Yarrow, Achillea millefolium, grows in sunny areas and it likes sandy soil. I have lots in my backyard and it spreads somewhat fast and is very hardy. I get flowers around the end of June with more consistent hot weather. It seems to survive drought quite well as we get almost no rain for 8 weeks in July and August. It also has very wispy, ferny leaves and even the leaves look nice.
Another commenter mentions:
I drop a few drops of eucalyptus oil in coconut oil and rub it on exposed skin. It works really well.
The study about how DEET is toxic.
Making the tincture.