Growing Shrubs in Zone 4 Gardens
Growing shrubs in zone 4 is not much different than growing shrubs in any zone. Cold hardy shrubs will benefit from an extra heap of mulch around the root zone in late fall for insulation in winter. Most shrubs can be pruned back when they go dormant in late autumn, except for evergreens, lilacs and weigela. Spirea, potentilla and ninebark should be cut back hard every couple years to keep them full and healthy. All evergreens should be watered well each fall to prevent winter burn.
Bushes That Grow in Zone 4
The following shrubs/small trees are suitable for growing in zone 4 climates.
Spring Flowering Shrubs
Flowering Almond (Prunus glandulosa) – Hardy in zones 4-8. It prefers full sun and is adaptable to most soils. The bush grows between 4 and 6 feet (1-2 m.) tall, and nearly as wide. Small, double pink flowers cover the plant in spring. Daphne (Daphne burkwoodi) – The cultivar ‘Carol Mackie’ is hardy in zones 4-8. Provide full sun to part shade and well-draining soil. Expect fragrant, white-pink flower clusters with growth of 3 feet (91 cm.) tall and 3-4 feet (91 cm.-1m.) wide. Forsythia (Forsythia sp.) – While most are fairly tolerant in zones 4-8, you’ll find ‘Northern Gold’ to be one of the hardiest of these commonly planted shrubs. These yellow-blooming shrubs enjoy plenty of sun and without pruning can reach 6-8 feet (2 m.) tall with a similar spread. Lilac (Syringa sp.) – Hardy in zones 3-7, there are hundreds of varieties of lilac well suited to zone 4. Size of plant and color of highly fragrant flowers differs by variety. Mock orange (Philadelphia virginalis) – Hardy in zones 4-8, this shrub is highly fragrant with white flowers. Purpleleaf sandcherry (Prunus cisterns) – Though its purple foliage provides interest from spring through summer, this shrub is most impressive in spring when the light pink flowers beautifully contrast the dark foliage. Hardy in zones 3-8, but can be short lived. Quince (Chaenomeles japonica) – This zone 4 hardy plant provides vivid shades of red, orange or pink flowers just before foliage growth begins in spring. Weigela (Weigela sp.) – There are many varieties of weigela hardy in zone 4. Foliage color, flower color and size depend on variety and some are even repeat bloomers. All types have trumpet-shaped flowers that attract pollinating insects and hummingbirds.
Summer Flowering Shrubs
Dogwood (Cornus sp.) – Size and foliage color depend on variety, with many types hardy in zones 2-7. While most provide white flower (or pink) clusters in early spring, many also put on an early summer show. Many dogwoods can also add winter interest with bright red or yellow stems. Elderberry (Sambucus nigra) – The Black Lace variety is hardy in zones 4-7, providing pink clusters of flowers in early summer, followed by edible black-red fruit. Dark, lacy black-purple foliage is attractive in spring, summer and fall. Makes an excellent low maintenance alternative to fussy Japanese maples. Hydrangea (Hydrangea sp.) – Like dogwoods, the size and flower color depend on variety. An old fashioned favorite, hydrangeas have large flower clusters from mid-summer to frost and many types are now suitable for zone 4 regions. Ninebark (Physocarpus sp.) – Mostly planted for foliage color but also provide attractive white-pink flower clusters in mid-summer. Potentilla (Potentilla fruticosa) – Potentilla blooms from early summer through fall. Size and flower color depend on variety. Smoke tree (Cotinus coggygria) – Hardy in zones 4-8, give this one full sun for purple foliage varieties and part shade for golden types. This large shrub to small tree (8-15 feet tall) (2-5 m.) produces large wispy flower plumes that look somewhat like smoke in mid- to late summer with the foliage attractive all season long. Spirea (Spirea sp.)- Hardy in zones 3-8. Full Sun – Part Shade. There are hundreds of varieties of Spirea that can be grown in zone 4. Most bloom in spring- midsummer and have colorful foliage that is attractive in spring, summer and fall. Low maintenance shrub. St. John’s wort ‘Ames Kalm’ (Hypericum kalmianum) – This variety is hardy in zones 4-7, reaches about 2-3 feet (61-91 cm.) tall and wide, and produces masses of bright yellow flowers in midsummer. Sumac (Rhus typhina) – Primarily grown for its green, yellow, orange and red lacy foliage, Staghorn sumac is often used as a specimen plant. Summersweet (Clethra alnifolia) – Hardy in zones 4-9, you’ll enjoy this shrub’s highly fragrant flower spikes in midsummer, which also attract hummingbirds and butterflies. Viburnum (Viburnum sp.) – Size depends on variety with many having white clusters of flowers in early summer, followed by fruit that attracts birds. Many varieties are hardy in zone 4 and also have orange and red fall color. Dappled willow (Salix integra) – Hardy in zones 4-8 this very fast growing shrub is primarily grown for its pink and white foliage. Trim frequently to promote this colorful new growth.
Shrubs for Fall Color
Barberry (Berberis sp.) – Hardy in zones 4-8. Full Sun- Part Shade. Has thorns. Size depends on variety. Foliage is red, purple or gold depending on variety, throughout spring, summer and fall. Burning bush (Euonymus alata) – Hardy in zones 4-8. Full Sun. 5-12 feet (1-4 m.) tall and wide depending on variety. Grown primarily for its bright red fall color.
Evergreen Shrubs in Zone 4
Arborvitae (Thuja occidentalis) – Found in tall columnar, conical or small rounded varieties, the large shrubs to small trees provide green or gold evergreen foliage year round. Boxwood (Buxus sp.) – Hardy in zones 4-8, this popular broadleaf evergreen makes a great additions to gardens. Size depends on variety. False cypress ‘Mops’ (Chamaecyparis pisifera) – The shaggy, thread-like gold foliage gives it this interesting shrub its common name and is a good choice for zone 4 gardens. Juniper (Juniperus sp.) – Size and color depends on variety, with many hardy from zone 3-9. Can be low and sprawling, medium and upright, or tall and columnar depending on which types you choose. Different varieties come in blue, green or gold. Mugo pine (Pinus mugo) – Hardy in zones 3-7, this somewhat small evergreen conifer tops out anywhere from 4-6 feet (1-2 m.) tall, with dwarf varieties also available for smaller areas.
