The abkhazi garden was actually someone's garden in the 1940's and has been maintained ever since, see www.conservancy.bc.ca/content.asp?sectionack=abkhazi for more information and visit it if you can, it's well worth it ^^
During our Berlin trip we went to the Berlin botanical gardens ( www.bgbm.org/bgbm/default_e.htm )... we should have reserved two days for that instead of one O.o
Located in Queen Elizabeth park, the Bloedel conservatory houses tropical and subtropical plants, as well as several birds. It is a small botanical garden, but certainly nice to have seen.
We took a trip from London to Kew to visit Kew Gardens in 2012. It's a wonderful place and you should go visit if you have the chance.
My parents have a lovely garden. When the weather's nice, it's usually a matter of just taking a camera, and walking around in it looking for something to photograph.
One of our natural stops in Portland was the Japanese Garden. The chibibis and Muk muk were very happy to be out in nature again!
The Berkeley Rose Garden is a love little amphitheater of fragrances that is in bloom from spring to late summer, peaking in May. If you're in Berkeley for a day: it's free! Go visit it an enjoy it for a few - unless it's been overrun by horse tails...
Part of our trip to Chicago involved exploring the Chicago Botanical Garden. Worth a visit, even in winter!
If you're visiting Dublin, and you like botanical gardens, you should probably visit the National Botanic Gardens of Ireland in Glasnevin.