Rubus tricolor is recommended as groundcover by several proponents of temperate climate forest gardening.

Unfortunately extensive and detailed information about this plant does not seem to be available from published sources. There is an article on Wikipedia which gives fairly good encyclopedic coverage of this species (Link here).

Common names

• Chinese Bramble
• Groundcover Bramble
• Creeping Bramble
• Korean Raspberry
• Himalayan Bramble
• Groundcover Raspberry
• (In China)三色莓 ("sān sè méi")

Forest gardening considerations

The advantages and disadvantages of this plant are discussed below, in the context of forest gardening.

Advantages:

• Weed suppression -- Forms a dense mat through which few weeds will be able to grow.
• Tolerates deep shade -- making it ideal groundcover under trees.
• Tolerates variety of soil types and soil pH.
• Low maintenance.
• Evergreen
• Edible fruit, which can also be used in jams, wines, etc.
• Fast growing & vigorous -- can cover large areas quickly (up to 2 meters per year)
• Generally resistant to pests and diseases -- Grey mould (Botrytis cinerea) may sometimes infect it, and Honey fungus (Armillaria) is a problem for the Rubus genus as a whole.
• Bee plant
• Protects soil -- E.g. from soil erosion.
• Although the stems and leaf petioles are densely bristled, it is not sharp enough that the skin is broken and the plant can be freely handled safely
• Readily propagated -- the plant naturally roots as the stems touch the ground (tip layering). They can be carefully lifted and the stem cut separating it from the rest of the plant.
• Resistant to deer
• Grows back after fire -- thanks to the perennial root system.
• Apart from the edible fruit, berries can also be used to make dye.

Disadvantages:

• Will tend to smother other smaller plants. Although it is typically described as 30-60 cm high and prostrate, the growth habit can also be climbing. Although not quite as smothering as the "European bramble" (i.e. blackberry, Rubus fruiticosus). A spreading mat of R. tricolor can get higher than this as it grows over itself and other shrubs. Consequently time and effort must be spent to prune it back off shrubs, or any shrubs which get partially smothered will see significantly reduced performance. Martin Crawford advises walking on it periodically to keep it to the desired height.^[1]
• Without an established canopy layer, prolific self seeding trees such as ash (Fraxinus excelsior), sycamore (Acer pseudoplatanus) elder (Sambucus nigra) and or hazel will still be able to grow through it.
• Not suitable for small gardens as it will easily take over.
• Usually evergreen but may drop foliage in severe winters. Note also like most Rubus spp. individual canes are typically biennial with new canes emerging form the perennial root system each growing season. Fruiting typically occurs on year old wood.
• Flowering and fruiting may be inconsistent. Do not expect a reliable crop.
• Sources vary in their assessment of the flavour of the berries.
• The plant is quite invasive and once planted it will be very difficult to get rid off. Consider using a rhizomal barrier as described in Edible Forest Gardens vol 2.^[2] Martin Crawford advises cutting back arching growth a few times per year to prevent tip-layering. Alternatively a mown path can keep it within a defined area.^[1]
• It is native to southwest China, and may cause unintended consequences to ecosystems if it becomes invasive in other places (Plants of the World Online) already states it has been naturalized in UK and Ireland.^[3]

References