You can use a pump start relay, which is pretty standard for controlling a pump in sprinkler system. You can search on Amazon and find plenty of options, such as this:
https://www.amazon.com/bomba-aspersor-%C3%B3rbita-arranque-sistema/dp/B000I19I5E
it’s usually rated by the horse power that it can handle. The horse power should be sufficient to match your pump.