Deutzias are members of the hydrangea family, producing small flowers in large clusters. They differ from hydrangeas in that the petals of deutzia flowers are anything from elongated and cascading to open and with a shape like a bell. They make excellent border plants, as well as hedges, and require virtually no maintenance. They are happy in full sun to part shade and can be pruned after flowering. Most deutzias are deciduous, but there are a few subtropical ones that are evergreen.
There are some 60 species of deutzia, but categorizing the difference between them has been challenging even for experts. For those in the Chicago area, it is worth noting that The Chicago Botanic Garden's collection includes 20 varieties and more than 300 plants. The Chicago Botanic Garden is in zone 6a, but the hardiness of this plant is far more extensive, as I will note below.
There are many different types of deutzias. Why choose them? Like forsythia and lilacs, they only bloom once in the spring, but extravagantly, and are a pleasant change from the typical spring-blooming plants. You probably won't see them in your neighbors' yards, giving you something a little different, but equally easy to grow and maintain. Smaller varieties can be grown as groundcover plants or placed in containers. All should be cut back after spring bloom. The genus was named after Johann van der Deutz, who is alternately described as a lawyer, botanist and scientist, who during his short life of 41 years sponsored plant explorations. Quite a guy!
In terms of personal experience, I have grown the plants I mention in zones 5a and 6b. I have grown them in high pH soil (which is acidic) and nearly neutral soil.
Also referred to as slender deutzia, this is a rounded shrub that grows anywhere from 2 to 4 feet, although it has been known to reach 6 feet. It has slender, almost delicate-looking arching stems. In spring, tiny white flowers, reaching as much as three-quarters of an inch, appear. The bloom sequence is less than three weeks, but it is breathtaking. The leaves are deep green.
It is hardy in zones 5 to 8. While best flowering is in full sun, also growing well in part shade. It makes a fine hedge. It also tolerates clay soil.
Deutzia scabra 'Codsall Pink'
This deciduous shrub is much like the above, but the flowers are fully double, and as the name indicates, pink. It is quite spectacular, and I personally own three. It blooms spectacularly, quite early in the season, and it has a very different impact from the more familiar shrubs, like witch hazel, that bloom at the same time. It is quite drought tolerant in shade once it is established.
'Codsall Pink' typically grows 6-10' tall with a spread of 4-8'. Fully double pink flowers. Synonymous with and sometimes sold as D. s. 'Godsall' or 'Godsall Pink'.
Deutzia scabra 'Pride of Rochester'
There is a bit of confusion online with this plant. Some sites indicate that Pride of Rochester is a white version of Codsall Pink. Others refer to it as Pride of Rochester 'Nikko'. Nikko is a completely different, and much smaller plant that I will cover below.
This shrub is very similar to Codsall Pink, except that the flowers are pure white, covering the plant in May. Hardy in zones 5-9, and with an average height of 6-8 feet, it is, like 'Codsall Pink' quite drought tolerant when established, and can bloom in dense shade, and handles full sun in the north. It is upright and treelike It grows quickly, and stays in bloom for several weeks. Because it does bloom quickly, it can be cut back hard to rejuvenate it. It is so tough that it has been successfully grown in hard clay and with very little water.
I was surprised to read that this shrub is rare and difficult to find. The sources for it are often found in gardens of home constructed in the 1880s, but the plant is not carried in garden centers. It is also rare in new developments. The few providers tend to try to propagate it. I was very surprised to read this, because I very much wanted this shrub, and had to do a great job of hunting to find one.
Deutzia x hybrida 'Mont Rose'
This particular deutzia appears to be popular in the U.K., as indicated in hits availability on several sites as well as gardening sites. Hardy in zones 5 a to 8b, it has lovely star-shaped double pink and white flowers. It grows to the standard 6 to 8 feet high and wide. It is quite elegant, and while it may be harder to find, it appears to me to be worth seeking out.
Deutzia x hybrida 'Magicien'
This deutzia is a little different from a standard deutzia in that it is said to have an interesting fall color. With a height and width of 4 to 6 feet, and hardy in zones 5 to 8, the gives it little something extra. The flowers are pink with white edging, and it is generally recommended as a hedge. With a bloom time in May, and workable in full sun to part shade, this would be a nice deutzia for someone who wants fall color. It is a pleasing shade of red.
Deutzia 'Chardonnay Pearls'
There is a new generation of deutzias that are enjoying great popularity and are very effective small shrubs. I received a deutzia 'Chardonnay Pearls' from Raulston Arboretum in 2004, and that plant has moved with me to my new home. It is extraordinary and bloomed spectacularly on the north side of my house in a part sun/part shade location, and then was moved to full sun on the south side of my new yard at the feet of a PJM rhododendron. I could not recommend it more highly. This trademarked and patented plant from Proven Winners possesses beautiful lime green foliage that lasts all season. But before that, it erupts into a large number of white flowers that emerge from tiny white buds, which completely cover the plant. Because of its short stature, it is very effective at the front of a shrub border.
Deutzia crenata 'Yuki Snowflake'