While sakura (cherry) blossoms are what most people think of when they hear of Japanese Hanami (flower watching) there is also plum blossoming. The Japanese plum, called ume in Japan, starts blossoming before the sakura season and was originally more popular than sakura watching. Usually the first ume blossoms starts from around the middle of February to Mars, depending on the region. The ume blossoming is therefore seen as a first sign of spring.
Just like with sakura flowers there are a lot of different varieties, from pure white to dark purple. And it's not unusual for visitors to mistake ume blossoming for sakura.
Can you tell the ume and sakura blossoms apart? The rounder flower petals to the left is ume blossoms, while the sakura petals to the right are pointier with a small cut. Another easy way to tell them apart is by their smell, or rather lack of smell. While the ume blossoms have a very fragrant sweet smell, the sakura flowers are almost completely odorless.
Osaka castle framed by ume blossoms.
The Japanese ume, which was originally brought in from china, is actually closely related to the apricot. But compared to the western plum trees the fruits are hard and sour even when ripe and are therefore processed before consumption. The most famous ume made products are umeboshi and umeshu.
Umeboshi is plums pickled in coarse salt then slowly sun-dried, making them round and wrinkly in appearance. The resulting very sour and salty taste goes well with rice and is often included in bento lunch boxes or in onigiri (riceballs). Umeboshi flavoured snacks and sweets are also common in Japan.
Umeshu is an sweet alcoholic drink often translated to plum wine in English. It's made by letting green unripe plums soak in a mixture of sugar and Shochu, which is a traditional Japanese distilled alcoholic beverage. After letting the plums steep for at least 6 months the umeshu is done. Umeshu's sweet taste makes it popular with woman and people who otherwise dislike alcohol. In Japan it's common to make your own umeshu at home and all required ingredients and bins can be found in most supermarkets during season.