A disease called fire blight might pop up in some pear and apple trees beginning around May. It can be common several weeks after spring rains, particularly if trees were flowering. It can lead to tree death if not controlled when it’s first seen.
Search results for:
Delay pruning grapes as long as possible in the spring to reduce disease possibilities and avoid any late spring frost damage after pruning. Immediately after pruning grapes, consider applying a fungicide to the vines if there were problems with grape bunch diseases last year.
My experience with Mexican petunia is that it grows like a weed, and I consider it the broadleaf version of Bermuda grass, aka devil grass. If it’s contained in an area and prevented from spreading into the landscape, I think it will be OK.