Catnip tincture. On the repellency scale DEET is +10 (and toxic), catnip is +49-50 on a scale of 100 according to Iowa State U research. Actually the scale goes from minus 100 (attractant) to positive 100 (repellant). You can spray on the tincture made out of 190 proof ethanol from flowering tops of the fresh plant. It evaporates quickly though so reapply hourly if done this way. I have catnip growing here (it’s easy to grow) and was planning on making some tincture of the flowers this year if they come back. You can buy catnip oil too or make an infusion of the flowers in oil, like olive oil.
Yarrow flower tincture and oil is 2nd best. The US Army study using whole plant tincture showed it more effective than DEET. A native plant and easy to grow.
Mugwort, 3rd, all Artemesias, dry or fresh plant tinctures …also easy to grow.
Rose Geranium oil, high in geraniol esp good to repel ticks, lavender too but not as powerful
All are safe for dogs, tinctures are for cats…oils may or may not be safe for cats.
From the Home Medicine Summit October 2018, Julie James, Green Wisdom Herbal Studies.com