Plant Type, Taxonomy for Virginia Sweetspire
Plant taxonomy classifies Virginia sweetspire (or "Virginia-willow") as Itea virginica. 'Henry's Garnet,' 'Little Henry' and 'Merlot' are popular cultivars. This article focuses on Itea virginica 'Merlot.'
Virginia sweetspire bushes are deciduous flowering shrubs.
Characteristics of the Shrub
'Merlot' Virginia sweetspire shrubs reach about 4 feet tall by 4 feet wide at maturity.
A late spring or early summer bloomer, this bush produces wispy racemes (the drooping "spires" referred to in the plant's common name) of small, white flowers on arching branches. The racemes are 3-6 inches long. The mildly fragrant flowers to have a "woodsy" smell, although most people call it "sweet." But these plants are valued more for their deep-red fall foliage than for either the appearance or the aroma of their blossoms.
Growing Zones, Sun and Soil Requirements
The shrub is native to eastern North America and can be grown in planting zones 5-9.
Grow Virginia sweetspire shrubs in full sun to partial shade and in a soil amended with compost. Their water needs as young plants are slightly above average. Superior flowering, compactness, and fall color will be achieved in full sun (that is, at least 6 hours of sunshine each day, on average). Although these bushes are considered plants tolerant of wet ground and of clayey soils, they will nonetheless perform best in well-drained soils.
Without a doubt, the best feature of Virginia sweetspire plants is the long-lasting burgundy color (sometimes with hints of orange or yellow) of their autumn leaves, as the cultivar name 'Merlot' suggests. One certainly would not grow these bushes for their blossoms alone, although the fact that they do bear numerous flower heads that offer a fairly nice smell is a welcome bonus.
But the fall color is good enough to qualify this bush as one of the best landscaping plants of which beginners are unaware, generally.
Uses in Landscaping
This shrub forms a dense mass of leaves if grown in full sun, making the bushes effective in shrub borders or foundation plantings. An understory plant in the wild that naturalizes easily in the landscape, this shrub can also be used in woodland gardens. But, with excessive shade, you will sacrifice some fall color, etc. The plant's tolerance of wet soil makes it suited for use around water features.
While its root-suckering can be a nuisance, this very attribute qualifies it as an excellent plant for erosion control. It will also help you gain a bigger display, since this quality allows the plants to spread. This can be considered a good thing, since they look better displayed in a mass planting, rather than individually.
Water Virginia sweetspire shrubs well when young, to get them established. Once mature, they are reasonably drought-tolerant shrubs. Stay ahead of any root-suckering that may occur if you do not wish for your bushes to spread. Root suckering will be worst (or best, depending on what you want) in wet ground.
Prune to remove any dead wood you find in spring on your plants. In USDA growing zone 5, a bush will likely experience several inches of winter die-back on the tops of the branches (they turn a tan color). This is unfortunate, since the bush blooms on old wood. So such die-back in winter means the loss of some of the flower buds that would turn into blooms in spring.