Unfortunately all the cities around Tokyo that I haven’t visited are all two hour trips with regional trains. So that either means getting up early or go somewhere else. And there are many temples and gardens which I haven’t visited yet. One of them is Sankeien in Yokohama.
Sankeien is one of Yokohamas main attractions yet it is a bit off the other sights (Minato Mirai, China Town). Plus you have to take the bus to reach Sankeien. Once reached, the way is clearly signed out. If I didn’t have trouble finding the place, you won’t either.
Anyway, it’s quite a big garden with a wide variety of flowers meaning that there is something special to see every month. They have a flower timetable and an event guide. I don’t know if both are available in English since I took the Japanese ones.