Liquid fertilizer: application, properties and advantages

There are many types of liquid fertilizer. Here we inform you about ingredients and application - and how to make liquid fertilizer yourself.

Opinions differ when it comes to the choice of fertilizer - some prefer solid, spreadable granular fertilizers like ours Plantura organic long-term fertilizer, other hobby gardeners swear by the use of liquid fertilizers. In this article we explain the properties and composition of liquid fertilizers, their areas of application and the differences to granular fertilizers.

Liquid fertilizer: properties and composition

Liquid fertilizers consist of individual, pure minerals or a mixture of nutrients. These can be of organic, mineral-organic or purely mineral origin. Liquid fertilizers are usually applied via the irrigation water, but can also be used as foliar fertilizers. This applies above all to micronutrients such as iron or boron, in the form of pure form suspensions. Liquid fertilizers are popular because of a number of advantages:

• Fast effectiveness: Liquid fertilizers are absorbed much faster by plants and can therefore also help with acute deficiency symptoms.
• Variable application: With the irrigation water or with the spray bottle as a foliar fertilizer.
• Nutrients included: Depending on the needs of the plants, the nutrients can be applied in their pure form or as an optimized combination.

Not every form of the nutrient elements is stable or plant available in the liquid form. Some nutrients must be incorporated into a so-called chelate compound for use in liquid fertilizers. The special composition as well as the production and extraction of the nutrients available to plants is also the reason for the often significantly higher price compared to solid fertilizers.

Note Dispose of liquid fertilizer: If you want to dispose of liquid fertiliser, the safest way is to hand it in at a pollutant collection point, ideally in the original packaging. Liquid fertilizers should never get into the sewage system or other bodies of water, since highly concentrated mineral fertilizers in particular are toxic to many aquatic organisms and the environment in general. In the best case, you dilute the liquid fertilizer to a high degree and water beds, shrubs and trees with it in small doses. A compost heap with materials that are difficult to decompose, such as wood chips and plant cuttings, also benefits from a slight nitrogen fertilization, since nitrogen is often fixed here during the composting process will.

Organic organic liquid fertilizer

The raw materials used in the manufacture of liquid fertilizers can be of different origins. For example, liquid manure and manure from animal husbandry contain large amounts of usable nitrogen compounds. Residues from the food or forestry industry can also provide nutrients in the form of recyclable natural materials such as cocoa shells or vinasse. In this case, the nutrient is present in organic compounds. If a liquid fertilizer contains components of mixed origin, then it is called organo-mineral fertilizer. Both simpler and more varied mixtures are also available for organic liquid fertilizers. However, the starting materials of purely organic fertilizers usually contain many trace elements, so that pure NPK fertilizers are rarely found among organic liquid fertilizers.

Our Plantura organic liquid fertilizer are made entirely without animal products and obtain their nutrients from leftovers from food, luxury food and feed production in a resource-saving manner. The Plantura Organic Tomato & Vegetable Fertilizer and Organic flower & balcony fertilizer are purely organic liquid fertilizers, while in our predominantly organic Plantura Organic Citrus & Mediterranean Fertilizer or. Organic room and green plant fertilizer additional micronutrients contain potassium sulfate.

Mineral liquid fertilizers and organo-mineral liquid fertilizers

Another possibility of liquid fertilization is the use of mineral nutrients. For this purpose, the nutrients are extracted from mines or artificially produced in chemical processes. They are then in a very pure form. mineral fertilizers have a very fast effect thanks to their direct plant availability. The disadvantage, however, is that the nutrients in mineral form neither promote nor nourish soil life. In the long run, the nutrient salts pollute the soil, lower the pH value and can lead to salinity. When it comes to dosing, you need a sure instinct, because over-fertilizing – especially with fast-acting mineral fertilizers – can severely damage the roots. A more balanced combination is organic-mineral liquid fertilizers.

Notice: Why do liquid fertilizers never contain calcium? Although calcium is also an essential nutrient, it is not included in liquid combination fertilizers. This is because, to put it bluntly, calcium and phosphorus find each other chemically irresistible. For this reason, calcium is not added to liquid fertilizers. Therefore, you should not fertilize immediately after fertilizing with liquid calcium fertilizer containing phosphorus, but rather allow a few months to elapse between fertilizing. However, calcium can be bought as a pure nutrient for foliar fertilization, which can be used, for example, to combat blossom end rot important is.

Summary: properties and composition of liquid fertilizers

• Mineral liquid fertilizers are made from raw materials that are mined or produced in chemical processes. The result is pure fertilizer salts, which, as a pure substance or in combination, are absorbed extremely quickly by plants.
• Organic Liquid Fertilizer In addition to the main nutrients (nitrogen, phosphorus and potassium), they usually contain other trace elements and promote soil life through the organic compounds they contain. They often use recyclable residues from the food industry and are therefore often classified as significantly more sustainable. That's why we at Plantura also rely on purely organic or primarily organic liquid fertilizers.

Pros and cons of liquid fertilizers

Although liquid fertilizers have many advantages, they also have some disadvantages compared to solid granular fertilizers.

Advantages of liquid fertilizers	Disadvantages of liquid fertilizers
Optimal plant availability	There is a risk of over-fertilization if the wrong dosage is used, since it is fully available immediately
Use as liquid fertilizer or foliar fertilizer	Relatively expensive compared to solid fertilizers
Easier dosing than with solid fertilizers, since the speed of release does not have to be taken into account	No long-term effect, more frequent use in low doses necessary
Often contain additional trace nutrients	Some nutrients are never included in combinations, e.g. B. calcium and phosphorus
When used with the irrigation water, one work step is omitted	No introduction of organic matter to build up humus
Fast treatment possible in case of acute nutrient deficiency	Not a complete substitute for full-fledged organic fertilization

Conclusion: So all in all, the choice between liquid fertilizers and granular fertilizers is mainly a matter of personal preference. Liquid fertilizers can be easily applied over the irrigation water, but must be used frequently (usually every one to two weeks). In the case of granular fertilizers with a long-term effect, two fertilizer applications per season are usually sufficient, for which the granules must be worked into the soil. As a rule of thumb, liquid fertilizers are more recommended for potted and balcony plants, while granular fertilizers are the best choice for plants in beds.

Applying liquid fertilizer: dosage and application

As different as liquid fertilizers are composed, so are their areas of application. Liquid fertilizers can be poured or sprayed onto the foliage as a foliar fertilizer. In the following we give you an overview of liquid fertilization for lawns, vegetables and flowering plants, green and house plants as well as citrus plants.

Application as foliar fertilizer

Plants are able to absorb many nutrients through the leaf alone and thus incorporate them directly into the leaf's metabolism. Younger leaves absorb the nutrients the fastest. Foliar fertilization can be used on almost all plants. However, leaves that are very hairy or covered with a thick layer of wax absorb the nutrient solution much more poorly. Overall, the concentration of nutrients in foliar fertilization is so low that it is only worthwhile for micronutrients such as boron, zinc or iron and for acute deficiency symptoms.

Foliar fertilization should only be carried out at temperatures between 10 °C and 25 °C if the plant's metabolism is not inhibited by either cold or heat. Even in direct sunlight and severe drought, you should not apply foliar fertilization, otherwise burns may occur. Days with overcast skies or the evening hours are best. A low concentration of the fertilizer solution from the outset also offers good protection against this damage. Pour the fertilizer solution into a sprayer and evenly wet the leaves of the plant, just enough to keep the suspension from dripping.

Apply liquid lawn fertilizer

In addition to granular fertilizers to be applied with a spreader, there are often mineral fertilizers on the market Liquid fertilizer for lawns on offer. However, considerable disadvantages arise when fertilizing lawns via the irrigation system. Fertilizing in an aqueous solution not only fertilizes the soil, but also foliar fertilization. The absorption of nutrients is therefore very fast and any deficiency is soon remedied. However, the application must be repeated frequently in order to provide the lawn with sufficient nutrients throughout the season. The application of a solid lawn fertilizer twice a year represents a significantly lower expenditure of time and money. The sole use of liquid fertilizer on lawns is by no means a permanent solution. The risk of liquid fertilizers being washed out over large areas is also significantly higher. We therefore recommend using mainly organic long-term fertilizers in solid form, such as our Plantura Organic Lawn Fertilizer.

Apply liquid fertilizer to vegetables

The application of liquid fertilizer to tomatoes (Solanum lycopersicum) and other types of vegetables is a good alternative to granular fertilization, especially when cultivated in tubs or balcony boxes. The planters are often too small to provide sufficient nutrients from the potting soil alone until the end of the season. Working granules into the planters, which are often heavily rooted, often injures the root system of the plants. Special blends for vegetables often contain higher concentrations of potassium to improve drought resistance and fruit quality. Trace elements are normally available in sufficient quantities in fresh culture substrate and do not have to be added separately.

Our purely organic Plantura Organic Tomato & Vegetable Fertilizer is suitable for all vegetable plants with an increased need for potassium - in addition to tomatoes, for example paprika (Capsicum annum), pumpkin (Cucurbita), cucumber (Cucumis sativus) or zucchini (Cucurbita pepo subsp. pepo convar. giromontiina). It is applied about once a week in a dosage of 15 to 25 ml per 5 l of irrigation water and reliably supplies vegetables with the most important nutrients.

Use liquid flower fertilizers

Annual summer flowers grow and bloom in a short time, often with so many flowers that they need regular fertilization to keep them flowering. Just before and during the flowering period of petunia (petunia), snapdragon (antirrhinum), zinnia (Zinnia elegans) and Co. should therefore start with fertilization. The same applies to perennial flowering perennials and potted plants such as oleander (Nerium oleander), African lily (agapanthus), shrub daisy (Argyranthemum frutescens), hibiscus (Hibiscus) or asters (aster): You already need good basic care that promotes budding in spring. In order to have sufficient resources for the usually lush flowers, you can help out with liquid flower fertilizer from early summer, especially for large plants in small tubs. An organic liquid fertilizer like ours Plantura organic flower & balcony fertilizer, is ideal for fertilizing flowering plants in balcony boxes, tubs and also in beds. It consists of purely biologically produced, animal-free substances and is therefore particularly resource-saving and environmentally friendly.

Apply liquid fertilizer to indoor plants and green plants

Houseplants need more frequent fertilizer than their colleagues in the bed, since they only find a very limited supply of nutrients in their narrow volume of soil. In the case of potted plants, liquid fertilizer via the irrigation water is often the only way to supply essential nutrients outside of repotting. Our primarily organic Plantura Organic room and green plant fertilizer provides nitrogen and potassium for a wide variety of herbs, but also palms and other indoor plants. In addition, the microorganisms contained promote plant health.

tip: The application of liquid fertilizers to ornamental trees and hedge plants in the garden is usually not necessary. Unless it is an acute nutrient deficiency, solid fertilization is a better option here. When fertilizing trees and shrubs, we recommend that you use primarily organic fertilizers in order to To promote soil life and a slower, but longer-term and gentler release of nutrients guarantee. Highly dosed, immediately available mineral fertilizers can even damage woody plants: the suddenly stimulated, rapid growth leads to soft shoot tips and thus to susceptibility to sucking insects and Frost.

Use on citrus plants and Mediterranean plants

citrus plants (citrus) and other Mediterranean plants like the olive (Olea europaea) have an increased need for micronutrients, especially iron (Fe). If the nutrient is missing, iron deficiency chlorosis easily forms, with the youngest leaves and shoot tips turning yellow. In our Plantura Organic Citrus & Mediterranean Fertilizer therefore contain boron, manganese and molybdenum in addition to the main nutrients and iron. Your Mediterranean plants are thus optimally supplied with all the important nutrients during the growth period between March and October. Because we care about the environment, the packaging for our liquid fertilizers is made from 95% recycled plastic (HDPE), with the exception of the dosing cap.

Tip: Sodium is not actually an essential plant nutrient. However, there are some plants that urgently need sodium - these are called halophytes. They include, for example, the sea aster (Aster tripolium), the sea plantain (Plantago maritima) and various sour and sweet grasses (Cyperaceae and Poaceae).

Make your own liquid fertilizer

Adding nutrients in liquid form is not a new idea: making plant manure and extracts for use as plant strengtheners is a very old practice. It is also very gratifying that some of the residents of our gardens, who are notorious for being “weeds”, can make a valuable contribution. the nettle (Urtica) can be fermented into a nutrient-rich broth with little effort. These nettle manure can be diluted in a ratio of 1:10 to 1:20 with rainwater as a fertilizer or sprayed undiluted as a plant strengthener and biological insecticide. Even horsetail (equisetum), Comfrey (Symphytum officinale) and other wild herbs can be processed into liquid plant fertilizers. onions (Allium cepa) and garlic (Allium sativum) can also be used for liquid manure to protect plants from fungal and insect infestation.

In order to obtain plant manure, plant parts are first roughly crushed. Then put this in a lockable container, such as a bucket, and fill it up with rainwater. The sealed, future liquid manure is now placed in a warm place and fermentation begins there. After a few weeks it will be ready. This can be recognized by the fact that the liquid contains hardly any plant parts and has taken on a dark brown, clear colour.

Long-term fertilizers in granular form are an alternative to liquid fertilizers. Although these cannot simply be applied via the irrigation water, they have an effect for several months. all about long-term fertilizer Find out in our special article.