Stone Fruit
Stone fruit are very susceptible to damage from the fungus and bacterial diseases that are prevalent in the cool humid climate conditions of the Puget Sound region. Also the lower seasonal heat levels, compared with regions such as eastern Washington or California, may not produce the high quality and flavor of the common commercial varieties. Some pollination problems occur when bad weather at bloom time limits bee activity, especially for early bloomers like apricots and early plums.
Beginning in the early 1970s, Dr. Bob Norton started the stone fruit evaluation trials for the purpose of finding the stone fruit varieties that would produce a reliable crop of good quality fruit. These trials continue to test new introductions, in search of improved varieties for our area.
Peach & Nectarine Variety Trials
Productivity and disease susceptibility are the two major limiting factors in variety selection for peaches and nectarines in western Washington. Many varieties that do well in warmer areas are unproductive in the cooler marine climate of the Puget Sound region. So far in trials at Mount Vernon we have eliminated a number of poorly performing varieties. Some reliable producers have fruit that is not top quality. Showing good promise are several introductions from the Harrow, Ontario fruit breeding program, and some other new introductions from New Jersey, Michigan, and Georgia.
Peach leaf curl, bacterial canker, brown rot and coryneum blight all attack peach and nectarine trees, so they are not good candidates for a no-spray orchard regime. Nectarines in particular can be subject to fruit cracking, which damages the fruit even if the cracks remain dry and do not develop rot.
For a summary of peach and nectarine variety trial results, see Harvest Report 2003: Tree Fruit.
Peach cultivars and selections currently planted in 2007.
Nectarine cultivars and selections currently planted in 2007.
Peach bloom data: Current Archive
Nectarine bloom data: Current Archive
Plum Variety Trials
European, Asian and hybrid plums can all be grown successfully in our area. European plums (Prunus domestica) are generally the easiest to grow, and a wide range of these firm-fleshed, freestone types are available for home gardeners. Plum trees are usually vigorous and productive, less prone to disease and nutrition problems than other stone fruit kinds, and can be used not only for fresh eating but also for canning, drying, fruit leathers, and other culinary uses.
Japanese plums (P. salicina) and hybrid types (P. institia) can also do well, but variety selection is very important since certain varieties perform well and others are disappointing. Fruit is usually cling stone and more juicy than the European types. They are excellent for fresh eating and some can be used for flavorful jelly. Canning and drying are not recommended. Damson types and the small, round "bush" plums are often quite tart for fresh eating. However, they are very productive, supplying plenty of fruit for jelly, jam, and even wine.
For a summary of plum variety trial results, see Harvest Report 2003: Tree Fruit.
Plum cultivars and selections currently planted in 2007.
Plum bloom data: Current Archive
Cherry Variety Trials
The main cherry problems are fruit cracking, bacterial canker, and damage to the crop by birds. The introduction of dwarfing rootstocks such as Gisela 5 makes it possible for home growers and orchardists to grow small, manageable trees that can be netted for bird protection. Adding a rain cover to the bird net is a possibility. Select varieties that have less genetic tendency to crack – usually those with somewhat softer flesh. Also, later ripening varieties (late July) may take advantage of the better weather and late market opportunities.
Bacterial canker often attacks sweet cherry trees in this area, and over time it is probably the most serious threat. Sour (pie) cherries such as Montmorency are usually much less susceptible to canker, show little damage from rain, and because they are often later blooming, the weather conditions at bloom time make good pollination more likely.
For a summary of cherry variety trial results, see Harvest Report 2003: Tree Fruit.
Cherry cultivars and selections currently planted in 2007.
Cherry bloom data: Current Archive
Cultural Trial – Gisela Cherry Rootstock
Progress report on the Gisela rootstock trial: Current Archives
Apricot Variety Trials
Apricots are the most problematical of the stone fruits to grow in western Washington. They bloom early, often in February or March when cold weather prevents effective pollination or frost damages the flowers and young fruit. They are also susceptible to serious diseases such as bacterial canker, pseudomonas, and brown rot. Some varieties do not get as much heat as they need for proper maturity in our cool maritime climate. Here again research continues to seek out disease resistant, productive varieties that are better adapted to local conditions, but the goal of a truly well adapted apricot variety is still some way off. In the meantime, tricks such as the under-roof trellis mentioned for peaches, and a diligent disease control program, can help to give better results.
For a summary of apricot variety trial results, see Harvest Report 2003: Tree Fruit.
Apricot cultivars and selections currently planted in 2007.
Apricot bloom data: Current Archive