Niagara Parks plants over 100,000 tulips along the Parkway each year. Peak bloom is usually the first two weeks of May, depending on temperatures. The display from Queen Victoria Park to the Floral Showhouse is one of the prettiest urban gardens in Canada.
High Park in Toronto has the cherry blossoms — about 10 days at the end of April. Tours can route through on the way out of the city if timing aligns.
Wineries in May are quiet, polite, and pouring their new releases. Tasting fees are usually waived with a bottle purchase, and the patios are open without a reservation. If you have flexibility on travel dates, May is the underrated month.