The withe-rod is a deciduous suckering bush from the Adirondack Mountains that produces black berries in the summer which can be consumed raw or cooked. The leaves can also be brewed into tea. Some native American tribes made withe-rod a regular part of their diets. It grows primarily in bogs and swamps.
I. Appearance and Characteristics
Viburnum cassinoides, commonly known as northern wild raisin, blue haw or swamp haw, is a deciduous shrub native to eastern North America in the viburnum family, Viburnaceae (also referred to as Adoxaceae). It is often synonymized with Viburnum nudum var. cassinoides.
Viburnum cassinoides most often grows as a dense multi-stemmed shrub with a rounded crown, typically to heights of 5-6 ft (1.5-1.8 m). Its leaves are simple, opposite, ovate to broadly lanceolate, about 2-4 in (2.5-10 cm) long and have lightly toothed margins. Moreover, its lateral leaf buds are brown and particularly narrow (technically lanceoloid), whereas its apical flower buds have an inflated base. Both bud types are covered by 2 scales and rest above V-shaped leaf scars that each encompass 3 vascular bundle scars.
The flowers of Viburnum cassinoides emerge from a dense cluster called a dichasial cyme composed of many trios of one terminal axis and two lateral axes, which may act as terminal axes themselves and develop their own lateral axes. Each axis is terminated by a bisexual flower adorned with 5 white petals, a single pistil and 5 stamens topped with yellow anthers. Additionally, the stamens are perfectly centered on the flower’s sepals, which are partially fused at the base.
Northern wild raisin’s flowers develop into fleshy spherical fruits, which are botanically described as drupes and not berries. They gradually change colour from green, to pink, to dark blue, and at maturity their flesh is edible raw or cooked.
II. How to Grow and Care
Sunlight
Withe-rod in cold environment loves to grow in full sun on slopes and edging rocks in its natural habitat. Varieties adaptable to warmer climates grow well in full sun to medium shade; long exposure to strong light should be avoided. They can be shaded by buildings or big trees. A certain amount of scattered light is needed in the flowering phase to ensure enhanced and continuous flowering in warmer climates, but overall, plants in this genus perform well receiving 5-6 hours of continuous sunlight in a day.
Temperature
The optimum growth temperature range is between 5 to 27 ℃. It has good cold resistance; some native North American species can tolerate temperatures below -25 ℃. Its growth is poor at temperatures above 29 ℃, so it cannot survive in tropical summers. Germination requires 20 consecutive days of seed exposure to 24 ℃.
Withe-rod needs occasional watering during hot and dry conditions. The average plant during its first 2 years of growth needs 1.2 to 1.5 cm water bi-weekly. Once established, it doesn’t need much watering.
Watering
Originating from wetland areas, withe-rod thrives in consistently moist soil conditions, mirroring its natural preference for a humid environment. This species exhibits moderate drought tolerance but flourishes with regular moisture. For optimal health, it requires watering once every 1-2 weeks. Cultivated primarily outdoors due to its affinity for high humidity levels, withe-rod is an adaptable deciduous plant that benefits from increased water availability during its active growth season.
Soil
Withe-rod likes fertile, soft, slightly acidic soil with good drainage. It likes moist soil but does not grow well in waterlogged soils. It can grow in moderately fertile, fully drained soils that keep minimum moisture, but cannot withstand poor soil. The optimum soil pH range is 5.5-6.6. It can tolerate acidic media and drought with good air circulation in the root zone, which is made possible by the addition of peat moss or coco coir to the media. The best potting soil would be to mix 1 part of fully decomposed organic matter into 2 parts of garden soil.
Fertilizing
For optimal growth, withe-rod thrives with fertilization using balanced nutrition fertilizers, especially during active growth in spring. Apply a high nitrogen fertilizer sparingly to promote foliage; too much can impair flowering. Fertilize withe-rod once in early spring and again in mid-summer, using the recommended rates on the product label. Ensure even distribution and water well after application to prevent root burn. Adjust applications based on plant performance and soil tests to prevent overfertilization. Seasonal changes influence withe-rod’s nutrient uptake, requiring less fertilizer in fall and winter when growth slows. Regular fertilization enhances withe-rod’s vigor, bloom, and berry production while maintaining soil health.
Planting Instructions
The best time for transplanting is in late spring or early summer. It is best to plant them all on the same day. Take care that roots aren’t exposed to direct light and are buried deep into the planting pit.
Before planting, you need to know the height of a fully mature plant for the variety that you are growing. Generally, the role of thumb is to divide the height of the plant by 2 to determine to space. For example, if the selected variety is predicted to grow 4 m tall at full maturity, space the plants 2 m apart. Dig a pit measuring 30 cm deep and 30 cm wide.
Pruning
Light pruning to remove dead or dried branches or injured parts of the plant can be done at any time of the year. Withe-rod doesn’t need severe pruning; how much depends on the type of variety and purpose of growing.
Pruning to shape and beautify can be done in the late winter or early spring. When growing for borders and hedges, cut only 1/3 of the branches if they are severely intermingled. In other cases, pruning can be initiated right after flowering but before the setting of fruit. To avoid frost damage, don’t prune during frost or severe cold.
Propagation
Withe-rod is a versatile ornamental shrub known for its glossy leaves and clusters of white to light pink flowers, followed by blue to black berries. To propagate, semi-hardwood cuttings should be obtained from a healthy parent plant during its active growth phase. These cuttings can easily root under high humidity with proper care. It’s important to maintain moisture without waterlogging and to use a rooting hormone for best results. Providing a well-draining soil mix will foster robust root development. With attention to the specific growing conditions withe-rod prefers, gardeners can effectively multiply their stock of this attractive plant.
III. Uses and Benefits
- Culinary uses
Viburnum cassinoides bears edible fruits that may be consumed raw or cooked and incorporated into various dishes (chiefly desserts). Many native American tribes such as the Abenaki and Algonquins made use of them. While a single fruit contains little flesh, its stony pit accounting for most of its volume, said flesh is said to be “sweet and well-flavoured”. The plant’s leaves also make for a pleasant tea substitute, and for this they are “steamed over boiling water, rolled between the fingers, allowed to stand overnight and then dried in an oven to be used as required.”