Our friends "across the pond" in Great Britain have always had green thumbs, love to garden, and have spectacular public gardens. Here a just two:
Royal Botanic Gardens, Kew in Richmond outside of London: The garden was formally started in 1759 by the parents of George III around Kew Palace, a royal summer residence. The garden’s famous Victorian glass houses were built in the early 19th century. Its 300+ acres are continually evolving and changing.
There is easy access to Kew Gardens from central London by rail to the Kew Bridge Rail Station then an easy 10 minute walk to Elizabeth Gate. There are also several bus routes or you can travel by Tube to Victoria Gate and enter the gardens from there. When I visited I took a boat up theThames to the garden - a lovely ride with views of the city along the way. and then a picnic lunch in the gardens.
There is a lot to see so visit their web site for a virtual visit to the garden's highlights:
A quick view of the gardens can be found on this site: https://whc.unesco.org/en/list/1084/video/
Royal Horticultural Society’s garden at Wisley in Surrey, England is another garden noted for its beds of seasonal flowers: https://www.youtube.com/watch?v=X2WealAPZHU
You can go further on your garden tour - other parts of Europe also have beautiful, unique gardens.