Q.The deer were eating the leaves off of my ornamental cherry tree. I accidentally sprayed the affected area with weed killer inste
ad of deer repellant. What should I do to the affected area? The leaves where I accidentally sprayed are wilting and turning brown. I sprayed approximately 36 hours ago. Once I detected my mistake, I have sprayed the affected areas with water to try to wash of the weed killer. Do you have any suggestions on what I can do overcome this spraying error

I'm afraid there is not much you can do at this point except 'wait and see'. If you used a systemic herbicide like RoundUp you may have killed the tree and root system. If it was a foliar desiccant like diquat or herbicidal soap it may re-foliate in time.
It's a tragic situation, but not uncommon. Yours is the second question like this that I've answered this week. It's a good lesson to always use separate sprayers for herbicides, and mark them well for identification of the contents.