As we head into the peak spring season and the temperatures continue to rise, more and more of our landscapes are popping with spring color. Another shrub all gardens should contain is a deciduous Azalea. Us gardeners have plenty of evergreen options to help with our Azalea and Rhododendron addictions, but a deciduous Azalea specimen offers a different look with brighter flower color options, fragrance on many cultivars, and of course, spectacular fall colors as they go dormant before winter.
Many gardeners refer to deciduous Azaleas as “Exbury” Azaleas, which is partially true. Exbury Azaleas are absolutely one type of deciduous Azalea, but there are a number of species, hybrids and varieties as well. Gardeners can find some 17 species that are native to North America alone. Exbury types and many of these species have been used in breeding for centuries and worthy selections have resulted, giving us many of the named cultivars we utilize today. Our PNW native is the Western Azalea (Rhododendron occidentale), which is lovely in the wild, fragrant, and has served as parentage for many other varieties. Other fun species to search out for our area include Rhododendron schlippenbachii, Rhododendron viscosum, Rhododendron mollis and Rhododendron luteum – all great growers in the PNW with fun spring flowers and excellent fall color.
Just like their Rhododendron and evergreen Azalea brethren, deciduous flavors of Azalea love our acidic soil, spring rains, and mild maritime climate. One important difference to keep in mind between deciduous Azaleas and typical Rhododendrons is that they like some mulch, but not as much – be careful to only lightly mulch and avoid burying up onto the crown of these plants. They are easy to cultivate in sun or part shade, in almost any garden setting. Feed them twice a year, once in March and again in June, with a good organic Rhododendron/Acid type fertilizer, which will provide for optimum growth and flower. I sprinkle a little Ultra Bloom from E.B. Stone under mine as well every June, maximizing the bud set for the next season. Remember a well fed plant will reward you with superior flower power, one that is struggling simply will not.
Deciduous Azaleas are old wood bloomers, meaning that they set their flower buds over the summer to open up the following spring. I always mention this for two reasons… First, prune them after bloom only – if you cut them back in summer/fall/winter you will be cutting off your flowers for the next year. Second, if you don’t feed them properly or you allow your plant to become drought stressed in summer months, they will abort bud production and offer an inferior flower show the following spring. Removing dead wood or tidying the structure over winter is perfectly fine, but absolutely avoid tipping or shearing back these plants. In my opinion, you should let these beauties mature naturally, using them in the background of the garden to provide height. Pruning sparingly will allowing them to achieve a nice open, natural look versus the sheared little meatball-looking plant.
Now, let’s get to the proverbial elephant in the room; powdery mildew. Most gardeners I talk to are worried about mildew on this type of Azalea, but honestly this can be kept to a minimum or avoided very easily. The more sun and air circulation it has, the less mildew it will have - simple as that, with all plants. Crowding these with other shrubs is not necessary, nor is planting them in deep shade. If we site them in a sunny garden, with at least half day sun, and give them proper room to grow, I highly doubt you will have to battle mildew regularly. I can only use myself as an example, and I have had stunning orange deciduous Azaleas (‘Arneson Gem’) in my front rockery garden for over 15 years in full sun and have never had one issue with mildew or anything of the like. If I had let the neighboring plants go crazy and bury it, perhaps I would be singing a different tune.
Now let’s talk some of the best flavors of deciduous Azalea, and some quick attributes of each. Remember to always check individual varieties for height, spread, bloom time, and fragrance.
Weston Azaleas: This group blooms much later, from June into early July. They are super fragrant and have honeysuckle-like flowers that are simply fabulous. Numerous colors are available like ‘Popsicle’, ‘Lemon Drop’, and ‘Innocence’.
Arneson Azaleas: This Oregon breeder produced some fabulous compact and mildew resistant options with great color. Seek out ones like ‘Arneson Gem’, ‘Arneson Ruby’ and ‘Arneson Golden Solitaire’. No fragrance, but colors are vivid and flowers are large.
Irene Koster: This specific Western Azalea hybrid is perfect with its pink to white flowers and pleasing fragrance every spring. We have one of these on our grounds here and it is a most worthwhile choice for the home gardener for sure.
Fragrant Star: This hybrid has nice bluish-green foliage and extremely fragrant pure white flowers, growing with a nice and compact shape. One of my favorites for sure - who says white has to be boring?
Gibraltar: I have been doing this for 30 years and every single year without exception this is the most popular choice with nursery patrons. Want a neon, true orange flower? Then this one is for you!
Klondyke: Still the standard for the brightest, pure, golden yellow flower anywhere. Another popular choice with nursery patrons, this flavor is sure to make you smile every spring with its darker new growth and bright flower color.
Lights Azaleas: This series comes to us from the University of Minnesota and Bailey Nursery’s First Editions Shrub Program. They are super hardy, compact, and heavy blooming. Lots of colors are available, but typically ones like ‘Electric Lights Double Pink’, ‘Electric Red’, ‘Tangerine Lights’, and ‘Mandarin Lights’ are around at the garden centers.
I am hoping you will consider a deciduous Azalea or two for your home landscape. They absolutely make wonderful specimens, and when planted properly will give you years of garden enjoyment. This is the perfect time of year to stop into your local garden center to see them in bloom and speak with a Certified Professional Horticulturist about the right choice for your garden setting. Remember, not everything has to be “evergreen” in the Evergreen State - some of the best plants are deciduous, which will add some fun autumn color into your landscape year after year.
