Long-term fertilizer: effect, composition & application

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A slow release fertilizer makes fertilizing easier and more comfortable. But what makes the right long-term fertilizer? And when and how do you use it?

Plant is fertilized
Long-term fertilizers release nutrients with a delay over months [Photo: Africa Studio / Shutterstock.com]

Long-term fertilizers, permanent fertilizers or depot fertilizers are called fertilizers that have been specially developed for horticulture. Due to special mechanisms, these fertilizers show a long-lasting effect. But what distinguishes such long-term fertilizers and how do they work?

contents

  • Effect and properties of organic long-term fertilizers
  • Effect and properties of long-term mineral fertilizers
  • Organic slow release fertilizers
  • Long-term mineral fertilizers
    • Wrappings
    • Forms of nitrogen
    • Nitrogen stabilizers
  • Use slow release fertilizer: when, how & how much?
    • When to use slow release fertilizers?
    • How long does slow release fertilizer work?
    • How do you use slow release fertilizers?
  • Long-term fertilizer for conifers, lawns, etc.
    • Long-term fertilizer for flowers
    • Coniferous slow release fertilizer
    • Long-term fertilizer for potted plants
    • Slow release lawn fertilizer

Long-acting fertilizers basically work with different mechanisms that can extend the duration of their effects. You can find more about the mechanism of action and the properties of slow release fertilizers below.

Effect and properties of organic long-term fertilizers

Organic long-term fertilizers get their permanent effect from the fact that the nutrients are firmly bound. This means that the nutrients are not directly available to the plants and must first be broken down by microorganisms in order to become available to the plants. This digestion by microorganisms is also dependent on the heat of the soil, the moisture and the soil air.

Man sprinkles fertilizer in the garden
Organic slow release fertilizers are a very good choice for your own home garden [Photo: Simon Kadula / Shutterstock.com]

Of course, this digestion does not take place overnight, which is why organic fertilizers work slowly and mildly. Due to this mode of action, which not only strengthens the plants, but also actively promotes healthy soil life, organic slow-release fertilizers are a very good choice for your own home garden.

Effect and properties of long-term mineral fertilizers

In contrast, long-term mineral fertilizers work with different mechanisms. This includes wrappings as well as slow-acting forms of nitrogen or stabilizers, which can significantly extend the duration of the effect. We will explain these mechanisms to you in more detail in the section on long-term mineral fertilizers. With many mineral fertilizers, the plants suddenly receive a large amount of nutrients and then have to wait for the next fertilizer. There is also the risk that the nutrients will be washed out and thus lost. Long-term fertilizers contain nitrogen, phosphorus, potassium and often other nutrients such as magnesium, iron and, in small amounts, the equally important trace elements. They are perfectly matched to the plants.

Organic slow release fertilizers

Organic fertilizerwhose nutrients are organically bound do not actually belong to the permanent fertilizers in the strictest sense. With this type of fertilizer, the release of nutrients depends on the composition, the biological activity of the soil organisms and the amount applied. The humidity and the temperature in the soil also have an influence. These factors also influence the soil organisms that digest the nutrients. Organic farm manures include manure and liquid manure, organic commercial fertilizers include, for example Horn shavings, guano or sheep wool.

Plantura range of organic fertilizers
Our Plantura organic fertilizers with long-term effects strengthen your plants and at the same time promote healthy soil life

The long-lasting effect is due to the fact that the nutrients in organic fertilizers cannot be directly absorbed by the plants, as with many mineral fertilizers. The nutrients must first be digested in order to be available to the plants. This results in a longer effect that is also milder. That is why they are suitable for the long-term supply of nutrients to plants - for example our mainly organic ones Plantura organic fertilizer.

Long-term mineral fertilizers

Long-term mineral fertilizers are endowed with a longer duration of action due to the mechanisms already mentioned above. Using special coatings and stabilizers, the fertilizers release their nutrient salts relatively slowly and thus guarantee an effect for months. These nutrient salts are directly available for the plants after they have been released from the granules; only the release is slowed down.

Wrappings

All fertilizers that have “Cote” in their name have a permanent effect, as they are covered with organic and biodegradable layers. In the middle are the water-soluble nutrient salts that must first penetrate this shell. The thicker the cover, the longer the effect of the slow release fertilizer, because the nutrient salts only get through the cover slowly. It is also possible that the fertilizers are coated with sulfur. Such a sulfur shell also slows down the release of nutrients and thus guarantees the prolonged effect of the fertilizers.

Forms of nitrogen

Slowly flowing forms of nitrogen are often used, which guarantee a longer effect. Often these nitrogen forms have a poorer solubility or the conversion by microorganisms takes longer.

Earth with earthworm
Organic long-term fertilizers must first be broken down by microorganisms, but are better for soil health [Photo: photographyfirm / Shutterstock.com]

The following forms of nitrogen are often used in slow release fertilizers: urea formaldehyde, CD urea (crotonylidene diurea) or IB urea (isobutylidene diurea).

Nitrogen stabilizers

Stabilizers prevent the nitrogen from mineralizing too quickly - the conversion of ammonium to nitrate is thus slowed down. This is achieved by inhibiting the Nitrosomonas bacteria, which are not harmed in the process. Nitrosomonas cause the first step of nitrification, i.e. the conversion of organically bound nitrogen or ammonium to nitrate. Such stabilizers include DIDIN and ENSAN.

Summary of slow release fertilizers:

  • The long-term effect of long-term mineral fertilizers is guaranteed by mechanisms such as coatings and stabilizers
  • Nutrients are released slowly
  • Once released, the nutrients are immediately available to the plants and do not have to be digested as is the case with organic long-term fertilizers
  • Granulated fertilizers can be easily applied
  • Organic long-term fertilizers have a milder effect than mineral ones
  • Organic long-term fertilizers must first be broken down by microorganisms, but are better for soil health
  • The long-term effects range from three months to a year

Use slow release fertilizer: when, how & how much?

The effects of slow release fertilizers are very different, depending on the products used. The exact duration of action of commercial fertilizers can usually be found on the packaging and the product description.

When to use slow release fertilizers?

In principle, you cannot name a generally perfect time to fertilize. This always depends on the fertilizer used and the nutrient deposits in the soil. In principle, of course, fertilization in spring is a good idea to guarantee a good start to the gardening year.

Plant grows and is fertilized
The perfect time to fertilize depends on the fertilizer used and the amount of nutrients in the soil [Photo: matkub2499 / Shutterstock.com]

You can use a slow release fertilizer from the beginning of the vegetation phase, even from February (when the soil has thawed). This means that your plants can go into the vegetation with full power and are optimally supplied during their development. Depending on the duration of your long-term fertilizer, one dose in the spring is sufficient. However, you may also have to resort to fertilizer again if the effect is limited to three months, for example. It can be used from spring to late summer.

How long does slow release fertilizer work?

The duration of action of such a permanent fertilizer differs considerably. Long-term fertilizers can have an effect of three months to a whole year, depending on the providers and the products used. You can find information about this on the product packaging, but note that the duration is usually calculated for days at 21 ° C. This means that a fertilizer with an effect of three months is consumed and decomposed faster at temperatures above 21 ° C - consequently the duration of the effect is shortened.

Here is a brief overview of the duration of action of different long-term fertilizers:

  • Long-term fertilizers with sheep's wool work for around five months
  • Osmocote fertilizers work for up to six months
  • Long-term fertilizers with horn shavings work for at least three months
  • Long-term mineral fertilizers work for a period of between three to six months

How do you use slow release fertilizers?

The depot fertilizers do not differ in their application from others mineral fertilizers. You should apply them evenly to the areas to be fertilized and work them in lightly. It is best to use long-term fertilizers for new plantings and simply add the fertilizer to the planting hole.

Planting hole with fertilizer
The slow release fertilizer can simply be added to the planting hole [Photo: Eag1eEyes / Shutterstock.com]

With window boxes and potted plants, you simply mix the slow release fertilizer with the potting soil and then place the plants in the soil-fertilizer mixture.

Use slow release fertilizer summary:

  • Apply slow release fertilizer evenly
  • These fertilizers are particularly suitable for new plantings
  • The slow release fertilizer is simply mixed with the potting soil
  • Our mainly organic fertilizers are an alternative to long-term mineral fertilizers Plantura organic fertilizer represent

Long-term fertilizer for conifers, lawns, etc.

Many different plants can be found in our gardens, which of course also have very different needs. There are also different products with regard to long-term fertilization. Here we explain the fundamental differences between these permanent fertilizers.

Long-term fertilizer for flowers

We expect our flowers to show their most beautiful blooms for us. But that only works if they have enough nutrients to grow and develop properly. If you are already using a slow release fertilizer when planting, you will save yourself laborious re-fertilization later. The long-term fertilizer simply comes into the soil at the beginning of the growing season and, depending on the duration of the effect, you should fertilize again in summer. For flower boxes, fertilizer sticks are also ideal as a long-lasting gift. Long-term flower fertilizers, like conventional flower fertilizers, should contain nitrogen, phosphorus and potassium as well as trace nutrients such as calcium and magnesium for the leafy green. The need depends on the respective flowers and on whether they are heavy or weak consumers.

Before planting, mix the potting soil with the fertilizer [Photo: Bochkarev Photography / Shutterstock.com]

Our Plantura organic flower fertilizer represents an optimal alternative made from predominantly organic raw materials. This flower fertilizer has an NPK ratio of 4 - 2 - 7 and optimally supplies your blooming darlings with nutrients. For example, for flower boxes, use 4 to 6 grams per liter of flower fertilizer before planting. For every further fertilization, we recommend applying 4 grams per liter.

Coniferous slow release fertilizer

The use of long-term fertilizers is particularly worthwhile when replanting trees and bushes. This is simply added to the planting hole so that the conifers are well supplied with nutrients while they should take root and begin their growth. Make sure, however, that the conifer fertilizers contain magnesium, in addition to nitrogen, phosphorus and potassium, because a deficiency in this nutrient often leads to conifers turning brown. Then often only one treatment helps Epsom saltto make up for the shortage. In addition, the fertilizer used should also be low in chloride, because conifers are often sensitive to increased chloride contents.

Long-term fertilizer for potted plants

Long-term fertilizers are also particularly suitable for plants in pots or balcony boxes. When filling your pots, simply mix the slow release fertilizer with your potting soil and place the plants in the substrate as usual. Another variant for long-lasting fertilization would be to use fertilizer sticks. More about the application of Fertilizer stick you can also find out here in our special article. For potted plants, we recommend our Plantura organic universal fertilizer. For indoor plants, simply use 3 to 5 grams per liter of pot volume when replanting and your favorite potted plants are optimally taken care of.

Slow release lawn fertilizer

A long-term effect is of great advantage, especially for the lawn, because it can prevent sudden growth and guarantee an even development of the lawn area.

Our Plantura organic lawn fertilizers with long-term effects provide your lawn with the nutrients it needs

Long-term fertilization is just the thing for this, because the nutrients are not released all at once, but rather continuously. This gives you optimal growth and allows you to enjoy your green spaces. If you're still after a Organic autumn lawn fertilizer or Organic lawn fertilizer look, why not use our Plantura organic lawn fertilizers.