New Growth Drying in Extreme Heat: Spray Less, Water More, Wait for Fall

Frank: 25 roses, deadhead to 5-leaflet. New growth starts, then leaves dry and fall. Water every other day. Sprayed for thrips/mites/aphids (Ortho systemic). No pests found. Using J&P Once fertilizer. Problem roses get 10 hrs sun; healthy ones 6–7. Less issue last year without Once; improved when weather cooled.

Heat Is the Culprit

10 hrs intense sun + 90°F+ = physiological shutdown. Tender new growth desiccates. Spraying anything in heat worsens it (phytotoxicity). Once fertilizer unlikely cause—slow-release.

Survival Tactics

1. Minimize spraying – only early dawn or late dusk.
2. Water deeply daily – soaker hose, not sprinkler.
3. Shade cloth (30%) for 10-hr-sun beds during heat waves.
4. Don't fertilize in extreme heat.
5. Accept summer dormancy – many roses pause. Fall flush returns with cooler temps.

Sun Exposure Lesson

6–7 hrs = ideal. 10 hrs = stress. If possible, relocate or provide afternoon shade.