People and pets should be out of the area while applying Celsius WG Herbicide until it has a chance to dry completely. This normally takes 4-6 hours depending on weather. While it is not an insecticide to kill insects, they could be injured if sprayed directly. It would be best to apply when they are not in the area, early morning or later in the evening.
Celsius Herbicide should not cause fungus in your lawn when used as directed on the product label. For more information, we would recommend contacting the manufacturer (Bayer) directly at 800-331-2867.
Pets can return to an area that has been treated with Celsius WG as soon as everything is dry (usually a couple of hours).
In general the Celsius WG Herbicide is safe for people and pets so long as you keep them out of the area while applying the chemical, and until the product has had plenty of time to dry (normally a few hours). If your cat has any sensitivities we would recommend consulting your vet, otherwise the cat should be safe to eat the grass as long as its dry.
As long as the temperature during the application of the Celsius WG Herbicide is not 85 degrees or above, then it does not matter what temperature it reaches mid day. The best time to apply herbicides is either early morning when dew is still fresh on the ground or late afternoon when the lawn and weeds are under less stress from the environment. Temperatures over 85 degrees will cause extra stress on your desirable turf, possibly causing damage.
Celsius WG Herbicide is a post-emergent so therefore it would not effect the seeds, it would only effect germinated seeds. If you are looking for a pre-emergent. You can consider Pendelum 2G Herbicide and verify with your local extension office for optimal timing for prevention on buttonweed in your area.
The best time to use Celsius WG Herbicide or any other herbicide will depend on where you are treating and the specific type(s) of weeds you need to treat. Most post-emergent herbicides will be most effective when the target weeds are young actively growing. If you need help with identification or determining the best time to apply, you can call your local cooperative extension office and ask to speak to the master gardener on staff and he/she should be able to help you.
