You do not need to water the lawn before or after an application of Talstar P and Archer IGR for fleas according to the product label. Just be sure you are using the correct amount of product per gallon of water/coverage area.
The label advised not to exceed one ounce per one gallon of water. Talstar P is long lasting and generally does not need to be applied more than once every few months. It can be be reapplied once every 7 days at the low rate of 0.25 oz. After your first application if you are still seeing a heavy infestation you can reapply another application.
Please refer to product label for correct instructions. If your mixing rate is not per label instructions it may become ineffective.
Talstar P is labeled for ticks, however we would recommend you use our Outdoor/Indoor Flea and Tick Kit for the issue that you are asking about. This kit would include everything that is needed to treat both indoors and outdoors for a ticks infestation.
Please see out Treatment Guide for more information on how to get rid of ticks.