After my ski trip in Yuzawa, I returned to Tokyo and visited 3 parks famous for Ume (plum) and early Sakura.
Hanegi Park (羽根木公園)
This park is in Setagaya. According to the website, there were more than 600 Ume trees (out of 650) in blossom in the week when I visited.
One of the 3 famous gardens in Japan. It is in Mito, Ibaraki Prefecture, about 75min by express train from Tokyo plus another 20min by local bus. It was huge and I only visited probably one-third of it where the Ume garden was. Though it was on a weekday, many locals were there to enjoy the Ume Matsuri (festival). Out of the 3000 Ume trees planted, over 1600 were blooming in the week that I visited (as per its website). Spent 3 hrs+ there, would definitely return in the future.
Apart from Ume, there were other flowers such as some early-blooming sakura species, which attracted huge crowds.
Side trip to Shonan
head to Shonan coastline in Kamakura on a sunny day. Had a relaxing Italian lunch there.