Of course, you have to meet just one of these weeping plum (shidare ume) trees to decide that the plums sweep you off your feet. This one’s not actually in my schoolyard but just outside it on the street.
If you want to know more, you must visit World kigo database. From the same resource:
“Next to the Cherry blossom, the plum blossoms are loved by Japanese poets and where enjoyed even more than the cherry in the Heian peroid. Sugawara Michizane was especially known for his love of the plum blossoms shared in many Tanka poems. More about him below.
Ume, Prunus mume, is biologically of the apricot family.
Other kigo with the plum
white plum blossom, hakubai 白梅
red plum blossom, koobai 紅梅
wild plum, yabai 野梅
plum with hanging branches, shidare ume 枝垂れ梅
old plum tree, roobai 老梅
plum plantage, plum park, bairin 梅林
Talking about a white plum blossom the reader will still feel the cold of winter, while a red blossom implies the warmth of spring. The smell of the plum (ume ga ka 梅が香) brings fond memories and an old plum tree refers to old age and loneliness. Just one flower on a tree ume ichirin (梅一輪）or one all white flower （umemasshiro, 梅真っ白）well that seems like a fair maiden. The plum-viewing (ume-mi, kan-bai 梅見、観梅) is more of an individualistic endeavor, different from the noisy, crowded cherry blossom parties.”