Weston Nurseries Garden Guidelines
All azaleas are technically “rhododendrons” but not all rhododendrons are azaleas; Weston Nurseries’ online Plant Library lists “Azalea” as the common name, with “Rhododendron” as the botanical genus. To readily distinguish between rhododendrons and azaleas in bloom, simply count their stamens. Azalea flowers have five stamens, or one per flower-lobe, while rhododendron flowers have 10 (or more) stamens, or two per lobe. Azaleas also tend to have tubular or funnel-shaped flowers, while rhododendron blooms are generally more bell-shaped. See our “Rhododendron Garden Guidelines” information document for more detailed information.
Azaleas are classified as either evergreen or deciduous. In general, evergreen azaleas have a mounding growth habit while deciduous types tend to grow more upright. When planted in a proper location with rich soil, all azaleas will thrive for decades with minimal care.
Evergreen azaleas, with their explosion of colorful spring blossoms, are a welcome sight when winter releases us from its frosty grip; they typically retain a portion of their foliage over the winter, opening their blooms starting in mid-May in Hopkinton.
Deciduous azalea cultivars can bring appealing scents to your property, as well as season-extending blooms. Many deciduous hybrids and cultivars begin flowering before summer begins, carrying their foliage beauty into the fall, before dropping their leaves for winter. The so-called “summer azaleas” are deciduous azaleas that bloom in Hopkinton from mid-June and through much of July, depending upon the cultivar.
All azaleas prefer acidic soil, high in organic content that drains well and is properly prepared. Since they are shallow rooted, it is easy for them to dry out and, at the same time, drown if over-watered. Sandy or dry soil should be amended before planting as should heavy clay; add peat moss, peat humus or compost to remedy the problem. Some native azaleas and cultivars, including Azalea viscosum, will tolerate damp soil conditions. Mulching will help retain moisture, discourage weeds, and cool the soil.
Evergreen azaleas prefer partial shade where they are protected from wind and harsh summer and winter sun. Planting them in a protected eastern or northern exposure is preferable to western or southern. However, a southern exposure can work if it is shaded, the soil is rich, and the plant is protected from wind. Many will tolerate deep shade, although they may become leggy and not flower as heavily. Deciduous azaleas prefer full sun but will tolerate light shade. If planted in shade, they will become open branched, flower less profusely, and be less vigorous. Azalea arborescens, Azalea viscosum, and Azalea vaseyi and their cultivars can tolerate more shade than others.
Azaleas generally need minimal supplemental feeding. A balanced fertilizer for acid-loving plants, such as Holly-Tone can be applied conservatively each spring.
Spent flowers can be removed to promote new growth but is rarely necessary. Evergreen azaleas rarely require pruning, but if necessary should be pruned right after flowering. Deciduous azaleas require pruning only if the plants become leggy and should be done right after flowering.
In challenging locations, evergreen azaleas may benefit from winter protection. If the site receives full sun and or the site is windy, an application of an anti-desiccant spray such as Wilt-Pruf can help prevent the plant from drying out. Providing additional water in the fall, if the season is dry, will also help. In our climate, evergreen azaleas are often considered semi-evergreen and may lose a major proportion of their leaves over winter. They may look a bit scruffy in the spring, but will recover quickly. Often, an azalea that has lost most or all of its leaves after a harsh winter will leaf out and perform admirably. In some cases, the plant will flower heavily, but have no foliage until new growth is pushed out. Weston Nurseries has developed and introduced some azaleas for improved performance in Zone 5 gardens, including ‘Bixby’, ‘Pink Clusters’ and ‘Majesty’.
Our designers have decades of experience!
Design consultations start at only $300!
Over 100 years of excellence in providing top-quality plants!
Copyright © 2025 Weston Nurseries. All rights reserved.
93 East Main Street
Hopkinton, MA 01748
(508) 435-3414
Daily 9am to 5pm
By The Yard
Mon – Fri 7am to 3pm
160 Pine Hill Road
Chelmsford, MA 01824
(978) 349-0055
Mon – Fri 8am to 5pm
Sat – Sun 9am to 5pm
1099 Main Street
Hingham, MA 02043
(781) 749-3773
Daily 9am to 5pm
339 South Great Road
Lincoln, MA 01773
(781) 259-8884
Daily 9am to 5pm
