When to plant plum trees in Newport and Lincoln City, OR

European or Japanese plums

European plums, including Italian prune and Stanley, bloom later and fruit on their own, which makes them the easiest choice for most Northwest gardens. Their dense, sweet flesh is great fresh, dried or baked. Japanese plums such as Shiro and Methley bloom earlier, have juicier fruit and ripen in mid-summer. Shiro sets a much better crop with another Japanese plum nearby, and Methley is a popular partner because it's partly self-fertile. In frost-prone spots, the earlier bloom of Japanese plums can get caught by a cold snap.

Why plums are pruned in summer

Plums and other stone fruits are prone to silver leaf and bacterial canker, which enter through pruning cuts in cool, wet weather. Cuts made in dry summer weather heal fast and stay clean. Prune lightly after harvest or in July, removing dead wood, crossing branches and tall upright shoots.

Heavy crops are common. Thin young fruit to 3 to 4 inches apart in early summer: the remaining plums grow bigger, brown rot spreads less between touching fruit, and branches are less likely to snap.

Harvest and brown rot

Brown rot is the main Northwest plum problem. It blights blossoms in rainy springs and turns ripening fruit into fuzzy gray balls that dry into mummies. Those mummies carry the fungus into next year, so pick them off the tree and the ground. Good airflow and thinning help a lot.

Italian prunes are sweetest when left to hang until they wrinkle slightly at the stem. Japanese plums soften quickly once ripe, so check every couple of days.