How many freezing nights do we need here for peach trees? I'm considering planting a few semi-dwarfs in the shade of tall cedars. Evidently nectarines can't survive here - is that true?
Lane County Oregon
Chilling refers to the number of hours below 45ºF that fruit buds need to break dormancy, set fruit and develop fruit. Most deciduous trees require from 200 to 2,000 chilling hours to break dormancy. Chill hours for peaches will vary depending on the variety, but temperatures in the Willamette Valley are cold enough during a normal winter to receive sufficient chilling for all types of deciduous fruit. However, peaches and nectarines are difficult to grow in Western Oregon due to our cold wet climate in the spring and susceptibility to insects and diseases. Nectarines bloom earlier than peaches which makes them even more susceptible to frost damage in the spring during bloom, and hence more challenging to grow. If you decide to grow peaches, I recommend selecting a variety that is resistant to peach leaf curl, one of the main diseases that impacts peach production in this region. The following peach or nectarine cultivars are offered by a variety of west coast nurseries as curl resistant: Autumn Rose, August Etter, Avalon, Avalon Pride, Charlotte, Early Charlotte, Early Crawford, Frost, Indian Free, Kreibich, Muir, Nanaimo, Oregon Curl Free, and Q-1-8. I recommend the 'Frost' peach variety, it is productive and has great tasting fruit. It was bred for this region, and has both a low chill and heat factor so it tolerates the mild Pacific Northwest climates. It is also leaf curl resistant (you still need to spray for peach leaf curl the first few years when the tree is young, but it outgrows it). For more information on growing peaches in Oregon, check out the following OSU Extension publications: https://catalog.extension.oregonstate.edu/ec819 and https://catalog.extension.oregonstate.edu/ec631.