Answer: Evergreens are usually best planted in early spring so they have a full growing season to become well rooted before the cold weather. (A better established root system helps prevent them drying out during the winter.) Deciduous shrubs can be planted in fall or spring. Try to plant at least eight weeks before the ground freezes. Take care to keep the soil evenly moist (not saturated, not dried out) until it freezes.
Evergreens as a rule are slow growers. For partial sun you might consider Pieris japonica and also yews. Your local professional nursery staff may have other suggestions based on a more detailed understanding of the growing conditions where you want to plant (sun for how long and at what time of day, soil type, soil moisture, if it is windy or not, space available for plant to grow and mature, etc) and your overall design goals.
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