Lesson 2
Drip irrigation for beds and borders
Drip irrigation is a perforated hose laid on the soil surface or buried 5–10cm down. Water seeps out slowly, directly into the root zone. No evaporation, no wet leaves, no standing with a hose for twenty minutes.
A basic system needs four components: a tap timer, a pressure reducer (most domestic taps run at 3–4 bar; drip systems want 1–1.5 bar), a filter to prevent blockages, and the drip line itself. You can buy kits for £40–80 that include everything. The drip line comes in two styles: porous soaker hose that weeps along its entire length, or inline emitter tubing with outlets every 30–45cm.
Soaker hose works beautifully for densely planted beds — salads, carrots, annual flowers. Inline emitters are better for widely spaced plants like courgettes, dahlias or shrubs, because you control exactly where the water goes. Run the system for 30–60 minutes every morning during dry spells. In clay soil, lean towards shorter, more frequent sessions; in sandy soil, go longer and less often.
The system pays for itself in one summer. Your water bill drops, your plants grow faster, and you can go away for a week without panic.
Common mistakes
- Running the system for 10 minutes — the soil surface wets but roots stay dry
- Laying drip line on top of mulch instead of under it — UV degrades the plastic within two years
- Forgetting the pressure reducer — emitters blow out or spray instead of dripping
- Not flushing the system at season's end — algae and sediment block emitters over winter
Installing a basic drip system
- 1.Attach timer, pressure reducer and filter to the outdoor tap in that order.
- 2.Connect 13mm supply tubing; run it to the start of the bed.
- 3.Lay drip line along rows, weaving between plants; secure with U-pins every 50cm.
- 4.Cap the far end of each drip line with a blanking plug.
- 5.Turn on the tap and check every emitter — adjust spacing if needed.
- 6.Set the timer for 45 minutes daily at 6am during growing season.
In autumn, disconnect the system, flush it with clean water, drain it fully and store indoors — frost will split any water-filled tubing.