Diff: Herbicide Injury

== Herbicide Injury ==

== Herbicide Injury ==

Herbicide injury is one of the most important [[Rose Rosette Disease]] look-alikes. It can distort new growth, narrow leaves, stunt shoots, and make clusters that alarm growers.

Herbicide injury is one of the most important [[Rose Rosette Disease]] look-alikes. It can distort new growth, narrow leaves, stunt shoots, and make clusters that alarm growers.

=== Signs ===

=== Signs ===

* Narrow, strap-like, twisted, or pale new leaves.

* Narrow, strap-like, twisted, or pale new leaves.

* Stunted clusters that may look like small witches brooms.

* Stunted clusters that may look like small witches brooms.

* Symptoms following weedkiller use nearby, contaminated tools, drift, vapour movement, or treated mulch/compost.

* Symptoms following weedkiller use nearby, contaminated tools, drift, vapour movement, or treated mulch/compost.

* Damage may appear on the side facing a drift source or after a known spray event.

* Damage may appear on the side facing a drift source or after a known spray event.

=== Why it confuses RRD ===

=== Why it confuses RRD ===

RRD and herbicide injury can both produce distorted clusters. RRD is more concerning when one cane continues to produce progressively abnormal growth with unusual soft thorniness, bud failure, and decline. Herbicide injury often fits a timing or exposure pattern and may improve as clean new growth appears.

RRD and herbicide injury can both produce distorted clusters. RRD is more concerning when one cane continues to produce progressively abnormal growth with unusual soft thorniness, bud failure, and decline. Herbicide injury often fits a timing or exposure pattern and may improve as clean new growth appears.

=== What to do ===

=== What to do ===

* Stop all possible exposure first.

* Stop all possible exposure first.

* Take whole-plant photos and note the dates of nearby herbicide use.

* Take whole-plant photos and note the dates of nearby herbicide use.

* Water and care normally. Do not overfertilise a stressed plant.

* Water and care normally. Do not overfertilise a stressed plant.

* Wait for clean new growth when the plant is stable, unless symptoms strongly suggest RRD or the plant is declining.

* Wait for clean new growth when the plant is stable, unless symptoms strongly suggest RRD or the plant is declining.

* Prune out dead or badly damaged growth after the extent of injury is clear.

* Prune out dead or badly damaged growth after the extent of injury is clear.

=== Prevention ===

=== Prevention ===

* Do not spray herbicides near roses on windy or hot volatile conditions.

* Do not spray herbicides near roses on windy or hot volatile conditions.

* Shield roses and avoid treating weeds under canes.

* Shield roses and avoid treating weeds under canes.

* Keep sprayers and watering cans clearly separated.

* Keep sprayers and watering cans clearly separated.

* Avoid unknown mulch, compost, or manure where herbicide contamination is possible.

* Avoid unknown mulch, compost, or manure where herbicide contamination is possible.

=== Sources ===

=== Sources ===

* [RHS: Rose problems FAQ](https://www.rhs.org.uk/plants/roses/frequently-asked-questions)

* [RHS: Rose problems FAQ](https://www.rhs.org.uk/plants/roses/frequently-asked-questions)

* [UC IPM: Roses diseases and abiotic disorders](https://ipm.ucanr.edu/home-and-landscape/roses-diseases-and-abiotic-disorders/)

* [UC IPM: Roses diseases and abiotic disorders](https://ipm.ucanr.edu/home-and-landscape/roses-diseases-and-abiotic-disorders/)

* [University of Maryland Extension: Rose Rosette Disease](https://www.extension.umd.edu/resource/rose-rosette-disease)

* [University of Maryland Extension: Rose Rosette Disease](https://www.extension.umd.edu/resource/rose-rosette-disease)

* [UK HSE: Garden home pesticide guidance](https://www.hse.gov.uk/pesticides/using-pesticides/garden-home.htm)

* [UK HSE: Garden home pesticide guidance](https://www.hse.gov.uk/pesticides/using-pesticides/garden-home.htm)

[[Category:Care]]

[[Category:Care]]

[[Category:RRD]]

[[Category:RRD]]

[[Category:Identification]]

[[Category:Identification]]