a planning office, he now supports the GEFA Team with his multiple years of vocational experience.

+49 (0) 2151 / 49 47 70
Email Marius Wiede

Improve the soil with STOCKOSORB®

- increases the water holding capacity of soils and substrates
- reduces the frequency of watering
- ensures the growth of plants
- enables plant growth in dry locations
- has a long-term effect
- is environmentally friendly
- activates plant growth sustainably

Application notes

Tree and plant locations are often not ideally suited - the substrate has to be modified, woody plants have to be rehabilitated at the same time, clients are increasingly demanding growth guarantees.

Cost savings in communal greenery - more and more cities and municipalities are choosing STOCKOSORB® or GEFA Arbovit® for summer and tub planting, as the maintenance effort is significantly reduced.

More than less water

More than less water

Ensuring the survival of plants in the long term in drought and adverse soil conditions is the main task of soil aggregates - regardless of whether they are trees, shrubs, grasses, shrubs or ornamental plants.

GEFA is constantly developing new product solutions and continuously revising the existing product range. The well-known STOCKOSORB® water storage tank has been modified again and significantly improved.

The new STOCKOSORB® has particular advantages in terms of its water absorption capacity. Under practical conditions, a 50% increase in the water retention capacity under soil conditions could be achieved. In addition, the innovative water storage granulate has a higher cycle stability and thus a longer service life. Planners and executors can thus save water even more effectively and cost-effectively and bridge periods of drought.

There are also further advantages in use, for example when mixing into substrates. The new STOCKOSORB® is less sensitive to moisture, i.e. the risk of clumping is greatly minimized.


Scientifically proven benefits

Scientifically proven benefits

Studies by the University of Göttingen, Institute for Forest Botany, confirm the many advantages of STOCKOSORB®.

The research structure:

- Soil: sandy soil in a 30 l container
- Plants: Aleppo pine (Pinus halepensis)
- Variants: sandy soil without STOCKOSORB® 3g / l - sandy soil with STOCKOSORB® 4g / l
- 4 and 8 weeks of even watering, then no further watering
- Climate: greenhouse 30 - 40% humidity / 30 ° C - climatic chamber 30% humidity / 27 ° C

research results

Evaporation reduced
1. Evaporation

In terms of water capacity and availability, the sandy soil resembles a clay soil after treatment with STOCKOSORB®. Evaporation from the soil is reduced by around 20% and the plant effectively has more water available and it suffers less from drought stress. The water stored in the ground can thus be used to the maximum for productive transpiration.

Plant biomass increases
2. Plant biomass

With STOCKOSORB® the soil stays moist longer and the plant biomass increases. The addition of STOCKOSORB® (4g / l sandy soil) leads to a three times higher growth in the shoot and a tripling of the root mass. (Sprout growth in cm, root mass g / DM.)

Soil compaction
3. Soil compaction

STOCKOSORB® acts like a soil colloid. When water is absorbed, the hydrogels swell and thus increase their volume. This reduces the density of the soil by 23.4%. When the soil begins to dry out, the hydrogels shrink again and form stable cavities. This loose structure of the soil, created by swelling and shrinking, is permanently retained. Due to the decreasing storage density, the soil treated with STOCKOSORB® is loosened and thus the rooting is facilitated.

Waterlogging is avoided
4. Waterlogging

The pore volume of the soil treated with STOCKOSORB® (3 g / l soil) increases by 40.5% compared to the untreated soil. The soil becomes looser and allows water to pass through better. If STOCKOSORB® has reached its maximum absorption capacity, no more water is stored and the excess water flows away. The combination of all these properties successfully prevents waterlogging in the root area. This low sensitivity to moisture is also an advantage when mixing into substrates, because it greatly reduces the risk of clumping.

5. Germination

In 2010 the University of Hohenheim, Stuttgart, examined the survival rate of lawn plants when used with and without STOCKOSORB®. The water storage granulate is scattered before sowing and then worked evenly into the vegetation layer from a depth of approx. 15 cm. This significantly increases the water storage capacity of the substrate. In the germination phase, there is a larger safety buffer for germination and the survival rate of the lawn plants increases significantly.

Global warming and climate change

Global warming and climate change

Man-made global warming is advancing. The months of February, March, May and June 2015 were the warmest on record.

Heat records will continue to rise. The probability of extreme weather events due to very hot periods increases, as the entire temperature profile is now at a higher level.

The green industry must therefore think ahead. The soil should be able to store the last rainfall for as long as possible. With STOCKOSORB® the existing soil can be improved so that it can store the vital water in significantly higher quantities.

STOCKOSORB® Important questions and answers

STOCKOSORB® Questions and answers

In connection with the effect and use of STOCKOSORB® and related soil additives, several questions arise time and again, which we answer briefly and concisely:


STOCKOSORB® - water storage with potassium fertilizer effect (> 24% K²O total). It stores up to 300 times its own volume in water and makes it available to the plants; in use in landscaping and agriculture for over 20 years. Chemically: cross-linked homopolymer based on potassium.

What distinguishes STOCKOSORB® from other absorbers?

Usually the chemical composition. Often hydrogels are only made to store water but not to release it (e.g. in diapers). In addition, there are absorbers that are based on sodium, which salty the soil, only have a very limited effect.

Where does STOCKOSORB® make sense?

In principle for all plantings where it is about the water retention capacity of soils and Increasing substrates, bridging dry periods and improving growth successes.

Does the use of STOCKOSORB® save costs?

Yes, scientific studies and the Our customers' experiences have shown:

• Up to 60% reduction in the number of runners
• prevents plant failures
• reduces the use of fertilizer

How long does STOCKOSORB® work?

With full performance about 5 years. After that, the granules in the soil are demonstrably biodegraded.


Alginure granulate

Vigorous plant growth and a colorful world of flowers require vital soil life. Even slight disturbances of the sensitive soil structure impair the plant growth and increase the maintenance effort. Common causes are waterlogging, insufficient soil contact, drought or soil compaction.

With the primal power of seaweed

Our alginure products are based on the brown alga Ascophyllum nodosum. The brown algae native to the North Atlantic is characterized by its rich ingredients such as alginates, trace elements and secondary plant components (auxins). The alga is harvested sustainably and completely processed in the Tilco digestion. Thanks to the gentle process, the plant components are particularly protected and are released in a manner that is readily available to the plants. The result are alginure products that work biologically, physically and biochemically. The soil life is activated and the plant is vitalized. Alginates promote the formation of clay-humus complexes whereby the crumb structure is improved. The secondary plant components stimulate root and plant growth. The intensive sorption properties improve the utilization of irrigation and precipitation water.

Optimizes the soil structure and activates soil life

An effective bioactivator based on humic acid, with its 5% share, ensures fast and, at the same time, long-term healthy plant growth. The product component can be easily absorbed by the root, the carbon content promotes beneficial ones Soil organisms. In addition, the humic acids are able to bind salts and pollutants.

Mineral plus for soil and plants

The polyuronic acid / alginates contained in the Alginure Soil Granulate 1 combine with the soil particles to form clay-humus complexes. This increases the nutrient availability and storage power as well as the water and air capacity of the soil. The resulting crumbly structure optimizes the development of the root ball and plant growth.


Increased storage capacity by adding Alginure soil granulate 1

The figure shows the influence of Alginure Soil Granulate 1 on the water storage capacity of a normal topsoil. Without Alginure Soil Granulate 1, water flows off directly (left) without being available to the plant in the root area. Alginure soil granulate 1 increases the storage capacity through a pronounced gel formation. This means that water and nutrients are available for the plant.

Alginure soil granulate 1 is an organic mineral potassium fertilizer based on brown algae with magnesium and sulfur.

- Improves soil fertility
- Activates soil life
- Promotes root development
- Suitable for organic farming

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Novihum permanent humus

Novihum permanent humus

With NOVIHUM® as a substrate additive, you give your trees the decisive edge for optimal, permanent growth results. NOVIHUM® supports healthy root development, makes your trees resistant to environmental factors, improves water use efficiency and provides an effective nitrogen source.

NOVIHUM® is a unique soil and substrate improver, which in its structure is equivalent to a natural permanent humus and causes an increase in soil and substrate fertility. According to a patented process that was developed at the TU Dresden, the natural raw material lignite, which has a high concentration of humic substances, is enriched with nitrogen.

The nitrogen that is now bound in the structure of the humic substances becomes dependent from its binding form, released over a longer period of time and made available to plants. The particularly favorable C / N ratio of 11 ensures that the stable organic substance works, which benefits soil fertility and substrate quality. NOVIHUM® consists of over 80% humic substances (humic acids, fulvic acids and humins), which improve plant development and vitality in the soil and root space. Freedom from fungi, weed seeds, pathogens, pollutants and constant quality are features that distinguish NOVIHUM®.

The effects of the permanent humus granulate NOVIHUM® are particularly interesting with regard to the problems of urban trees and plantings in urban areas with their difficult location conditions and can make a decisive contribution to healthy development. So permanent humus-like humic substances are able to increase the drought stress resistance and water use efficiency of plants and thus maintain vitality even under adverse conditions.

The phytohormone-like mode of action of humic substances promotes the development of the root system of plants, which has an overall positive effect on tree health and its development. The functional groups of humic substances prevent nutrients from being leached out, as nutrients accumulate on them and are released to the roots when required be.


Mode of action NOVIHUM®

NOVIHUM® corresponds in its properties to high-quality, natural permanent humus. As a slowly flowing nitrogen source, NOVIHUM® increases the permanent humus content and optimizes the starting conditions for optimal plant growth. At the same time, NOVIHUM® initiates a higher humus accumulation rate, especially on weak, sandy locations. As a result of the permanently increased productivity of the plants, the permanent humus content in the soil increased by NOVIHUM® remains in the long term received.

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What is NOVIHUM®?

NOVIHUM® is a technology for the production and effective use of standardized permanent humus products. We understand a standardized permanent humus product to be a soil improver that is characterized by the following properties:

- Consistent quality, all year round, anywhere
- Perfect processability, free of harmful substances
- Guaranteed active ingredient content and high transportability
- 20 years of experience, hundreds of attempts in commercial horticulture, agriculture, landscaping, at recognized research institutions. Worldwide!



Humic substances are almost all-rounders among the soil additives and take on much more than just the task of a pure nutrient store. PERLHUMUS® and POWHUMUS are among the most effective and high-quality products in this area. PERLHUMUS® is the specialist with long-term effects. With POWHUMUS, successes can be achieved in a short time. Combinations with mycorrhiza and STOCKOSORB® have proven particularly useful in tree renovation.


Humic substances can be found in all soils and bodies of water. They arise from plant breakdown products and can be broken down into humic, humic acid, fulvic acid and ulminic acid by extraction. Their salts are called humates, fulvates and ulmates. As the main fraction, humic acid forms the biological center of humus.

Basically, the use of humic substances has an extremely positive effect on our soils. Problems such as salinization, calcification, decrease in soil fertility, the destruction of useful microorganisms, increased erosion, the increased occurrence of plant diseases and the accumulation of toxic residues in the soil can be minimized by PERLHUMUS® and POWHUMUS.

The high-performance PERLHUMUS® and the water-soluble concentrate POWHUMUS are made from leonardite, a soft brown coal with up to 85% humic acid. The contained humic acids are hardly broken down further in the soil. This ensures a permanent humus supply. This can also be used to guide roots in certain directions and even in depth.

Effects on different floors

compacted clayey soil:
Is loosened up & structurally improved
light sandy soil:
the cation exchange capacity is increased, nutrients are less washed out
acidic soil:
is neutralized and more alkaline Soil:
High pH value is buffered, nutrients are digested in a way that is available to plants.
Salinated soil:
Salts are broken down and thus harmless
Soil enriched with biocides:
Harmful residues are immobilized

Purchase POWHUMUS®

PERLHUMUS® Naturally active

PERLHUMUS® Naturally active

As a 100% organic soil additive, PERLHUMUS® is characterized above all by its high cation exchange and pH buffer capacity. This leads to the demonstrably positive effects on plant growth and health as well as improved resistance to stress factors. PERLHUMUS® is very active and can be easily absorbed from the root. The high carbon content promotes beneficial soil organisms.

Outstanding properties:

minimizes soil salinization
- keeps the soil pH neutral
- increases root growth
- loosens compacted soils
- unlocks nutrients
- accelerates and increases the germination rate

Application & effort

The natural soil improver PERLHUMUS® can prove its outstanding properties in almost all areas of application of classic gardening and landscaping.

POWHUMUS® Quick success and long lasting effect

Quick success and long lasting effect

POWHUMUS® is a bioactive growth promoter and soil improver with an 85% concentration of humic acids, particularly suitable for sandy and clay soils. It can be easily transported in a finely granulated, crystalline form. Since POWHUMUS is 100% water-soluble and works both in the soil and through the leaves, areas that have already been planted can be supplied without any problems. Tree nurseries can also benefit from these opportunities.

Outstanding properties:

improves the plant quality
- binds pollutants
- reduces stress and drought
- increases root growth
- increases the efficiency of fertilizers
- When sprayed on, it acts as UV protection

Application & effort

Typical areas of application include leaf applications, soil applications, seed treatments, heavy clayey soils, light sandy soils, outdoor crops, forestry and the entire tree nursery sector.

Compo Baumkraft®

Compo Baumkraft® tree cure for trees

The living conditions in the city are often not optimal for the growth of trees: sealed areas restrict the water supply, underground pipes restrict the growth of roots. Such stressed and weakened trees are susceptible to diseases and pests. As a result of the reduced vitality, the foliage on the crown is thinning, twigs and branches die off.


In addition to a regulated water supply, fertilization is a decisive factor in maintaining the desired functionality of the tree. COMPO Baumkraft® Volldünger ensures the need-based supply of nutrients. The high potash and magnesium content as well as the wide range of micronutrients promote vitality and vigor without causing mass growth.

Prevent salt damage

The road salts used in winter deteriorate the soil structure and the salt load on city trees increases. The soil silts up and lets in less air and water. Instead, sodium and chloride ions increasingly reach the leaves via the roots, where, depending on their concentration, they can cause severe damage: leaf litter, late budding, necrosis. A need-based supply of nutrients in advance strengthens the resistance of the trees. An impending salt shock is countered with fertilization in spring (if possible immediately after the dew phase): The Baumkraft® nutrients can occupy the soil colloids in good time and be absorbed by the roots instead of the salt ions. The tree remains healthy and resilient.


- Supply of essential nutrients
- Improvement of the soil structure
- Activation of root growth
- Optimization of the water balance
- Increasing the stress tolerance
- Exchange of damage


COMPO Baumkraft fluid®

COMPO Baumkraft fluid® is a liquid special fertilizer for trees with important main and trace nutrients. The nutrients are in dissolved form and can be immediately absorbed by the roots. The tree-appropriate nutrient ratio ensures a healthy diet and increases the resistance to environmental pollution. The trace nutrients are in chelate form, i.e. organic bonds, and are protected from being laid down.

Recommendations for use: Baumkraft® fluid (6 + 5 + 11)

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COMPO Floranid® Baumkraft

COMPO Floranid® Baumkraft

Floranid Baumkraft is a long-term complete fertilizer with an ideal nutrient ratio for trees in the city. The high potassium and magnesium content as well as the broad traces of nutrients promote vitality and vigor without causing mass growth.

Recommendations for use: Floranid® Baumkraft (9 + 5 + 20 + 4 + Bacillus subtilis)

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A top product of the 3rd or 4th generation, such as Osmocote Exact or Exact DCT, is not required in all cultivation situations for the best cultivation results. A low partial supply, an application as a top dress or a basic supply on basic beds places different demands on a coated permanent fertilizer than a point dosage, high dosage, full supply or crops under extreme conditions such as e.g. B. high temperatures. In such cases, however, the tried and tested Osmocote coating technology should not be dispensed with. With Osmocote Pro, ICL Specialty Fertilizers offers an ideal alternative for these requirements.

The best from the 2nd generation

Osmocote Pro has proven its superiority among the coated permanent fertilizers of the second generation in numerous comparative tests. Osmocote Pro combines the proven Osmocote technology with an excellent price-performance ratio. The main features of Osmocote Pro are high analyzes, defined duration of action and a complete, highly effective micronutrient package.

OSMOCOTE PRO 3 - 4 months

19-9-10 + 2MgO + TE
Osmocote Pro 3-4M is especially suitable for partial storage in the nursery and perennial area as well as for ornamental crops with short cultivation times.

OSMOCOTE PRO 5 - 6 months

19-9-10 + 2MgO + TE
Osmocote Pro 5-6M is especially suitable for early summer potting in the nursery and perennial area as well as for crops with a medium cultivation time.

- 100% coating of NPK, magnesium and trace elements
- Even nutrient delivery over the entire duration of the effect
- Proven Osmocote coating technology
- Complete micronutrient package
- Increasing the stress tolerance
- Good price / performance ratio


Application rates OSMOCOTE Pro

For substrate admixtures, we recommend an application rate of 5 kg / m³ of Osmocote Pro 3-4M | 5-6M

Nutritional requirements low (3-4 / 5-6) medium (3-4 / 5-6) high (3-4 / 5-6)
Nursery 1.5-2 g / l / 2-2.5 g / l 2-3 g / l / 3-3.5 g / l 3-4 g / l / 4-4.5 g / l
Potted plants 1.0-2 g / l / 2-3 g / l 3-4 g / l / 3-4 g / l 3-4 g / l / 4-5 g / l
Bedding plants 1.5-2.5 g / l / 2-3 g / l 2.5-3.5 g / l / 3-4.5 g / l 3.5-4.5 g / l / 4-5.5 g / l




Through the use of our coated slow-release fertilizers, nutrients are oriented towards plant growth and released evenly over the period of action. In this way, a needs-based nutrition of the plants is achieved.

Premium long-term fertilizer for lawns

Therefore, the ICL Landscaper Pro lawn fertilizer is the perfect "in between product" for the lawn. With a unique coating for a long-term supply of nutrients.


- Intense effect
- Good starting effect due to high nitrogen content
- Can be used throughout the season
- For a strong sward

Recommended application period: mid-February - mid-August
Recommended application rate: 35 g / m²

Application note

Use on dry lawn, subsequent irrigation improves penetration into the scar and accelerates the start-up effect. Spread after mowing to avoid being picked up by the mower.

Optimal water management

ICL wetting agents belong to the latest generation of wetting agents. They are able to guarantee the wettability of the root zone over a longer period of time. This is possible thanks to surface-active substances in three different chain lengths, which, similar to slow-release fertilizers, are broken down in different periods of time.

This can last for up to 20 weeks. The multi-matrix effect is made possible by the different chain lengths. The water can not only penetrate into the surface or felt layer, but deeply moisten the entire root zone.

Purchase ICL Landscaper Pro < / p>


H2Pro AquaSmart

- Distributes the water evenly in the upper soil profile
- Makes water-repellent areas accessible to water again
- Significantly reduces the need for irrigation
- Nutrients are more readily available for the roots again

Application note

One liter of H2Pro Aquasmart is sufficient for approx. 200 L of watering solution, which is suitable for surface applications or for watering trees.