Correct application begins with three pieces of information: which product, the plant's growth stage, and what the soil or growing medium already contains. An application amount passed on by word of mouth does not adequately answer these three questions.
Set your objective before adding fertilizer
Record what you want to improve, such as monitoring growth or adjusting an organic input plan. If a plant is weak, check light, water and root condition instead of assuming a nutrient deficiency.
Vermicompost does not replace identifying the cause of plant disease. Nor does the name organic fertilizer mean that any amount is safe.
Read the instructions for the specific product
For container plants, University of Minnesota Extension emphasizes following the fertilizer label and managing watering and drainage. Your choice of application method therefore needs to relate to the specific product and growing system, rather than only the fertilizer category.
- Check the intended use, application method and storage conditions on the label.
- Record the fertilizers already used so that total inputs are not overlooked.
- Do not independently turn soil application instructions into a liquid preparation recipe.
- If suitable instructions are missing, clarify them before applying the product widely.
Monitor a controlled change
When trying a new application method, keep other practices comparable and record the date and amount used. Observe adverse reactions as well as pictures of green plants. An unchanged area offers a better comparison than relying on memories of previous conditions.
This article does not provide one general rate for all plants or recommend replacing all mineral fertilizers simply because vermicompost is added. Effectiveness must be evaluated against objectives, conditions and actual data.
Read more: Is vermicompost suitable? Weighing benefits and limitations; Mixing vermicompost for watering plants: distinguishing extracts, compost tea and leachate.