Swamp dewberry (Rubus hispidus) is a perennial woody vine with trailing stems found in woodlands, meadows and fields. Swamp dewberry blooms white flowers from spring to summer and attracts bees, flies and butterflies. The fruits it produces are similar to black berries but have a sour taste. Birds, turtles, mice and squirrels feed on the berries. It grows in full sun to partial shade.
I. Appearance and Characteristics
Rubus hispidus, with the common names swamp dewberry, bristly dewberry, bristly groundberry, groundberry, hispid swamp blackberry or running swamp blackberry, is North American species of dewberry in the rose family.
The plant grows in moist or sometimes dry soils, ditches, swales or open woods in central and eastern North America, from Ontario and Minnesota east to Newfoundland, and south to South Carolina and Mississippi.
Rubus hispidus is a small, herb-like shrub up to 20 cm (8 inches) tall. The twigs are red and have bristles. Flowers are generally in small clumps, each with five white rounded petals. The fruit are dark purple, almost black.
II. How to Grow and Care
Sunlight
Swamp dewberry thrives optimally in partial sun conditions, which involve a balance of sunlight and shade throughout the day. While it can tolerate full sun exposure, such intense light may lead to stress and potential damage if not accompanied by sufficient moisture. Swamp dewberry’s ability to adapt to different light levels can be observed through its foliage, with leaves possibly exhibiting changes to protect against excessive light. When planting outdoors, swamp dewberry fares best in areas that mimic its natural habitat, offering dappled light. Indoor cultivation is not typical for this species, as its natural environment is outside.
Temperature
As a large genus, Rubus has a wide distribution range which means you are always likely to find a proper species or cultivar that grows well in your garden. Generally, Rubus species flourish in temperate zones, and adaptable to slightly harsh conditions. Select cultivars that may thrive in your garden, thus the preferable climate will encourage them to bear more edible fruits. Swamp dewberry prefers moist to slightly dry conditions, so it is important to avoid waterlogging.
Watering
Adapted to its native marshy environments, swamp dewberry thrives in conditions where moisture is abundant. This species exhibits a high tolerance for wet soil and prefers consistent humidity, making it well-suited to boggy areas. Watering should be moderated to once every three weeks, aligning with its natural adaptation to sustained periods of wetness followed by drier intervals. As an outdoor plant commonly found in damp woodlands, swamp dewberry benefits from mulching which helps retain soil moisture and mimics the leaf litter of its habitat.
Soil
Swamp dewberry is not picky about soil, as long as the soil is slightly acidic and well-drained. The ideal soil pH range for it is 5.5–7 while a few species and cultivars of Rubus may tolerate slightly alkaline soil as well. Rich loamy soil mixing with some sandy soil can be a good option. Always remember to avoid the heavy clay soil because it can become soggy easily. Hilled soils that promote drainage can also be taken into consideration, instead of wet, flat field.
Fertilizing
For swamp dewberry, balanced nutrition fertilizers boost growth and fruit yield, while high nitrogen varieties support vigorous vegetative expansion. Optimal application occurs during active growth, early spring, at one-month intervals. Precise quantities hinge on soil tests, with caution to avoid root burn. Varying seasonally, lesser amounts suit dormant winter. Implementing a slow-release formula ensures sustained nourishment without overfeeding. Always water thoroughly post-application to facilitate nutrient absorption.
Planting Instructions
Generally, swamp dewberry is planted with saplings that are easily purchased from nursery or gardening stores. Avoid swamp dewberry collected in the forest as diseases are a big problem for wild Rubus.
Plant your swamp dewberry in winter or early spring in your garden. Swamp dewberry grows wild where there is much sunlight from above and a wealth of leaf litter, otherwise known as mulch or organic matter in the soil below. Because of this, your planting site is recommended to have ample sunlight and you should have organic matter such as grass clippings readily available. Keep your plants far away from any wild brambles to keep them healthy. Also, plant your swamp dewberry in separate rows. The optimum spacing can be achieved by creating rows about 3 m apart with plants 60 cm apart within each row. Set a trellis on each side and tie the canes onto the trellis line or wire.
Swamp dewberry will spread both rapidly and at long distances. If you do not want it everywhere in your garden, regularly prune it or grow it in containers. You are recommended to find a prickle-free and small variety to plant in pot, which may be handy for you. Use a shallow but large container for it because its roots spread shallowly outward. Potting soil and sunny places are standards for swamp dewberry.
Pruning
Pruning is important for swamp dewberry growers. Prune all canes that bore fruit this year down to the bottom right after harvest. All first-year canes should be cut about half to stimulate lateral growth from the side every late winter or early spring. Remove all suckers and trim overcrowded canes. Swamp dewberry grown in patches must be pruned to ensure that individual canes are not touching to avoid disease infections. Be sure to remove any thinned or pruned canes from the field because old canes left on the ground can harbor disease.
Propagation
Swamp dewberry thrives when propagated during Autumn and Winter using cutting or layering techniques. Moderate difficulty in propagation can be expected. Successful propagation is indicated by root development and new foliage. Diligently maintain cutting or layer moisture for optimal results.
Transplanting
The prime time to relocate swamp dewberry is during the cooler S1-S2 period, also known as the dormant season. This reduces transplant shock and promotes growth. Choose a spot with adequate moisture and partial sunlight. Remember, gentle handling is crucial when moving this delicate perennial.
III. Uses and Benefits
The plant is eaten by birds and many mammals.
A dull blue dye can be created from its berries. The fruit also can be used as an astringent.
The berries are rather bitter for culinary use, and so this plant is generally not cultivated.
IV. Harvesting and Storage
Taste the fruit and it will tell you when it is time to harvest. Ripe fruits will be sweet and juicy. If they are still sour or tart, let them ripen a bit longer. Usually you can start harvesting from mid-summer till mid-fall, according to varieties. You should harvest the fruits when all dews or raindrops are dry to prevent molds. They have a short shelf life, so refrigerate them after harvest without washing. As for some sour species, process them into delicious jams or jellies.