Frequently asked questions

Natural peat moss is widely used in professional horticulture because of its ability to balance water retention, air capacity, and nutrient management. Its physical structure can be selected to suit different crops and growing systems.

Sphagnum peat moss has a naturally low nutrient content, stable pH characteristics, and a uniform structure. This allows growers to manage fertilization and pH more precisely according to crop requirements.

Natural peat moss can be supplied in different structures and particle sizes, from fine material to coarse fractions. Different fractions provide different levels of water retention, drainage, and air capacity.

Fine peat fractions provide higher water-holding capacity and improved retention of water-soluble nutrients, making them suitable where greater moisture availability is required. Coarser fractions increase air-filled porosity, improve drainage, and help maintain a more open root-zone structure, making the choice of fraction dependent on crop requirements and the cultivation system.

Peat products should be stored in a cool, dry place and protected from direct sunlight and rain. We recommend keeping pallets below approximately 25 °C where possible and following a first-in, first-out storage system.

Compressed peat moss should be loosened gradually and with minimal mechanical force to preserve its original particle structure. This is especially important for coarse fractions, where aggressive mixing, grinding, or high-speed equipment can break down larger peat particles and increase the proportion of fines, changing the intended air and water characteristics of the material. Where possible, equipment should be selected specifically for gentle loosening rather than intensive mixing. For smaller quantities, we recommend loosening the peat by hand on a clean concrete surface using a fork or large shovel, allowing the material to open up without unnecessary structural damage.

The cellular structure of sphagnum peat moss creates a balanced pore system that supports both water retention and air availability in the root zone. By selecting the appropriate peat structure and fraction, the balance between moisture-holding capacity, drainage, and aeration can be adjusted to suit different crops and cultivation systems.

Not necessarily. Changes in substrate pH during cultivation are often influenced by irrigation water quality and the type of fertilizer used rather than by the peat itself. Nitrate-based fertilization and harder water may increase pH, while ammonium-based fertilization and softer water may reduce it, so regular monitoring of irrigation water, fertilization, and substrate pH is important throughout the growing cycle.

Milled peat provides a more uniform, finer structure and typically offers higher water-holding capacity. Sod peat consists of larger, more stable particles that increase air-filled porosity, improve drainage, and help maintain structural stability over longer cultivation periods. The appropriate type depends on the crop, container size, and required balance between water retention and aeration.

Compressed Sphagnum Peat Moss may occasionally develop a temporary odor after prolonged transport, particularly under warm conditions with limited oxygen. This can result from natural anaerobic microbiological activity inside the compressed material and does not necessarily indicate a quality issue. Loosening and aerating the peat after opening allows trapped gases to dissipate and typically restores normal conditions before use.

Fen peat and raised bog peat come from very different raw material. Fen peat is harvested from nutrient-rich (eutrophic) bogs and is made up of many kinds of reeds, sedges, grasses, birch and pine. Its age varies widely, its nutrient content is irregular, and it often has a high salt content and an unpredictable, frequently high pH. It is usually heterogeneous.

Raised bog peat comes from nutrient-poor (oligotrophic) bogs and consists mainly of sphagnum moss. It forms in waterlogged, oxygen-poor conditions over a long humification process, from lightly decomposed white peat to more decomposed black sphagnum peat. The sphagnum cell structure stays intact, the nutrient content is low and the pH is stable, so nutrition and pH can be set precisely with fertilizer and limestone. Because it is almost pure sphagnum, its physical properties are very consistent. It is rich in humic acids, which promote root growth, and it is free of weeds, nematodes and plant pathogens.

No Nordagri product contains plant-pathogenic nematodes. Peat can contain saprophytic nematodes, which have no mouth stylet and cannot damage living plants; they are found in sphagnum peat all over the world. Our raw peat goes through strict laboratory checks, quality management is based on the RHP standard, and national import and export inspections and phytosanitary certificates confirm that the products are free of pathogenic nematodes.

Raised bog peat is naturally very clean. It has a low nutrient content and a low pH, and a waterlogged bog only supports specially adapted plants, so common field crops cannot grow there and pests and diseases cannot establish. Peat taken from agricultural land has to be disinfected; raised bog peat does not, which is a clear economic and ecological advantage. Nordagri’s quality management monitors pests and diseases regularly, confirmed by phytosanitary certificates.

Disinfection can even do harm: it kills beneficial microorganisms and removes the natural suppressive effect that helps protect plants against pathogens.

Most Nordagri products are made from white peat; some have black peat added. The choice depends on the crop and the irrigation method. Peat is classified on the von Post decomposition scale from H1 to H10. Our lightly decomposed white peat is H2-H5. Moderately decomposed white peat (H4-H6) is used for specific purposes such as propagating young vegetable plants: it is darker and holds water well. Black sphagnum peat (H7-H10) is more decomposed and is used only where high water retention is needed.

Colour follows the degree of decomposition, although peat from older bogs can look darker at a similar level. Older bogs generally also give a more stable peat structure.

The 250 L bale is compressed so it is easier to handle and transport, for our staff and for growers. The substrate volume is measured according to the European standard EN 12580 and checked continuously during filling in the factory. The volume is printed on every bale.

Raised bog peat combines economic, chemical, physical and biological properties that give it more advantages than any other growing medium. Its uniformity and ideal properties are what growers need for the best results and the highest crop security. Modern cultivation follows fixed routines for fertilization, irrigation and crop protection, and a substrate that stays stable in structure, nutrient supply and pH is what makes those routines work.

Fine peat: finer structures store more water and water-soluble fertilizer, while coarser structures give more air capacity. Seedlings can be grown in a fine product; pot plants do best in a mix of surface-milled peat and sod peat for good drainage and physical properties.

Sod peat: gives the substrate a stable framework and air capacity. Together with peat fibres it builds the substrate’s structure, and its intact cells still hold water and fertilizer. The better drainage lets sensitive root systems develop.

Peat fibres: made from partly decomposed cotton grass (Eriophorum), they give excellent structural stability, move water through the substrate and improve drainage.

Not necessarily. Peat fibres help drainage by moving water. With too much fibre the substrate first looks soft and airy, but the strong drainage washes finer particles to the bottom of the container, which causes silting. A high fibre content therefore cannot replace sod peat in a well-balanced growing medium.

Our raw material comes from our own peat fields, so the quality of Nordagri products is very consistent. Our recipes are used by growers around the world, and fertilizers and additives are carefully controlled and tested.

• High-quality products for reliable crop results
• Production based on strict quality schemes
• Laboratory checks on every production batch before dispatch, with full traceability for every batch and order
• Reliable supply all year round
• Technical support from Nordagri’s international network
• Effective fertilizer solutions, specific trace-element fertilizers and a wetting agent for high crop security

Compressed peat substrate should be loosened gradually and with minimal mechanical force to preserve its original structure. This is especially important for coarse substrates, as intensive mixing, grinding, or high-speed equipment can break down larger peat particles and increase the proportion of fines, changing the intended physical properties of the substrate. Appropriate equipment should therefore be selected for gentle loosening before use.

Peat substrates should be stored in a cool, dry, and protected environment, away from direct sunlight and precipitation. A first-in, first-out stock rotation is recommended, and pallets should preferably be stored below approximately 25 °C to help preserve product characteristics during storage.

The substrate should be filled and lightly compacted to provide good contact between the root system and the peat without excessively reducing air space. Irrigation should follow immediately after potting or transplanting to ensure proper root-zone contact, while young plants should not be positioned too deeply because further settling can occur after watering and compaction.

Finer peat structures generally retain more water, while coarser structures provide greater air capacity and drainage. Selecting the appropriate structure therefore depends on the crop, pot size, irrigation strategy, and required balance between moisture retention and root-zone aeration.

This effect, often referred to as silting, can occur when a substrate contains too high a proportion of fine particles for the chosen container or when irrigation is excessive. Fine material may migrate toward the bottom of the pot, reducing oxygen availability in the root zone. For longer-term crops, a structure with a higher proportion of sod peat can help maintain better aeration and structural stability.

Irrigation should be matched to the substrate structure, crop requirements, and stage of development. Water should be applied evenly and in a controlled manner, allowing the substrate to re-aerate between irrigation cycles while avoiding both prolonged saturation and excessive drying. For best results, irrigation is generally carried out earlier in the day, with water temperature adjusted where sensitive crops require it.

Changes in pH during cultivation do not necessarily indicate a substrate quality issue. Irrigation water quality and fertilizer composition are important influences: nitrate-based fertilization and harder water can increase pH, while ammonium-based fertilization and softer water can lower it. Regular monitoring of the crop, irrigation water, and substrate is therefore important throughout the growing period.

Representative sampling is essential for meaningful pH and EC measurements. We recommend collecting material from multiple pots and, for packaged substrates, taking samples from different positions within bags and pallets. The collected material should then be mixed uniformly before testing to provide a representative sample.

The effectiveness of a wetting agent depends strongly on storage conditions. Exposure to direct sunlight and significant temperature fluctuations can accelerate degradation; it is generally expected to remain effective for around 6-8 months, although it may decline earlier under unfavorable conditions. Wetting agents are primarily intended to improve initial rewetting during the first weeks of cultivation.

Initial fertilizer incorporated into a peat substrate provides a starting nutrient supply rather than nutrition for a fixed period. Its availability depends on factors such as crop requirements, irrigation and leaching, substrate characteristics, water quality, and growing conditions. Professional growers should monitor crop development and substrate EC and adjust supplementary fertilization according to actual plant demand.

Pure peat is up to 98 % organic matter, and mould is attracted to organic material. To turn peat into a growing substrate, lime and fertilizer are added, which also makes it easier for microbes to live. Saprophytic fungi and bacteria, which feed on dead plant material, and airborne spores that are always present can then settle in the peat.

Open packs with visible mould and mix them thoroughly so they get as much air as possible; the mycelium shrinks quickly once aerated. These fungi are entirely saprophytic and do no harm to the crop.

In the greenhouse, humid conditions favour fungal growth on the substrate surface, usually from airborne spores. Keep the environment drier and make sure substrate and crop are well aerated: irrigate so the surface can dry out, and lower the relative humidity where possible. No fungicide on the market works well against saprophytic fungi, and fungicides have little effect on soil-borne pathogens.

Nordagri offers a wide range of recipes for different needs, and choosing the right recipe for each crop and nursery is the basis of a successful crop. If a recipe turns out too coarse or too fine for your nursery, contact your Nordagri sales contact. Based on your crops, pot sizes and growing conditions, they will recommend a better-suited product from the range.

Algae spores are always present in the environment. Common sources are irrigation water, hoses and pipes, greenhouse benches and structures, and wind from the surroundings. Algae need a pH of 5-7 (they die at pH 4), nitrate, phosphate and CO₂, free water (especially on horizontal surfaces), warmth, high relative humidity and shade.

To counteract algae growth:

• cover rainwater tanks and add oxygen to rainwater to drive out CO₂;
• filter irrigation water;
• keep the crop as dry as possible, for example with a coarser substrate for better drainage and air;
• use as little water as possible inside the greenhouse, ventilate well and lower the relative humidity;
• reduce shading where possible and lower the risk of condensation;
• repair leaking roofs and pipes, and keep the greenhouse clean;
• cover seeds with sand or vermiculite where the crop allows;
• use an algaecide only as a last resort, as it is toxic.

Fungus gnats go through four stages, egg, larva, pupa and adult, in about 21 days, with many generations a year. All stages live close to moist, decomposing plant material, algae and fungi, and a moist substrate surface is an ideal place to lay eggs. Infestations can occur in nurseries, greenhouses and indoor growing spaces. Because most of the insect’s life is spent as a larva or pupa in the substrate, control focuses on these stages rather than on the short-lived adults.

How to control them:

• avoid overwatering, improve drainage and let the substrate dry out sufficiently;
• remove standing water and fix leaks;
• remove breeding places such as moist grass clippings, immature compost, organic fertilizers and mulch;
• screen windows and doors;
• use yellow sticky traps to monitor and reduce the population;
• treat with Steinernema nematodes.

Finer substrates generally hold more water, while coarser substrates hold less water and more air. Make sure the substrate and your irrigation system match; the substrate composition can also be adjusted. After planting, wait until the root system has developed before watering heavily. Contact your Nordagri sales contact if you need further advice.

Nordagri product leaflets describe the typical applications and the standard range of recipes. Our sales partners will recommend a recipe after discussing your specific requirements with you.

Contact your Nordagri sales partner directly with your request, whether it is for specific crops, a new market segment or a particular question.

Every cell needs the same amount and composition of substrate at the same compaction, so filling and compaction must be very even. Standard working procedures and, where possible, automated filling improve uniformity, and an evenly filled and compacted substrate gives even germination, even water management and uniform crop development. Nordagri recipes with a higher share of sod peat make homogeneous filling easier. In fully automated systems, weigh the trays after filling to keep filling consistent.

Nordagri Hobby Potting Soil is an all-purpose growing mix developed for everyday home and garden use. It is designed to support strong early growth and healthy plant development throughout the growing cycle.

The potting soil is suitable for a wide range of indoor and outdoor plants, including vegetables, fruits, berries, ornamental plants, bedding plants, and many common houseplants.

Yes. The all-purpose formulation is designed for use with a broad variety of plants grown indoors, on balconies and terraces, or in the garden.

Yes. It can be used for planting and repotting a wide range of common plants. When repotting, choose a suitably sized container and ensure the plant is positioned at the correct depth.

The Hobby range brings experience and knowledge from professional horticulture into products developed for everyday home growing. The focus is on balanced, practical products that are straightforward to use and suitable for a wide range of plants.

The mix is designed to encourage strong establishment during the early stages of growth and support healthy plant development as the plant matures.

Yes. The Hobby range is designed to make everyday planting and plant care straightforward, making it suitable for both experienced home gardeners and people who are just starting to grow plants.

Keep unused potting soil in a cool, dry place, protected from direct sunlight and excessive moisture. Close the packaging after use to help maintain the condition of the product until it is needed again.

That is very unlikely. Nordagri’s peat fields are carefully prepared before harvesting: the top layer is removed, and the field edges are monitored and kept free of weeds. Raw material is checked for weeds routinely. The low pH and low nutrient content of natural peat also mean that only a few specialised plants, such as sphagnum and some sedges, grow on a peat bog, so common weeds cannot grow or spread their seed there. Being naturally weed-free is one of the main advantages of peat.

Weeds usually come from the surroundings, so keep pots, benches and growing areas clean and free of weeds.

No. Peat is almost pure organic matter, and the lime and fertilizer added to potting soil make it easy for harmless moulds from the air to grow on the surface. These fungi live on dead plant material and do no damage to plants. Loosen and mix the soil so it gets plenty of air, and the mould disappears quickly. Keep potted plants in a spot that is not constantly damp, and let the soil surface dry between waterings.

A sapropel biostimulant is produced from naturally occurring freshwater lake sediments rich in organic matter and biologically active compounds. Nordagri’s formulation contains humic and fulvic acids together with naturally occurring nutrients that support plant development and nutrient uptake.

The biostimulant is designed to support root development, nutrient and water uptake, overall crop growth, and yield potential. It can also provide additional support to plants during periods of environmental stress.

The product is intended for a broad range of agricultural crops and can be incorporated into different crop management programs. The appropriate application strategy should be selected according to the crop, growth stage, and local growing conditions.

The product can be used through several application methods, including foliar spraying, seed treatment, in-furrow application, fertigation, and drip irrigation. For large-scale field agriculture, foliar and in-furrow applications can be integrated into existing field operations.

Yes. The biostimulant is designed to work alongside established fertilization programs rather than replace crop nutrition entirely. It is compatible with a wide range of fertilizers and can be incorporated into existing crop management programs.

Sapropel biostimulant is compatible with a wide range of fertilizers, plant protection products, and plant growth regulators. Compatibility and application conditions should nevertheless be confirmed for the specific tank mix and crop program before large-scale use.

The biostimulant can be used at different stages of crop development, beginning with seed treatment and early establishment and continuing through later growth stages. Application timing should be adapted to crop requirements and the objective of the treatment.

For broadacre farming, the main value is its ability to complement an existing crop program while supporting root development, nutrient uptake, crop performance, and yield potential. The liquid format also allows it to be incorporated into application systems already used in commercial field production.

Sapropel is a naturally occurring, fine-grained sediment that accumulates at the bottom of freshwater lakes under low-oxygen conditions. It is formed from decomposed aquatic plant and animal material combined with mineral components and can contain a significant proportion of organic matter.

The biostimulant should be stored and handled according to the technical product instructions, with the container kept properly closed and protected from unsuitable storage conditions. Before large-scale application, the product should be mixed and handled according to the recommended procedure to ensure consistent use across the field.

Yes. It is CE-marked under EU Regulation 2019/1009, the EU Fertilising Products Regulation, and its effect is backed by three years of research and field trials.