Plant protection is legally regulated core content: the eight IPM principles, the requirement for spray certificate in commercial use, mechanical and thermal weed control, and the main pests and diseases a landscape gardener encounters.
Introduction
Plant protection is about keeping pests, fungal diseases, and weeds in check — but today the main rule is that chemistry is the last resort, not the first. The framework is integrated pest management (IPM), and the use of pesticides is legally regulated and requires a valid certificate. A landscape gardener must know both prevention, the non-chemical methods, and the regulations.
IPM — integrated crop protection
IPM (Integrated Pest Management) is a mandatory framework in the EU under Directive 2009/128/EF. The idea is to prevent first, monitor continuously and only control when necessary — and preferably without chemistry. Annex III of the Directive sets out eight general principles:
- 011. Prevent and suppress pests through species selection, healthy and resistant varieties, good hygiene (clean tools, healthy plant material) and balanced fertilising and watering.
- 022. Monitor pests with suitable methods — observation in the field and any warning systems.
- 033. Decide based on monitoring and, if possible, set threshold values whether and when to combat.
- 044. Prefer sustainable biological, physical and other non-chemical methods over chemical ones if they are sufficiently effective.
- 055. Choose the substance as targeted and gently as possible — minimal side effects on humans, beneficial organisms and environment.
- 066. Keep consumption to the necessary: reduced doses, fewer treatments, partial treatment.
- 077. Use anti-resistance strategies — switch between agents with different modes of action to maintain effectiveness.
- 088. Evaluate the result from records (spray log) and own observations, and use the experience going forward.
Spraying certificate and proof
Professional purchase and use of plant protection products requires a personal authorisation from the Danish Environmental Protection Agency (BEK no. 951 of 26/06/2025). For landscape gardeners and greenkeepers there are two: S1 covers all usual application methods and is obtained with the spraying certificate (74 hours). S2 covers hand and knapsack sprayers, granules and wiping and is obtained with the hand and knapsack sprayer certificate (14.8 hours) or on the basis of a spraying licence. The authorisation is listed in the agency's register (MAB), and the dealer checks the number when you buy.
| Requirement | S1 authorisation | S2 authorisation |
|---|---|---|
| Covers | All usual application methods (including those of S2) | Hand and knapsack sprayer, granules, wiping |
| Basic training | Spraying certificate, 74 hours (Annex 2) | Hand and knapsack sprayer certificate, 14.8 hours (Annex 3) — or spraying licence |
| Validity | 4 years from the date of the certificate (§ 5(4)) | 4 years (§ 6(4)) |
| Renewal | Follow-up course, at least 7.4 hours (§ 23, Annex 8) | Follow-up course, 3.7 hours (§ 23, Annex 9) |
| Fee | DKK 230 for the four years (§ 15) | DKK 230 for the four years (§ 15) |
Weed control without chemicals
On paved surfaces and in plantings, many weeds are managed without herbicides. The mechanical and thermal methods are often the first choice — especially on public areas:
| Method | Mode of operation | Suitable for |
|---|---|---|
| Hoe, weeding iron, hand weeding | Mechanical — cuts or pulls weeds up | Beds, small areas, between plants |
| Weed brush (power tool) | Mechanical — brushes weeds and roots from joints | Coatings, joints, kerb stones |
| Gas burner / flame treatment | Thermal — shatters cells by heat | Joints and surfaces (watch out for fire hazard) |
| Steam / hot water | Thermal — boils plant tissue | Fastenings in sensitive surroundings |
| Covering / root protection cloth | Physical — light and growth hindered | New beds, under bark or chips |
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