Depends on the type of sprayer you are using. The heads on the small hand carried pressurized sprayers used to apply most garden chemicals rotates 180 degrees. Then all you have to do is hold the wand low on the plant and it mist sprays up under the leaves.

Wearing gloves and the proper clothing as listed on the label also helps avoid skin contact.

Dave

Ha...I knew there had to be something I was missing! I'll check out our sprayer and kick myself for not figuring that out sooner. I was crouched down this morning trying to spray up and thinking there had to be a better way!

Thank you, thank you, thank you. I'm learning something new!

Really quite simple. Make sure the plastic (?) tube attached to the adjustable head if full of water. The water help keep the tubing from colapsing when heated. Now, use a small butane torch to GENTLY heat the tubing until it begins to bend. Slowly ben it until you’ve gone past 90 degrees. Stop heating and let it cool back to firm again. You now have a wand that, when you are standing, will spray undersides of leaves with the spray shooting slightly AWAY from you. A separate $10 sprayer can be kept exclusively for this task.