Choose a calm, dry day to apply your Roundup when the temperature is between 12°C and 25°C.
Drift may damage plants that you don’t want to kill
If it should rain within 6 hours of application repeat treatment may be necessary
It is important to ensure that you spray the entire leaf, but try to avoid run off.
The best time to apply is when the leaves are green and growing, typically in the spring and summer.