Siberian Cypress, Russian Cypress, or Russian Arborvitae

(Cupressaceae - Cypress Family)

Form

• small evergreen prostrate shrub, or medium-sized evergreen woody groundcover
• maturing at about 1' tall by 6' wide, although it can get taller and much wider
• radiating mat growth habit
• slow growth rate

Culture

• full sun to partial shade
• best performance occurs in partial sun in moist, well-drained soils, but it is very adaptable to poor, dry, thin soils in sun- and wind-exposed sites
• propagated primarily by rooted stem cuttings
• Cypress Family, with few disease or pest problems
• moderately available in container form
• some sources rate this plant as full shade tolerant and not adaptable to full sun, but experience does not bear these claims out

Foliage

• bright green new growth turns dark green by Summer, then turns dramatically dark brown by late Autumn and remains in this bronzed state throughout the Winter
• leaves consist of awls (intermediate in size between scales and short needles) held tightly against the stems, forming sprays of foliage somewhat similar to those of Arborvitae (hence one of the common names)
• a perimeter group planting of a "normal green" evergreen groundcover or low shrub, or a lighter-colored perimeter rockery, would serve as a fine contrast in Winter to this unusual dark-foliaged plant

Flowers

• monoecious and ornamentally inconspicuous

Fruits

• ornamentally insignificant

Twigs

• thin, brown, and mostly covered by the foliage
• stem termini have downturned ends
• original stems from the center of the young plant slowly elongate to give the plant its diameter, while secondary stems that arise later from the center of the maturing plant give it its tiered height

Trunk

• not applicable

ID Summary

• creeping woody groundcover with bright green Spring foliage, dark green Summer foliage, and dark brown Autumn and Winter bronzed foliage
• stem termini of Microbiota decussata have gracefully downturned ends, whereas stem termini of groundcover Juniperus species have upturned ends

USAGE

Function

• woody groundcover for foundations, wall plantings where it can cascade, group or mass plantings, raised planters, and embankments

Texture

• fine texture
• thick density

Assets

• alternative to groundcover Junipers (some of which are prone to Phomopsis blight)
• fine-textured evergreen woody groundcover that tolerates partial shade
• extreme cold hardiness
• terminal stems with their sprays of foliage have downturned ends, for a graceful, fine-textured effect at the perimeter and center of the plant
• seasonal variation in foliage color
• abscised Autumn leaves can be raked from the plant without damage to it

Liabilities

• brown "evergreen" foliage color in Winter may appear dead to some individuals

Habitat

• zones 3 to 7
• native to Siberia

SELECTIONS

Alternates

• evergreen spreading fine-textured woody groundcovers (Juniperus conferta, Juniperus horizontalis, Juniperus procumbens 'Nana', Picea abies 'Nidiformis', etc.)

Variants

• none available

NOTES

Translation

• Microbiota from the Greek translates as "small Arborvitae", referring to its dwarf conifer habit
• decussata translates as "decussate", referring to the awls (leaves) being opposite on the stems, with consecutive pairs of awls at 90 degree angles to one another (as most opposite leaves are arranged along a stem)

Purpose

• Russian Arborvitae is a woody alternative to spreading groundcover Junipers, or for that matter herbaceous evergreen groundcovers.

Summary

• Microbiota decussata is known as a radiating low shrub that functionally serves as a fine-textured prostrate woody groundcover, undergoing a foliage-color transformation in Autumn to a brown Winter color, performing admirably in full sun to partial shade in dry, wind-exposed sites.