|Is there a difference between a Japanese boxwood and Winter boxwoods? I thought boxwoods were boxwoods.|
Buxus microphylla koreana - Littleleaf Boxwood or Korean Boxwood - grown for its hardiness from zone 4 through zone 9, but its miniature foliage usually turns a very unattractive, dead-looking yellow-brown in zones 4 to 6 Winters.
Buxus microphylla koreana 'Winter Gem' - has the lightest green foliage color of all the Boxwoods, with new, relatively large foliage emerging lime-green on yellowish stems and maturing by mid-Summer to medium green, with minimal leaf margin burn in Winter; also the fastest growing of all the modern Boxwoods, and often needs to be sheared twice in a growing season if maintained in a formal shrub appearance or as a formal hedge; very popular in zones 4 and 5; 'Winter Gem' may actually be a selection of Buxus microphylla koreana 'Wintergreen'.
Then there's Buxus sempervirens - glossy, larger, dark green Winter foliage is popular in Southern regions with many cultivars, but usually only cold hardy from zones 6 to 8
Buxus sempervirens 'Vardar Valley' - the standard cold-hardy cultivar for this species, which matures at 3' tall by 5' wide and is hardy through zone 5.
Buxus microphylla koreana x Buxus sempervirens - the "Green Series" consists of Canadian hybrids developed in Southern Ontario of these two species, useful from zones 5 to 8:
Buxus 'Green Gem' - 2' tall by 2' wide
Buxus 'Green Mound' - 3' tall by 3' wide
Buxus 'Green Mountain' - 5' tall by 3' wide, naturally pyramidal, an alternative evergreen to replace the overused Dwarf Alberta Spruce (Picea glauca 'Conica'), which is very prone to disease and pest problems with age
Buxus 'Green Velvet' - 3' tall by 3' wide.
Hope this clarifies things for you.