Liquid fertilizer: application, properties & benefits

There are many variants of liquid fertilizers. 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, 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 as well as 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 mostly applied via the irrigation water, but can sometimes also be administered as foliar fertilizers. This is especially true for micronutrients such as iron or boron, in the form of pure form suspensions. Liquid fertilizers are popular because of some advantages:

• Fast effectiveness: Liquid fertilizers are absorbed by plants much faster and can therefore also provide a remedy for acute deficiency symptoms.
• Variable application: With the irrigation water or with the spray bottle as foliar fertilization.
• Included nutrients: 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 available to plants in the liquid form. Some nutrients have to be incorporated into what is known as a chelate compound for use in liquid fertilizers. The special composition as well as the production and extraction of the plant-available nutrients 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 fertilizer, 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 sewer system or other bodies of water, as highly concentrated mineral fertilizers in particular have a toxic effect on many aquatic organisms and the environment in general. In the best case scenario, you dilute the liquid fertilizer to a high degree and use it to water beds, shrubs and trees in small doses. A compost heap with materials that are difficult to decompose, such as wood chips and cuttings, also benefits from a light nitrogen fertilization, as nitrogen is often trapped in the composting process will.

Organic liquid fertilizer

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

Our Plantura organic liquid fertilizer are produced entirely without animal products and obtain their nutrients from leftovers from food, luxury and animal feed production in a resource-saving manner. The Plantura Organic tomato & vegetable fertilizer and Organic flower & balcony fertilizer are purely organic liquid fertilizers, while ours are predominantly organic Plantura organic citrus & mediteranean fertilizer respectively. Organic indoor & green plant fertilizer additional micronutrients or Potassium sulfate are included.

Mineral liquid fertilizers and organic-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 using chemical processes. They are then in a very pure form. Mineral fertilizers have a very quick effect thanks to their direct availability from plants. However, it is disadvantageous 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 salinization. When it comes to the dosage, you need a sure instinct, because over-fertilization - especially with the fast-acting mineral fertilizers - can severely damage the roots. Organic-mineral liquid fertilizers represent a more balanced combination.

Note: Why do liquid fertilizers never contain calcium? Although calcium is also an essential nutrient, it is not found in combination liquid fertilizers. The reason for this is that calcium and phosphorus, to put it casually, find each other chemically irresistible. For this reason, no calcium is added to liquid fertilizers. Therefore, you should not fertilize calcium immediately after fertilization with phosphorus-containing liquid fertilizer, but rather leave a few months between fertilization applications. However, calcium can be bought as a pure nutrient for foliar fertilization, something that can be used, for example, to combat the Flower end rot important is.

Summary: properties and composition of liquid fertilizers

• Mineral liquid fertilizers are made from raw materials that are extracted in mines or produced using chemical processes. The result is pure fertilizer salts which, as a pure substance or combination, are absorbed extremely quickly by plants.
• Organic liquid fertilizers usually contain other trace elements in addition to the main nutrients (nitrogen, phosphorus and potassium) 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 is why we at Plantura also rely on purely organic or primarily organic liquid fertilizers.

Advantages and disadvantages of liquid fertilizers

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

Benefits of liquid fertilizers	Disadvantages of liquid fertilizers
Optimal plant availability	Risk of over-fertilization in case of incorrect dosage, as it is immediately available
Use as liquid fertilization or foliar fertilization	Relatively expensive compared to solid fertilizers
Lighter dosage than with solid fertilizers, as the speed of release does not have to be taken into account	No long-term effect, more frequent use in lower doses necessary
Often also contain trace elements	Some nutrients are never included in combinations, e.g. B. Calcium and phosphorus
One step is omitted when using it with the irrigation water	No introduction of organic matter for the humus build-up
Rapid treatment possible in the event of acute nutrient deficiency	Not a complete substitute for full organic fertilization

Conclusion: All in all, the choice between liquid fertilizers and granular fertilizers is mainly a question of personal preference. Liquid fertilizers can simply be applied via 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 fertilizers per season are usually sufficient; the granules must be worked into the soil for this. 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 differently 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, vegetable and flowering plants, green and indoor plants as well as citrus plants.

Use as foliar fertilization

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 metabolism of the plant is not inhibited by either cold or heat. Even in direct sunlight and very dry, you should not fertilize the leaves, otherwise burns can occur. Days with overcast skies or the evening hours are best. Even a low concentration of the fertilizer solution from the outset offers good protection against this damage. Pour the fertilizer solution into a sprayer and wet the leaves of the plant evenly and only enough so that the suspension does not drip off.

Use liquid lawn fertilizer

In addition to granular fertilizers that can be applied with a spreader, mineral fertilizers are also often available on the market Liquid fertilizer for lawns on offer. However, there are considerable disadvantages when fertilizing lawns using the irrigation system. Fertilizing in an aqueous solution not only fertilizes the soil, but also fertilizes the leaves at the same time. The absorption of nutrients happens very quickly and a possible deficiency is soon remedied. However, the application must be repeated frequently to provide the lawn with sufficient nutrients throughout the season. Applying solid lawn fertilizer twice a year represents a significantly lower investment of time and money. The sole application of liquid fertilizer to lawns is by no means a permanent solution. The risk of leaching is also significantly higher with liquid fertilizers over a large area. We therefore recommend using primarily 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 vegetables are a good alternative to granulate fertilization, especially when cultivated in pots or window boxes. The planters are often too small to provide sufficient nutrients from the potting soil alone until the end of the season. Incorporating granules into the often deeply rooted planters often injures the roots of the plants. Special mixtures 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 growing media 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, also for paprika (Capsicum annuum), 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 vegetable plants with the most important nutrients.

Use liquid flower fertilizers

Annual summer flowers grow and bloom in a short period of time, often with so many flowers that they need regular fertilization to ensure that they continue to flower. 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 container plants such as oleander (Nerium oleander), African Lily (Agapanthus), Shrub marguerite (Argyranthemum frutescens), hibiscus (Hibiscus) or asters (aster): You already need a good basic supply that promotes sprouting in the spring. In order to have sufficient resources for the mostly lush flowers, liquid flower fertilizer can be used from early summer, especially for large plants, in small pots. An organic liquid fertilizer like ours Plantura organic flower & balcony fertilizer, is ideal for fertilizing flowering plants in window boxes, pots and also in beds. It consists of purely organically produced, animal-free materials and is therefore particularly resource-saving and environmentally friendly.

Use liquid fertilizer on indoor plants and green plants

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

tip: The use of liquid fertilizers on ornamental trees and hedge plants in the garden is usually not necessary. Unless there is an acute nutrient deficiency, fertilization in solid form is the better option here. When caring for trees and shrubs, we recommend that you primarily use organic fertilizers to prevent the To promote soil life and a slower, 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 a susceptibility to sucking insects and Frost.

Use on citrus 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 can easily develop, with the youngest leaves and shoot tips turning yellow. In our Plantura organic citrus & mediteranean fertilizer therefore contain boron, manganese and molybdenum in addition to the main nutrients and iron. This means that your Mediterranean plants are optimally supplied with all the important nutrients during the growing season between March and October. Since the environment is important to us, the packaging of our liquid fertilizers consists of 95% recycled plastic (HDPE) except for the dosing cap.

Tip: Sodium is actually not an essential plant nutrient. However, there are some plants that urgently need sodium - these are called halophytes. They include, for example, the beach asters (Aster tripolium), the beach 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: the production of plant manure and extracts for use as plant tonic is a very old practice. It is also very gratifying that some of the residents of our gardens, who have been decried as “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 fertilizer or sprayed in undiluted form 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 attack.

In order to obtain plant manure, parts of the plant are first roughly chopped up. You then put this in a sealable container, such as a bucket, and fill it up with rainwater. The closed, future liquid manure is now placed in a warm place and begins fermentation there. It will be ready after a few weeks. This can be recognized by the fact that the liquid hardly contains any parts of the plant and has taken on a dark brown, clear color.

Long-term fertilizers in granulate form are an alternative to liquid fertilizers. Although these cannot simply be applied via the irrigation water, they work for several months. All over Slow release fertilizer you can find out in our special article.