For a thriving, growing and healthy garden, your plants need sufficient nutrients in the form of fertilizer. If there is a lack of nutrients in the soil, your plants will not grow properly, will not develop flowers, and will be susceptible to frost, disease, and pests. Granted: Proper fertilizing requires a little bit of intuition. That’s why we’ll familiarize ourselves with the most important basics of fertilizing and take a look at which fertilizers are available.
Organic or mineral fertilizer? The difference
In general, we distinguish between mineral or inorganic fertilizers and organic fertilizers. The difference is that mineral fertilizers consist of water-soluble minerals and can be quickly absorbed by the plant with the watering water.
Organic fertilizers consist of animal or plant matter such as horn shavings, manure, natural sheep wool or compost. While organic fertilizers are not as readily available to the plant as mineral fertilizers, they have a much longer duration of action and plant availability in the soil. This means that your plants can get their nutrients from the one application of fertilizer for a very long time. If you grow fruits, vegetables and herbs, you should definitely choose organic fertilizer in organic quality, for example our Bloomify Universal Fertilizer.
Mineral fertilizers are colloquially known as “artificial fertilizers.” In simple terms, they are obtained from fossil raw materials, whereby they are dissolved from their environment, for example rock, in complex processes and chemically transformed so that they can be absorbed by the plant. They are very quickly available to the plant and are thus quickly absorbed by it. This may give a faster result, but the effect wears off quickly and you have to fertilize much more frequently than with organic fertilizers.
Are mineral fertilizers harmful to the environment?
The major disadvantage of mineral fertilizers is that the minerals (especially nitrogen in the form of nitrate) quickly seep into the soil and pollute the groundwater. In the long run, such fertilizers cause acidification of the soil and harm the environment. So it’s more sustainable if you opt for organic fertilizers like compost. However, if you don’t have a compost pile, you can buy compost in bags. You can also often find organic slow-release fertilizers in stores in pellet form, such as those based on sheep’s wool. Our Bloomify fertilizer is such a pellet fertilizer, but plant-based.
You may have heard the term NPK fertilizer before. What is it all about? Quite simply, NPK stands for nitrogen (N), phosphorus (P) and potassium (K). These three substances are the main components of a balanced complete fertilizer that provides your plants with everything they need. Mineral NPK fertilizers, however, should be used with caution to avoid overfertilization. However, organic variants are now also available.
How to fertilize correctly
Less fertilizer is more: it’s the quantity that counts
When fertilizing, you should keep this principle in mind. Unfortunately, a lot of fertilizer does not help much at all, but can mean certain death for your plants if you overdo it. If you have your own garden, a soil test can make sense in advance; depending on the soil conditions, the pH value and the overall nutrient content can vary greatly. However, you can remember the following principle: sandy and loamy soils generally contain fewer nutrients than humus-rich soils and need to be fertilized more frequently. If you feel like it, you can read more about garden soil here.
Test strips are available in stores that make it easy to determine the pH of your soil. Alternatively, you can send a soil sample from your garden to the laboratory for analysis every one to three years. This often saves you not only money, but also fertilizer.
For potted plants and purchased soil, be sure to check if the soil is pre-fertilized. If so, fertilize a little less or less frequently.
How much fertilizer do you need? The right dosage
When fertilizing outdoors, the following applies: If you use ready-made fertilizer, you should orient yourself to the amount of fertilizer indicated on the product. This can vary between manufacturers. Do not use more than indicated.
If you use compost, the rule of thumb is: 3 liters of compost per 1 square meter of garden soil. You can simply work the appropriate amount into the soil with a rake. Important: If you want to mulch in addition, you should first apply the fertilizer and then mulch!
Fertilize potted plants
In the tub on the balcony or terrace, your plants have significantly less soil available than in the open. This means that the nutrients will soon be used up and you will definitely have to fertilize after a while. The frequency and amount depends on whether you choose organic slow-release fertilizer (e.g. compost) or mineral fertilizer. If you use compost, the amount should not exceed 30 percent of the total substrate.
Basically, you should mix compost, or organic slow-release fertilizer in general, into the soil when potting (even with fresh potting soil from the hardware store!). Potting soil from the store is already enriched with nutrients, but organic fertilizers have a long-term effect and therefore take longer to release the nutrients into the soil. This means that they are only available to the plants later.
Do all plants need the same amount of fertilizer?
The appropriate amount of fertilizer therefore also depends on the plant in question. We distinguish between low, medium and high-yielding plants.
Low-growers have low nutrient requirements and can cope with nutrient-poor soils. These include legumes (e.g., peas), most herbs, and radishes.
Medium eaters include many types of lettuce and carrots. They need more nutrients than low feeders, but not as many as high feeders.
Highly nutritious plants, such as peppers, tomatoes, zucchini, cabbage varieties or cucumbers, have high nutrient requirements and need a correspondingly large amount of nutrients.
Important: Plants that need an acidic soil should not be fertilized with compost! These include, for example, strawberries, lavender and blueberries.
The right time
The first fertilizer should be applied outdoors in March, preferably before the first plants sprout. Because: As soon as the growth phase of your plants begins, they naturally need nutrients to develop well. Then fertilize until August – no fertilizer should be applied later so that hardy plants can prepare for the cold. Fertilizing too long into the fall will result in a loss of frost resistance!
The strong growers, for example in the vegetable bed, can receive a second fertilizer application between June and August. If you have to use mineral fertilizers, you should fertilize the first time 4 weeks after planting and then every 1 to 2 weeks, depending on the plants to be fertilized and the product specifications.
In what weather should you fertilize your garden?
In general, it’s best to fertilize in the morning and in dry weather so that rain doesn’t immediately wash away the applied nutrients. This also allows your plants to absorb the nutrients through their roots during the day along with the irrigation water.
With a few exceptions (see above), compost works very well as a universal fertilizer and should simply be worked into the soil in spring or late fall. Slow-release fertilizers, i.e., including our Bloomify complete fertilizer, can also be administered at that time. This gives the soil enough time to absorb and store the nutrients.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
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