Soil sampling, not guesswork: plan now for 2027
Plan next season after the harvest: combine 10 to 15 subsamples into a representative soil sample, keep land uses separate and test before applying lime or fertiliser.
A cleared bed can invite quick autumn decisions: lime it, feed it, dig it over. A better first step is often a simpler one. A carefully collected composite sample provides the basis for a meaningful laboratory assessment for next season.
Further reading: soil sampling in the gardening magazine
The German-language Pflanzen wunderschön – issue 12 covers soil sampling alongside other winter topics. Any historical dates and competitions in the magazine are not current offers.
View issue 12Why autumn can work well
Once crops have been cleared, it is easier to define separate areas. The Bavarian Garden Academy recommends late autumn, after beds have been cleared, as a suitable time to sample – before autumn soil cultivation and fertilising. Early spring is another option. The key points are to avoid sampling immediately after fertiliser, compost or lime has been applied, and not to sample extremely wet or parched soil.
Four steps to a representative composite sample
- Define the area. Combine only ground with the same use and similar soil. Vegetable beds, lawns, fruit trees, flower beds and acid-loving plant beds should be sampled separately.
- Choose 10 to 15 points. Distribute them evenly across the area. Avoid edges, paths and the immediate vicinity of the compost heap.
- Keep to one depth. The laboratory’s instructions take priority. For German home gardens, the Chamber of Agriculture of North Rhine-Westphalia gives examples of 0–25 cm for vegetable beds and 0–10 cm for lawns. For fruit trees, 0–30 cm and 30–60 cm are analysed separately.
- Mix and label. Thoroughly combine all subsamples in a clean bucket. Put around 500 g in the specified bag and clearly note the land use, sampling depth and date.
| Area | Example depth from LWK NRW | Important |
|---|---|---|
| Vegetable bed | 0–25 cm | One uniformly used area |
| Lawn | 0–10 cm | Do not mix with bed soil |
| Fruit trees | 0–30 and 30–60 cm | Submit depths separately |
These depths are regional examples. Always follow the instructions from the laboratory carrying out your analysis.
What pH alone cannot tell you
A pH value is not a complete feeding plan. Target ranges vary with soil type and crop, while acid-loving plants need separate assessment. Only the combination of laboratory results, land use and a fertiliser recommendation can show whether lime or a particular nutrient is needed at all. An autumn application made “just in case” can push an already adequate or high nutrient level even further.
Three common mistakes
- Taking a single spadeful: it does not reliably represent the whole area.
- Mixing different uses: lawns and vegetable beds have different rooting zones and target values.
- Feeding or liming before the result: that removes the main advantage of testing.
