this area was Jap and monoculture of water pepper. Sprayed 3x. Another 24 gallons today. Sprayed in stages. Started in mid May- how long for spray to take prior to rain? I suppose if it dries on plant should be effective? May have timed today's spraying too close. 2.5-4hrs. About to get pounded by storm. Extremely happy w release of grasses this year. YNS also showing up since last spraying few weeks ago Any thoughts or answers on rain question appreciated.