Tree fertilisation during heat stress
Quick answer
Do not feed a tree that is under heat stress. Its priority is water balance, not growth, and a fertiliser application raises salt concentration around the roots exactly when uptake is most difficult. The dates are published in advance, so preparation belongs in the months before the heat — not during it.
Why heat changes the calculation
- Water demand rises when salt concentration around roots is most dangerous.
- Transformation is faster. FAO notes all common nitrogen fertilizers act relatively quickly because of the high transformation capacity of these warm soils.
- Ammonia loss increases from surface-applied urea on alkaline soil.
- An irrigation failure is less survivable. A two-day fault at 45°C may not be recoverable.
- Foliar spraying is riskier — FAO requires dilute solutions to avoid osmotic damage to leaf cells, and heat compounds that.
The published windows
| Period | Dates | Temperature |
|---|---|---|
| Summer begins | from 21 May | great increase in humidity and temperature |
| Dry Summer | 6 June – 19 July | 42–46°C |
| Wet Summer | 20 July – 4 November | 45–46°C |
| Highest recorded | 20 August 1998 | 51.3°C |
May is the month for installing shade and checking the irrigation network. Not July.
What to do instead during the heat
- Maintain irrigation continuity above everything else.
- Check emitters after every dust storm — peaks fall on 9–12 and 17–24 June and 1–7 and 9–17 July.
- Keep mulch in place and clear of the trunk.
- Postpone any planned feeding until conditions moderate.
- Distinguish heat-stress symptoms from nutrient symptoms before acting.
Common mistakes
- Feeding through peak heat on a fixed annual schedule.
- Applying fertiliser and then allowing an irrigation interruption.
- Foliar spraying in the hottest part of the day.
- Reading heat scorch as a nutrient deficiency and feeding in response.
- Inspecting the irrigation network in July instead of May.
Boundary
No feeding calendar for Kuwait is given here. A month-by-month schedule would need an institutional local source; PAAF was unreachable and KISR publishes no extension guidance. We state the climate, which is published and verifiable, and stop there.
Related glossary terms
Sources
- Kuwait Meteorological Department — Climate. met.gov.kw
- FAO — Fertilizer and Plant Nutrition Bulletin 16, Chapters 3, 4 and 7.
- FAO — Irrigation Water Management Training Manual No. 5.
All accessed 27 August 2026. Last reviewed: 27 August 2026.
Field observation