Mahonia eurybracteata 'Minganpi' SWEET WINTER® threadleaf mahonia, Oregon grape holly
size/type
medium-sized shrub,small shrub
usual height
1-1,5m
usual width
1-1,5m
leaves
evergreen broadleaf
colour of leaves
flowers
showy
colour of flowers
blooming time
October-December
location
semi-shade / partial sun
soil type
any (acidic to alkaline)
soil moisture requirements
evenly moist (dislikes drought)
USDA zone (lowest)
7 (down to -23°C)
winter protection
for zone 5+6
for zone 7
categorized
Threadleaf mahonia (Oregon grape holly) is a Chinese taxon formerly known as mahonia confusa. Perhaps only with it rising popularity thanks to newly invented varieties its name was changed to m.eurybracteata. The first successful varieties were Narihira, Soft Caress, and Sweet Winter.
Description of the plant:
SWEET WINTER® is a threadleaf mahonia variety from Minier Nursery in France, found as a naturally occurring mutation in 2005. European patent EU33353 was granted in 2012. It makes much narrower and longer foliage than the Chinese species yet a little bit wider than Soft Caress variety from the USA. The evergreen leaflets are only some 1 cm wide, dark green, partially glossy, gently serrated at margins, soft to touch, and form a compound pinnate frond. In autumn unroll 10-20 cm tall, upright racemes composed of small, bright yellow, slightly fragrant flowers. If pollinated, they are followed by purple blue, edible berries that taste like barberry berries. It grows into a dense shrub about 1.5m tall and wide, offering a fluffy yet more compact habit compared to Soft Caress variety. It loves a bit of sun and midday shade, or partial shade all day long. Plants grown in full sun set more flowers but are prone to sunscorch in colder climates. Still, they regenerate readily after spring pruning. This mahonia will be a jewel among other large-leaved evergreens and a fine-textured understory of mid-sized trees providing filtered sunlight.
Threadleaf mahonia requires fertile soil of any pH (acidic, neutral, and alkaline). It likes constantly moist but well-drained soil. We experienced the best results with acidic soil where its foliage produced the richest colour. It does not like drought so keep it mulched all year long. We have tested its hardiness to -20 °C (USDA zone 6) so far and continue with trials as we believe it will take a few degrees lower.
Last update 30-11-2020
