I would like to know how well the following trees will do in the Seattle area ?
(1)Prunus mume var. ‘Matsubara Red’
(2)Prunus ‘Kiku-shidare-zakura’
Both species you mention should do well in the Seattle area. Prunus ‘Kiku-shidare-zakura’ is described in Arthur Lee Jacobson’s Trees of Seattle (2006). Its other common name is ‘Cheal’s Weeping Cherry.’ The Japanese name means “weeping chrysanthemum cherry.” Its form is arching and weeping from the point where it has been top-grafted. According to Jacobson, the tree tends to be gawky and a bit sparse, but the flowers are very double. It is common in Seattle.
Prunus mume is also listed in Jacobson’s book. This tree and its cultivars (such as ‘Matsubara Red’) are less common in Seattle. You might be able to see examples in the Seattle Japanese Garden, the Kubota Garden, or Seattle Chinese Garden.
Because the common name of Prunus mume is Japanese apricot, there is sometimes confusion between Japanese flowering cherries and apricots. Prunus mume does produce fruit, but they are small and “bland to somewhat bitter,” and in Japanese cuisine they are preserved in salt and used as a condiment (Umeboshi plum). The more familiar fruiting apricot tree is actually Prunus armeniaca (and its cultivars).