Fertiliser is sold as a general tonic. Agronomically it is a correction for a measured shortfall, and the measurement costs a fraction of a season's worth of product.
What a test reports
A standard laboratory test returns soil pH plus levels of the major nutrients and, usually, organic matter. pH matters independently of nutrient content: outside a workable range, nutrients present in the soil become less available to plants regardless of how much is added.
Why over-feeding backfires
- Excess nitrogen drives soft leafy growth at the expense of flowering and fruiting.
- Nutrients not taken up can leave the site in runoff; several jurisdictions regulate application rates for this reason.
- Salts accumulate in container compost, which is one cause of scorched leaf edges.
Where to get a test
University extension services, national horticultural bodies and commercial laboratories all offer soil analysis. Home kits indicate pH reasonably well but are less reliable for nutrient levels.
This article does not recommend a specific product or brand. Application rates should follow the laboratory's recommendation and the product label, which is a legal document in most markets.
