Snow-on-the-Mountain, Bishop's Weed, or Goutweed

(Apiaceae [also known as Umbelliferae] - Parsley Family)

Form

• medium-sized herbaceous perennial groundcover
• foliage rises to 1' high from the many basal crowns, while the plant spreads indefinitely at its perimeter; flowers may reach 1.5' in height on their long thin stalks in early Summer, but are often sparsely borne
• upright mat growth habit
• medium growth rate (at its perimeter by underground stolons)

Culture

• partial sun to full shade
• performs best in partial shade in moist, well-drained soils of moderate fertility, but is extremely tolerant of a wide range of soils and soil pHs; however, it strongly prefers a well-drained soil, and will leaf scorch under conditions of heat, drought, and excessive sun
• propagated by separation of stolon-attached daughter plants from the colony, root segments, crown division, or seeds
• Parsley Family, with no significant diseases or pests, but leaf scorch will almost always occur if sited in partial sun to full sun, or if drought occurs during the Summer
• commonly available in flats or containers
• Summer-scorched foliage can be sheared or mowed-off to promote new foliage emerging from the crowns and re-establishing within a month
• flowers stalks can be cut off during or after the flowering period to encourage the observer's eye to focus on the attractive variegated foliage, and to prevent seed set
• occasional non-variegated sports should be immediately dug up and removed, as they will be even more vigorous and soon predominate in the colony of groundcover
• digging up a colony of the plant only serves to break apart the root system and rejuvenate the colony, resulting in a flush of new growth within two months; the best method of control is to hit the plants hard as the new foliage expands in Spring with an application of broad-spectrum herbicide, and to repeat this until all new flushes of growth are beaten back; old foliage in mid- to late Summer has a thick cuticle and will not respond to herbicide, unless it is mowed off and new foliage emerges

Foliage

• ternate (3 leaflets per compound leaf) or biternate (7 or 9 leaflets per compound leaf, with the lower leaflets sometimes fused together) foliage rises directly from the crown
• ovate serrated leaflets are a pale gray-green with white- or cream-edged variegation
• prone to leaf scorch in Summer, especially under sunny and/or dry conditions, irrespective of whether the variegated foliage or solid green foliage form is present
• dying back to the ground in late Autumn without any change in fall coloration

Flowers

• white, flat-topped, finely-textured inflorescences are similar in appearance to those of Wild Carrot (also known as Queen Anne's Lace (Daucus carota), from the same Parsley Family), flowering in June, on peduncles to 1.5' high by 2" wide
• inflorescences are noticeable up-close but not from a distance, since the white inflorescences get lost among the leaf variegation, and actually detract from the primary ornamental appeal of the variegated foliage

Fruits

• ornamentally insignificant; the small brown seeds are borne on flat-topped fruiting stalks, and should be deadheaded after flowering to prevent self-sowing

Twigs

• not applicable

Trunk

• not applicable

ID Summary

• ternate or biternate basal foliage emerges in early Spring, typically as creamy-white variegated foliage, very attractive but prone to leaf scorch at some time during the drought of Summer, with the plant being very invasive, forming a broad colony that spreads readily at its perimeter by underground stolons; flowering occurs as wispy flat-topped white inflorescence on long stalks

USAGE

Function

• edging, border, foundation, raised planter, or focal point groundcover
• should only be used in a restricted root zone area (for example, between a sidewalk and a foundation) due to its rapid spread out-of-bounds by underground invasive stolons

Texture

• medium texture in foliage
• thick density in foliage

Assets

• variegated foliage (the predominant form in cultivation) lightens up shady spots
• highly adaptable to poor soils
• aggressive spreading growth (if this is desired)

Liabilities

• very invasive (when its root zone is unrestricted)
• Summer leaf scorch under sunny and/or dry conditions
• sparse white inflorescences may detract from the variegated foliage

Habitat

• zones 4 to 8
• native to Europe

SELECTIONS

Alternates

• other variegated groundcovers (Ajuga reptans 'Burgundy Glow', Hedera helix 'Gold Heart', Liriope 'Monroe's White', Pachysandra terminalis 'Variegata', Vinca minor 'Ralph Shugert', etc.)

Variants

• Aegopodium podagraria 'Variegatum' - Snow-on-the-Mountain - the standard form available, with leaflet margins distinctly creamy to white and making a good contrast to the otherwise gray-green foliage in shady situations

NOTES

Translation

• Aegopodium from the Greek translates as "goat little foot", referring to the fact that the plant was once thought to cure gout.
• podagraria translates as "foot chain" for its leaf shape and again its supposed ability to treat gout.

Purpose

• Snow-on-the-Mountain is one of the most common variegated deciduous groundcovers, especially for Northern United States climates.

Summary

• Aegopodium podagraria 'Variegatum' is a poor soil-tolerant, variegated deciduous groundcover which performs best in partial shade in evenly moist soils, and is vigorous in its establishment when given a large shady area to cover.