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Trees, Shrubs, & Groundcovers

Title Summary Date ID Author(s)
24 Ways to Kill a Tree

There is a tremendous diversity of herbaceous perennial plant species being grown for both the retail and landscaping sectors of the industry. Because of the diversity in species grown, there is much more unknown about perennials production than is known. Growth regulation is of particular concern. In production settings, as well as in retail locations, herbaceous perennials grown in pots tend to stretch and become leggy or simply overgrow their pots before their scheduled market date. These plants are less marketable, and harder to maintain. Many growers resort to pruning, which is not only costly in terms of labor, but also delays plant production two to four weeks.

May 1, 2009 430-210
A Guide to Successful Pruning, Decidous Tree Pruning Calendar
Deciduous Tree Pruning CalendarLegend:
* = Best time to prune
x = Do not prune except to correct damage, hazards, or structural defects
- = Timing is not critical

Note
  1. Seldom needs pruning - remove multiple leaders, dead and broken branches

  2. Avoid pruning in late winter/early spring due to sap flow (more cosmetic than detrimental)
  3. Avoid pruning from spring through summer due to insect or disease problems
  4. Avoid pruning from October - December due to reduced cold hardiness
  5. Avoid pruning after July because flower buds have set
May 1, 2009 430-460
A Guide to Successful Pruning, Evergreen Tree Pruning Calendar
Legend:
* = Best time to prune
x = Do not prune except to correct damage, hazards, or structural defects
- = Timing is not critical

Note

  1. Seldom needs pruning - remove multiple leaders, dead and broken branches
  2. Don't prune into old wood having no leaves or needles
  3. Prune during growing season to make more compact or dense
  4. To avoid reducing berry production, don't prune during bloom period
  5. Prune to prevent oak wilt infection
  6. Prune to remove cankers
  7. Flower buds set on previous season (old) wood; winter pruning will reduce spring flowering
May 1, 2009 430-461
A Guide to Successful Pruning, Pruning Deciduous Trees

Trees that shed their leaves annually are classified as deciduous. Before getting out your hand pruners, learn some basics about the anatomy, or supporting framework, of a deciduous tree.

The above-ground part of a tree consists of the trunk, scaffold branches, and lateral branches. The leader is the vertical stem at the top of the trunk. Scaffold branches are primary limbs that form a tree's canopy. Secondary branches that emerge from scaffold branches are laterals. Growth comes from buds at the tips of branches (terminal buds), or along branch sides (lateral buds).

May 1, 2009 430-456
A Guide to Successful Pruning, Pruning Evergreen Trees

Evergreen trees have leaves that persist year round, and include most conifers and some broad-leaved trees. Evergreen trees generally need less pruning than deciduous trees.

Conifers are distinguished from other plants by their needle or scale-like leaves, and their seed-bearing cones. Because conifers have dominant leaders, young trees rarely require training-type pruning. The leader is the vertical stem at the top of the trunk. If a young tree has two leaders, prune one out to prevent multiple leader development. Selective branch removal is generally unnecessary as evergreens tend to have wide angles of attachment to the trunk.

May 1, 2009 430-457
A Guide to Successful Pruning, Pruning Shrubs

Understanding the natural "habit" or shape of shrubs will help you determine how to prune them. All shoots grow outward from their tips. Whenever tips are removed, lower buds are stimulated to grow. Buds are located at nodes, where leaves are attached to twigs and branches. Each node produces from one to three buds, depending on shrub species.

May 1, 2009 430-459
A Guide to Successful Pruning, Shrub Pruning Calendar May 1, 2009 430-462
A Guide to Successful Pruning: Pruning Basics and Tools

Pruning is a regular part of plant maintenance involving the selective removal of specific plant parts. Although shoots and branches are the main targets for removal, roots, flower buds, fruits and seed pods may also be pruned.

Pruning wounds plants, but plants respond differently to wounding than do animals. In plants, damaged areas are covered by callus tissue to close wounds. Simply put: animal wounds heal, plant wounds seal.

May 1, 2009 430-455
A Guide to Successful Pruning: Stop Topping Trees!

Topping occurs when the vertical stem (leader) and upper primary limbs (scaffold branches) on mature trees are cut back to stubs at uniform height. Topping is also referred to as heading, stubbing, or dehorning.

May 1, 2009 430-458
American (Fagus grandifolia) and European (Fagus sylvatica) Beeches Feb 21, 2012 HORT-6
American Beautyberry

 

(Callicarpa americana)

Summary:

Foliage: Deciduous broadleaf

Height: 10 feet

Spread: 6 feet

Shape: upright informal habit.

The primary and sole attribute of beautyberry, a large loosely branched shrub, is the showy display of magenta fruits in the fall.

May 1, 2009 2901-1033
American Hornbeam, Carpinus caroliniana Feb 21, 2012 HORT-5
American Yellowood

(Cladrastis kentukea (prior name C. lutea))

Summary:

Foliage: Deciduous broadleaf

Height: 50 feet

Spread: 55 feet

Shape: Vase-shaped

This vase-shaped medium tree has smooth bark and showy white flowers in the spring. It is also quite drought and alkaline soil tolerant.

May 1, 2009 2901-1034
Anthracnose - A Fungal Disease of Shade Trees May 1, 2009 450-604
Austrian Pine, Pinus nigra Nov 3, 2010 3010-1462
Azalea Leaf and Flower Gall May 1, 2009 450-605
Bacterial Leaf Scorch of Landscape Trees Jan 11, 2010 3001-1433
Bagworm Nov 3, 2014 2808-1008 (ENTO-83NP)
Beautybush

(Kolkwitzia amabilis)

Summary:

Foliage: Deciduous broadleaf

Height: 15 feet

Spread: 8 feet

Shape: Upright, arching

The primary and sole attractive aspect of beautybush is a stunning mass of pink, bellshaped flowers in spring.

May 1, 2009 2901-1036
Bigleaf Hydrangea, Hydrangea macrophylla Nov 3, 2010 3010-1463
Black Root Rot of Japanese Holly May 1, 2009 450-606
Botrytis Blight of Peony May 1, 2009 450-602
Boxwood

(Buxus species)

Summary:

Foliage: Evergreen broadleaf

Height: 5 to 20 feet (depending on species and cultivar)

Spread: 5 to 20 feet (depending on species and cultivar)

Shape: Upright mound to round to upright narrow (depending on species and cultivar).

May 1, 2009 2901-1037
Bradford Callery Pear (and other cultivars) Pyrus calleryana ‘Bradford’ Nov 3, 2010 3010-1464
Canadian Hemlock, Tsuga canadensis Nov 3, 2010 3010-1465
Carolina Silverbell, Halesia carolina (formerly H. tetraptera) Nov 3, 2010 3010-1466
Cedars, Cedrus spp. Nov 3, 2010 3010-1467
Characteristics of Common Western Virginia Trees May 19, 2009 420-351
Chastetree, Monk’s Pepper Tree, Vitex agnus-castus Nov 3, 2010 3010-1468
Cherrylaurel

(Prunus laurocerasus `Otto Luyken')

Summary:

Foliage: Evergreen broadleaf

Height: 4 feet

Spread: 8 feet

Shape: Spreading

The species (Prunus laurocerasus) is generally not sold in the U.S. Cultivars of cherrylaurel are low-growing with handsome glossy foliage and white flowers in spring. This species tolerates shade and is used as a border, hedge, and in mass.

May 1, 2009 2901-1038
Chinese Elm (Lacebark Elm), Ulmus parvifolia Feb 21, 2012 HORT-7
Chinese Juniper, Juniperus chinensis Nov 3, 2010 3010-1469
Chinese Pistache, Pistacia chinensis Feb 21, 2012 HORT-8
Colorado Spruce, Picea pungens var. glauca Nov 3, 2010 3010-1470
Common Periwinkle, Lesser Periwinkle, Vinca minor Nov 3, 2010 3010-1471
Cornelian Cherry Dogwood, Cornus mas Nov 3, 2010 3010-1472
Cotoneaster

(Cotoneaster species)

Summary:

Foliage: Deciduous broadleaf (some species are evergreen)

Height: 12 inches to 6 feet

Spread: 2 to 8 feet

Shape: Spreading or upright

Leaves are small and glossy green. Showy small, white/pink, spring flowers are followed by red or black fruit which cover branches in the fall. The fruit display can be quite showy.

May 1, 2009 2901-1039
Cottony Maple Scale

Cottony Maple Scale (Homoptera: Coccidae), Pulvinaria innumerabilis

PLANTS ATTACKED: Maples and dogwood primarily, but also many woody ornamentals.

Nov 14, 2014 2808-1011 (ENTO-89NP)
Crapemyrtle

(Lagerstroemia indica)

Summary:

Foliage: Deciduous broadleaf

Height: 4 to 25 feet (depending on cultivar)

Spread: 5 to 20 feet (depending on cultivar)

Shape: Upright or mound (depending on cultivar)

Glossy, dark green foliage turns yellow, orange, and red in fall. Flowers may be white, pink, red, or purple. Exfoliating bark is ornamental.

May 1, 2009 2901-1040
Creeping Juniper, Juniperus horizontalis Nov 3, 2010 3010-1473
Crown Gall of Woody Ornamentals May 1, 2009 450-608
Dawn Redwood, Metasequoia glyptostroboides Nov 3, 2010 3010-1474
Dogwood Borer
Larvae feed in the inner bark of live, healthy dogwood trees. The damaged area of the trunk or branch swells and eventually the bark will fall off. Leaves turning red prematurely in mid-summer on a lone branch are an early sign of dogwood borers. Infested branches and limbs will die. Dogwood borers often will not kill the tree in the first year, but reinfestation in successive years will. Plants attacked include: Dogwood, pecan, elm, hickory, and willow.
Nov 18, 2014 2808-1010 (ENTO-90NP)
Doublefile Viburnum

(Viburnum plicatum var. tomentosum)

Summary:

Foliage: Deciduous broadleaf

Height: 10 feet

Spread: 12 feet

Shape: Upright with horizontal branching pattern

Doublefile viburnum is a large wide spreading shrub with a horizontal branching habit and a spectacular flower display in spring.

May 1, 2009 2901-1041
Douglasfir, Pseudotsuga menziesii Feb 21, 2012 HORT-9
Drooping Leucothoe

(Leucothoe fontanesiana)

Summary:

Foliage: Evergreen broadleaf

Height: 6 feet

Spread: 6 feet

Shape: Mound with arching branches

Drooping leucothoe is a beautiful and graceful evergreen medium-sized shrub with lustrous, dark green foliage. White bell-shaped flowers bloom in the spring. Its arching branches give it a fountain-like effect. This plant is not suitable for sunny or dry locations.

May 1, 2009 2901-1042
Dwarf Alberta Spruce, Picea glauca ‘Conica’ Nov 3, 2010 3010-1475
Eastern Arborvitae, American Arborvitae, White Cedar, Thuja occidentalis Nov 3, 2010 3010-1476
Eastern Redcedar, Juniperus virginiana Nov 3, 2010 3010-1477
Emerald Ash Borer

Coleoptera: Buprestidae, Agrilus planipennis Fairmaire

Plants Attacked: Emerald ash borer (EAB) attacks all species of ash trees that grow in Virginia. Only Asian species of ash trees have shown any resistance to this pest.

May 1, 2009 2904-1290
English Ivy, Hedera helix Nov 3, 2010 3010-1478
Entomosporium Leaf Spot of Photinia May 1, 2009 450-609
European Cranberrybush Viburnum (Guelder Rose), Viburnum opulus Nov 3, 2010 3010-1479
European Hornbeam, Carpinus betulus Nov 3, 2010 3010-1480
European Larch, Larix decidua Nov 3, 2010 3010-1481
European White Birch

(Betula pendula)

Summary:

Foliage: Deciduous broadleaf Height: 40 to 50 feet

Spread: 25 to 35 feet Shape: Upright

European white birch is a small/medium fast-growing tree with showy white bark and pendulous branch tips (especially when bearing seed). Small, glossy-green summer foliage turns yellow in fall exposing ornamental white bark. This species is considered to be short lived due its susceptibility to pests.

May 1, 2009 2901-1043
Evergreen Azalea

Summary:

Foliage: Evergreen broadleaf

Height: 3 to 8 feet (depending on cultivar)

Spread: 4 to 8 feet (depending on cultivar)

Shape: Upright, spreading

There are hundreds of evergreen azalea cultivars which vary in hardiness, size, form, flower color, time of flowering, and foliage. The primary attractive feature of azaleas is the very attractive and showy flower display in spring.

May 1, 2009 2901-1035
Evergreen Hollies, (Ilex spp.) Nov 3, 2010 3010-1482
Evergreen Rhododendron

Summary:

Foliage: Evergreen

Height: 6 to 15 feet (depending on species or cultivar)

Spread: 5 to 15 feet (depending on species or cultivar)

Shape: Upright, rounded to oval

There are many Rhododendron species and cultivars thereof, as well as hundreds of hybrids.

Rhododendron species come in many sizes and shapes with a wide variety of leaf and flower forms. Azaleas are in the Rhododendron genus and will discussed in another article.

May 1, 2009 2901-1065
Fall Webworm

Distribution and Hosts Native to North America, the fall webworm occurs throughout the United States and southern Canada. Its hosts include more than 100 species of deciduous forest, shade, and fruit trees, with preferences varying from region to region.

May 1, 2009 2808-1013
Fertilizing Landscape Trees and Shrubs

Maintenance programs should be developed for trees and shrubs in both residential and commercial landscapes. A good maintenance program includes monitoring and controlling insect and disease problems, suppressing weed competition, and making timely applications of water, mulch, and fertilizer.

Tree and shrub fertilization is especially important in urban and suburban areas of Virginia where soils have been altered due to construction. These urban soils tend to be heavily compacted, poorly aerated, poorly drained, and low in organic matter. Even where soils have not been affected, fertilization may be needed as part of a maintenance program to increase plant vigor or to improve root or top growth.

May 1, 2009 430-018
Fire Blight of Ornamentals May 1, 2009 450-610
Flowering Crabapple, Malus spp. Nov 3, 2010 3010-1483
Flowering Dogwood, Cornus florida Nov 3, 2010 3010-1484
Flowering Quince

(Chaenomeles speciosa)

Summary:

Foliage: Deciduous broadleaf Height: 10 feet

Spread: 12 feet Shape: Upright

Flowering quince is a large fast-growing shrub whose main merit is showy flowers (red, orange, white, pink depending on cultivar) in early spring. Uses of this species include hedge, shrub border, or mass plantings. Plants have thorns and therefore need careful placement.

May 1, 2009 2901-1044
Foliar Diseases of Dogwood May 1, 2009 450-611
Franklinia, Franklinia alatamaha Nov 3, 2010 3010-1485
Fraser Photinia, Red Tip

(Photinia x fraseri)

Summary:

Foliage: Evergreen broadleaf Height: 20 feet

Spread: 10 feet Shape: Upright

Red tip is a large evergreen shrub. Newly emerging foliage is red and quite showy for a few weeks after which it changes to glossy, dark green. Clusters of white flowers occur in late spring. This plant is widely used in the south as a hedge. Unfortunately, this plant is overused in the landscape and is also susceptible to a serious leaf spot disease.

May 1, 2009 2901-1045
Fusarium Wilt of Mimosa (Albizia julibrissin)

Fusarium wilt is a common and lethal disease of mimosa (Albizia julibrissin)1, also commonly known as silktree. In the United States this disease occurs in the east from New York southward and also in Louisiana, Arkansas and California. Fusarium wilt is caused by the fungus Fusarium oxysporum forma specialis perniciosum. This pathogen causes Fusarium wilt on Albizia species and also on tree-ofheaven (Ailanthus altissima). Fusarium oxysporum f. sp. perniciosum colonizes and clogs the tree's vascular (water-conducting) tissue, and interferes with the movement of plant sap. This results in relatively rapid tree death.

May 1, 2009 2811-1020
Garden Sumacs, Rhus spp. Nov 3, 2010 3010-1486
Giant Arborviatae, Western Arborvitae, Thuja plicata Nov 3, 2010 3010-1487
Ginkgo, Maidenhair Tree

(Ginkgo biloba)

Summary:

Foliage: Deciduous broadleaf Height: 80 feet

Spread: 40 feet Shape: Spreading, a lot of variation in the species

Ginkgo is a large shade tree that is tolerant of adverse growing conditions and has a bright yellow fall foliage color. One should only plant male trees since female trees bear fruit that smell like vomit.

May 1, 2009 2901-1046
Gloomy Scale Sep 25, 2013 ENTO-44NP
Glossy Abelia, Abelia ×grandiflora Nov 3, 2010 3010-1488
Goldenchain tree, Laburnum × watereri Feb 21, 2012 HORT-10
Goldenraintree

(Koelreuteria paniculata)

Summary:

Foliage: Deciduous broadleaf

Height: 40 feet

Spread: 30 feet

Shape: Upright rounded

Goldenraintree is a medium tree with showy yellow flowers in early summer. Flowers are followed by bladder-like fruits that start out light green, turn yellow, and then brown. Fall color can be fair to good depending on the individual tree. This species is quite tolerant of adverse conditions.

May 1, 2009 2901-1047
Green Ash

(Fraxinus pennsylvanica)

Summary:

Foliage: Deciduous broadleaf Height: 60 feet

Spread: 50 feet Shape: Spreading

This large fast-growing tree is very tolerant of adverse conditions. Its fall foliage color is a yellow.

May 1, 2009 2901-1048
Growing Azaleas and Rhododendrons

The spectacular spring flowers of azaleas and rhododendrons make them among the most popular garden shrubs. However, azaleas and rhododendrons are shrubs for all seasons. Throughout the summer and fall the leaves add a pleasing, deep-green color to the garden. Some deciduous azaleas add bright fall color before the leaves drop. In winter, some varieties stand out with large, evergreen leaves.

May 1, 2009 426-602
Heaths (several species of Erica) and Heathers (Calluna vulgaris) Nov 3, 2010 3010-1489
Hemlock Woolly Adelgid Jun 11, 2010 3006-1451
Hinoki Falsecypress, Chamaecyparis obtusa Feb 21, 2012 HORT-11
How to Plan for and Plant Streamside Conservation Buffers with Native Fruit and Nut Trees and Woody Floral Shrubs Sep 4, 2013 ANR-69P
Integrated Pest Management for Plant Diseases in the Home Garden and Landscape, Learning Module I: Integrated Pest Management Feb 21, 2013 PPWS-14NP
Integrated Pest Management for Plant Diseases in the Home Garden and Landscape, Learning Module II: The Plant Disease Triangle Feb 21, 2013 PPWS-15NP
Invasive Exotic Plant Species Identification and Management May 1, 2009 420-320
Invasive Exotic Plant Species: Ailanthus (Ailanthus altissima) May 1, 2009 420-322
Invasive Exotic Plant Species: Autumn Olive (Elaeagnus umbellata) May 1, 2009 420-321
Invasive Exotic Plant Species: Honeysuckle (Lonicera spp.) May 1, 2009 420-323
Japanese Barberry

(Berberis thunbergii var. atropurpurea )

Summary:

Foliage: Deciduous broadleaf

Height: 3 to 8 feet (depending on cultivar)

Spread: 4 to 7 feet (depending on cultivar)

Shape: Upright mound

This medium to large shrub has purple foliage throughout the growing season. Japanese barberry has thorns which may be an advantage (deer proof, pedestrian traffic control) or a liability (injury to pedestrians).

The Virginia Department of Conservation and Resources and the Virginia Native Plant Society have ranked this as a “moderately invasive species” in the mountain, piedmont, and coastal areas of Virginia.

May 1, 2009 2901-1050
Japanese Camillia

(Camellia japonica)

Summary:

Foliage: Evergreen broadleaf

Height: 15 feet

Spread: 10 feet

Shape: Upright, dense Japanese camellia is a dense and formal-appearing large shrub/small tree suitable for USDA plant hardiness zones 7 to 9. Foliage is a glossy, dark-green. Large flowers, ranging from white to pink to red, bloom from winter to spring.

May 1, 2009 2901-1051
Japanese Cryptomeria, Cryptomeria japonica Feb 21, 2012 HORT-12
Japanese Garden Juniper, Juniperus procumbens ‘Nana’ Nov 3, 2010 3010-1490
Japanese Holly

(Ilex crenata)

Summary:

Foliage: Evergreen broadleaf

Height: 2 to 10 feet (depending on cultivar)

Spread: 2 to 10 feet (depending on cultivar)

Shape: Upright or low mound (depending on cultivar)

There are numerous cultivars of Japanese holly. Many are compact, mounded forms with small, spineless, dark-green leaves and black fruit. They are primarily used in mass for borders, backgrounds, and foundation plants.

May 1, 2009 2901-1052
Japanese Maple

(Acer palmatum)

Summary:

Foliage: Deciduous broadleaf. Foliage color, depending on cultivar, varies from green to red to purple to a marble pattern composed of varying combinations of white, pink and shades of green. Foliage shape can vary from the “normal” looking leaf to dissected (leaves with very thin lobes often referred to a “cut leaf” forms). Dissected leaves impart a very lacy look and fine texture to plants. Spring and fall foliage colors are quite vibrant and can be bright red, yellow, chartreuse, or maroon. Red-leaved cultivars will have green leaves if grown in the shade.

May 1, 2009 2901-1049
Japanese Pachysandra, Japanese Spurge, Pachysandra terminalis Nov 3, 2010 3010-1491
Japanese Pagodatree, Sophora

Summary:

Foliage: Deciduous broadleaf

Height: 75 feet

Spread: 75 feet

Shape: Oval to round, spreading

Japanese pagodatree is a medium/large shade tree with showy flowers in summer. Green seed pods, somewhat ornamental, hang on tree until late in the fall. Flower petals can be messy if tree is used near a house, road, or pathway.

May 1, 2009 2901-1053
Japanese Pieris, Pieris japonica Nov 3, 2010 3010-1492
Japanese Stewartia, Stewartia pseudocamellia Feb 21, 2012 HORT-13
Japanese Zelkova, Zelkova serrata Feb 22, 2012 HORT-14
Juniper Tip Blights May 1, 2009 450-601
Katsuratree, Cercidiphyllum japonicum Feb 22, 2012 HORT-15
Kousa Dogwood, Cornus kousa Feb 22, 2012 HORT-16
Lacebark Pine, Pinus bungeana Feb 22, 2012 HORT-17
Leatherleaf Viburnum

Summary:

Foliage: Evergreen broadleaf

Height: 15 feet

Spread: 15 feet

Shape: Upright, multi-stem shrub

This large shrub has dark green leaves that are large, slender, and wrinkled. This species has showy white flowers in late spring. Clusters of red to black berries form (inconsistently) in late summer.

May 1, 2009 2901-1054
Leyland Cypress, ×Cupressocyparis leylandii Feb 22, 2012 HORT-18
Lilacs, Syringa spp. Nov 3, 2010 3010-1493
Littleleaf Linden

Summary:

Foliage: Deciduous broadleaf

Height: 70 feet

Spread: 40 feet

Shape: Upright oval

This medium tree has wonderfully fragrant flowers in June and is tolerant of adverse conditions.

May 1, 2009 2901-1055
Live Oak

Summary:

Foliage: Evergreen broadleaf

Height: 40 feet

Spread: 60 feet

Shape: Spreading

A massive and majestic shade tree with evergreen foliage that is bright olive-green when new and changes to a glossy, dark green when mature.

May 1, 2009 2901-1056
London Planetree

Summary:

Foliage: Deciduous broadleaf

Height: 100 feet

Spread: 80 feet

Shape: Pyramidal in youth, spreading with age

London planetree is a medium/large species that is very tolerant of adverse conditions. It has ornamental which bark flakes off, exposing tan, greenish and creamy white colors.

May 1, 2009 2901-1057
Managing Winter Injury to Trees and Shrubs

It is often necessary to provide extra attention to plants in the fall to help them over-winter and start spring in peak condition. Understanding certain principles and cultural practices will significantly reduce winter damage that can be divided into three categories: desiccation, freezing, and breakage.

May 1, 2009 426-500
Mimosa (Silk-tree or Albizia), Albizia julibrissin Feb 22, 2012 HORT-19
Mountain-Laurel, Kalmia latifolia Nov 3, 2010 3010-1494
Mugo Pine, Pinus mugo Nov 3, 2010 3010-1495
Nandina, Heavenly Bamboo

Summary:

Foliage: Evergreen or semi-evergreen broadleaf

Height: 10 feet Spread: 5 feet

Shape: Upright, cane growth (very little side branching)

Heavenly bamboo is a medium-large upright shrub. In late spring it bears showy white flowers and in the late fall/winter it has attractive reddish foliage (sun) and large clusters of red berries. This species can tolerate full sun or full shade and is drought tolerant. There are several dwarf cultivars that are suitable for small spaces.

May 1, 2009 2901-1058
Native Fruit and Nut Trees and Shrubs of the Virginia Mountains and Piedmont Aug 30, 2012 ANR-23NP
Norway Maple

Summary:

Foliage: Deciduous broadleaf Height: 50 feet

Spread: 50 feet Shape: Oval to round

Norway maple is a medium/large shade tree that is tolerant of adverse conditions. The Virginia Department of Conservation and Resources and the Virginia Native Plant Society have ranked Norway maple as a “moderately invasive species” in the mountain, piedmont, and coastal areas of Virginia.

May 1, 2009 2901-1059
Norway Spruce, Picea abies Feb 22, 2012 HORT-20
Old Fashioned Weigela

Summary:

Foliage: Deciduous broadleaf Height: 9 feet

Spread: 12 feet Shape: upright, spreading

Old fashioned weigela is a large shrub with a coarse texture and showy spring flowers. This plant is best suited for a shrub border. There are several new cultivars which are improved versions (dwarf, foliage and flower characteristics) compared to the species.

May 1, 2009 2901-1060
One-Year Health, Mortality, and Growth in Southeast Virginia of Shortleaf Pine From Three Sources Apr 22, 2013 ANR-28P
Oregon Grape Holly (Manhonia)

Summary:

Foliage: Evergreen broadleaf

Height: 3 to 9 feet (depending on form)

Spread: 5 feet

Shape: Upright, cane growth (very little side branching)

Oregongrapeholly is a slow-growing, medium to large evergreen shrub with lustrous foliage and bright yellow flowers in spring which are followed by robin egg blue fruit in summer.

May 1, 2009 2901-1061
Oriental Arborvitae, Thuja orientalis (also known as Platycladus orientalis) Nov 3, 2010 3010-1496
Pales Weevil

Coleoptera: Curculionidae, Hylobius pales (Herbst)

Plants Attacked: Pales weevil feeds on all pines within its range. It will also feed, although to a lesser extent, on Douglas-fir, fir, hemlock, juniper, larch, northern white-cedar, and spruce.

May 1, 2009 2902-1102
Paperbark Maple, Acer griseum Feb 27, 2012 HORT-21
Phytophthora Root Rot of Rhododendron and Azalea May 1, 2009 450-615
Pin Oak

Summary:

Foliage: Deciduous broadleaf

Height: 70 feet

Spread: 40 feet

Shape: Upright pyramidal in youth, oval at maturity

This large oak has wine-red foliage in the fall.

May 1, 2009 2901-1062
Pine Tortoise Scale, Hemiptera: Coccidae, Toumeyella numismaticum Jan 25, 2011 3101-1529
Planting Trees

Aesthetics. Trees are creatures of beauty and grandeur. They offer beauty in each season with their form, bark, foliage, flowers, fruit, and sometimes fragrance.

In addition to their seasonal variations, they change in size and character over time. Some trees will become quite large and are magnificent just for their size, irrespective of their species.
May 1, 2009 426-702
Powdery Mildew of Ornamental Plants May 1, 2009 450-603
Powdery Mildew-Resistant Woody Ornamentals May 1, 2009 450-616
Privet

Summary:

Foliage: Deciduous broadleaf Height: 4 to 15 feet

Spread: 4 to 8 feet Shape: Bushy

Small, green, summer foliage. When unpruned, pyramidal clusters of small white flowers produce black berries.

May 1, 2009 2901-1063
Problem-free Shrubs for Virginia Landscapes May 1, 2009 450-236
Problem-free Trees for Virginia Landscapes May 1, 2009 450-237
Pruning Crapemyrtles

One of Virginia’s most popular yet mistreated landscape plants is the beautiful crapemyrtle (Lagerstroemia indica, L. fauriei, and L. indica with L. fauriei or L. speciosa hybrids ). Selected and prized for their long summer bloom period (often called the "plant of the 100 day bloom"), cultivars have a range of flower colors, with an interesting seed head following the flower. In addition, crapemrytles have lustrous green leaves that change to bright fall colors, subtle to stunning multicolored bark, and unique winter architecture that makes this plant exceed most landscape choices for four-season interest and appeal.

May 1, 2009 430-451
Red Buckeye, Aesculus pavia Feb 27, 2012 HORT-22
Red Maple

Summary:

Foliage: Deciduous broadleaf

Height: 60 feet

Spread: 60 feet

Shape: Oval to round

Red maple is a fast-growing medium/large shade tree species with a spectacular fall foliage color. It has showy red flowers in the spring. There are many cultivars of this species that vary in form, tolerance of wet conditions, and fall color.

May 1, 2009 2901-1064
Red Twig Dogwoods, Tatarian Dogwood (Cornus alba) and Redosier Dogwood (Cornus sericea) Nov 3, 2010 3010-1497
River Birch, Betula nigra Feb 27, 2012 HORT-23
Rose Rosette Disease Sep 17, 2012 450-620 (PPWS-10P)
Rose of Sharon, Shrub Althea

Summary:

Foliage: Deciduous broadleaf Height: 10 feet

Spread: 6 feet Shape: Upright

Rose-of- Sharon is a large shrub with showy. Relatively large single or double flowers bloom in summer. Flower colors include white, red, purple, violet, and blue.

May 1, 2009 2901-1066
Saucer Magnolia, Magnolia ×soulangeana Feb 27, 2012 HORT-24
Sawara Falsecypress (Japanese Falsecypress), Chamaecyparis pisifera Feb 27, 2012 HORT-25
Scale Insects

Scale insects are a peculiar group and look quite different from the typical insects we encounter day to day. Small, immobile, with no visible legs or antennae, they resemble individual fish scales pressed tightly against the plant on which they are feeding. There are over l50 different kinds of scales in Virginia. Many are common and serious pests of trees, shrubs, and indoor plants.

May 1, 2009 2808-1012
Scarlet Firethron, Pyracantha

Summary:

Foliage: Evergreen broadleaf Height: 15 +feet Spread: 15 feet

Shape: Spreading – can get wild (sprawling) if not pruned

Pyracantha is a large, fast-growing shrub has showy white blooms in spring and a spectacular display of orange/red fruit in the fall. This plant requires pruning since unpruned plants are very rangy looking. Stems have very sharp thorns, thus pruning this plant must be performed with caution. Plants should be not situated where children or pedestrians may encounter stems.

May 1, 2009 2901-1067
Scotch Pine, Pinus sylvestris Feb 27, 2012 HORT-26
Selecting Landscape Plants: Boxwoods

Boxwood is used extensively in the landscape development of homes, gardens, and public grounds in Virginia. Since colonial times, it has been an integral part of the landscape, and many historical gardens in the state are noted for their boxwoods. Today, many people who have colonial architecture select this plant because they feel it fits this style best, but boxwood is also being used with modern or contemporary homes.

Feb 5, 2013 426-603 (HORT-45P)
Selecting Landscape Plants: Broad-Leaved Evergreens

There are a large number of highly ornamental broad-leaved evergreens. However, many of them require special attention if they are to develop into attractive, long-lived plants.

Wide fluctuations in temperature, prolonged dry periods, drying winds, and bright sunshine are not ideal conditions for most broad-leaved evergreens, yet these conditions frequently occur in Virginia. Good soil preparation and a carefully selected location will help ensure the success of these plants. However, the year-round beauty and special effect that they give to the landscape make them well worth the extra care needed to grow them.

May 1, 2009 426-607
Selecting Landscape Plants: Conifers

Conifers, also known as narrow-leaved or needled evergreens, are planted primarily for the attractiveness of their evergreen foliage. The variety of sizes, shapes, and colors available contributes to their popularity.

Conifers range in size from prostrate plants growing only a few inches tall to large trees. Shapes include flat ground covers; horizontal spreaders; upright, pyramidal forms; and even weeping and contorted forms. Foliage color ranges from a gold and cream variegation to all shades of green, gray-green, and blue-green.

May 1, 2009 426-605
Selecting Landscape Plants: Flowering Trees

In the home landscape, flowering trees are secondary in importance to shade trees. The basic elements of framing, background, and shading are provided by shade trees, while flowering trees provide showy and unusual features with their floral beauty and seasonal interest. In addition, many flowering trees have colorful or interesting fruits which may be edible or attractive to birds.

May 1, 2009 426-611
Selecting Landscape Plants: Groundcovers

Ground covers are low-growing plants that spread quickly to form a dense cover. They add beauty to the landscape and, at the same time, help prevent soil erosion. Grass is the best known ground cover, but grass is not suited to all locations. Other ground cover plants should be used where grass is difficult to grow or maintain.

Nov 29, 2012 426-609 (HORT-31P)
Selecting Landscape Plants: Rare and Unusual Trees

There are many tree species that can be successfully grown in Virginia, but are rarely seen in our landscapes. Although not ordinarily recommended or readily available, these trees may be useful to carry out a specific landscape theme, to substitute for an exotic type which is not locally adapted, or may be prized for unusual form, flowers, fruits, bark, or foliage.

May 1, 2009 426-604
Selecting Landscape Plants: Shade Trees

Trees are the basic element for any landscape plan. They set the stage for the entire home grounds design. The type used and their location determine to a great extent what other plantings are appropriate. Providing shade usually requires tall, sturdy, long-living species. Density of foliage, which determines the amount of shading, is important. A tree such as a Norway maple will produce a very dense shade that prevents other plants from growing under it, while a honey locust will produce a light partial shade which is not a hindrance to other plants growing below it. Deciduous trees should be used to shade the south windows of a home in the summer, thus allowing the sun to penetrate in the winter.

May 1, 2009 426-610
Selection and Use of Mulches and Landscape Fabrics

The term "mulch" refers to materials spread or left on the soil surface as protective layers, whether organic or inorganic, loose particles or sheets. Mulches are used primarily to

  1. Suppress competing vegetation (weeds, grass).
  2. Warm the soil to promote earlier spring growth.
  3. Delay soil freezing and prevent frost heaving in winter.
  4. Protect plants from damage by equipment.
  5. Reduce soil erosion and loss.
  6. Hold moisture.
  7. Reduce evaporation and runoff.
  8. Reduce rot and other soil-borne diseases.
  9. Enhance garden and landscape appearance.
  10. Make garden and landscape maintenance easier.
May 1, 2009 430-019
Shore Juniper, Juniperus conferta Nov 3, 2010 3010-1498
Shortleaf Pine: An Option for Virginia Landowners May 1, 2009 420-165
Shrubs: Functions, Planting, and Maintenance

What is a shrub? A shrub is generally considered a multi-stem woody plant that is less than 15 feet tall. Of course, this and other plant size categories are definitions contrived by humans to categorize nature. What is the difference between a large shrub and a small tree? In many cases, there is none. A shrub does not become a tree just because it grows higher than 15 feet. Classifying plants into ground cover, shrub, and tree designations are aids to allow us to conveniently classify and describe plants, albeit with a significant amount of ambiguity.

May 1, 2009 426-701
Smokebush, Smoketree

Summary:

Foliage: Deciduous broadleaf

Height: 15 feet

Spread: 15

Shape: Upright, spreading

Smokebush is a small tree or large shrub depending on how one prunes the plant. Leaves of the species are green. Depending on cultivar; leaves can be purple or yellow during the growing season. After flowering (with small relatively inconspicuous flowers) in spring, clusters of fine filaments associated with flowering give the appearance of “smoke”. Fall foliage color is quite showy.

May 1, 2009 2901-1068
Soil Test Note 20: Home Shrubs and Trees May 1, 2009 452-720
Sooty Mold of Conifers and Hardwoods May 1, 2009 450-618
Sourwood, Oxydendrum arboreum Feb 27, 2012 HORT-27
Southern Magnolia

Summary:

Foliage: Evergreen broadleaf

Height: 80 feet

Spread: 50 feet

Shape: Upright, pyramidal to narrow pyramidal

This is a magnificent large evergreen tree with very large, wonderfully fragrant white flowers in late spring and early summer. There are many cultivars with variations in tree shape and size, flower, and foliage characteristics.

May 1, 2009 2901-1069
Southern Waxmyrtle

Summary:

Foliage: Deciduous broadleaf Height: 15 feet

Spread: 15 feet Shape: Upright, multi-stem

Southern waxmyrtle is a large evergreen shrub or small tree depending on how one prunes it.

This species tolerates wet and dry soils and females have a somewhat showy display of gray berries in the fall/winter.

May 1, 2009 2901-1070
Star Magnolia, Magnolia stellata Feb 27, 2012 HORT-28
Sugar Maple

Summary:

Foliage: Deciduous broadleaf Height: 100 feet

Spread: 80 feet Shape: Oval to round

Sugar maple is a medium/large shade tree with a no less than spectacular fall foliage display.

There are many cultivars; cultivar characteristics include growth rate, form, and fall foliage color.

May 1, 2009 2901-1071
Sweetgum

Summary:

Foliage: Deciduous broadleaf Height: 50 feet

Spread: 30 feet Shape: Pyramidal in youth, round to oval at maturity

Sweetgum is a medium/large tree with very showy fall foliage colors. It tolerates moist to dry

soils. A notable disadvantage is the mess created by the fallen spiny fruit (gum balls).

May 1, 2009 2901-1072
TREE Cookies Etc. Fall 2007 Mar 15, 2013 ANR-59
TREE Cookies Etc. Fall 2008 Mar 15, 2013 ANR-60
TREE Cookies Etc. February 2006 Mar 15, 2013 ANR-56
TREE Cookies Etc. July 2006 Mar 15, 2013 ANR-57
TREE Cookies Etc. May 2007 Mar 15, 2013 ANR-58
TREE Cookies Etc. November 2005 Mar 15, 2013 ANR-55
TREE Cookies Etc. Spring 2010 Mar 15, 2013 ANR-61
TREE Cookies Etc. Winter 2011/12 Mar 18, 2013 ANR-62
TREE Cookies Etc. Winter 2012/13 Jan 22, 2013 ANR-33
The Art of Bonsai

Bonsai is an art form that stems from ancient Asian culture, originating in China and developed by the Japanese. In the 13th century, the Japanese collected and potted wild trees that had been dwarfed by nature. These naturally formed miniatures were some of the first bonsai.

May 1, 2009 426-601
Thornless Common Honeylocust

(Liquidambar styraciflua)

Summary:

Foliage: Deciduous broadleaf Height: 50 feet

Spread: 30 feet Shape: Pyramidal in youth, round to oval at maturity

Sweetgum is a medium/large tree with very showy fall foliage colors. It tolerates moist to dry soils. A notable disadvantage is the mess created by the fallen spiny fruit (gum balls).

May 1, 2009 2901-1073
Tree and Shrub Planting Guidelines
Select trees and shrubs well-adapted to conditions of individual planting sites. Poorly-sited plants are doomed from the start, no matter how carefully they’re planted.

Test soil drainage before planting. Dig a test hole as deep as your planting hole and fill with water. If water drains at a rate of less than one inch per hour, consider installing drainage to carry water away from the planting hole base, or moving or raising the planting site (berm construction).

May 1, 2009 430-295
Trees and Shrubs for Acid Soils

The trees and shrubs on your new home site are growing poorly, so you take samples to the Extension office and the agent suggests a soil test. Test results show that your soil has a pH of 4.5, which is rated as strongly acid. The agent suggests you either take corrective action to raise the pH or grow different plants.

May 1, 2009 430-027
Trees and Shrubs for Overhead Utility Easements

Trees are valuable assets in commercial, private, and public landscapes. Trees add aesthetic beauty, modify and enhance the environment, serve architectural and engineering functions, and increase property and community economic values. These same trees that enhance landscapes, however, are a major challenge for utility companies. Most people have grown accustomed to reliable, uninterrupted electric, telephone and cable service in their homes and offices. Unfortunately, trees are one of the major causes of power outages in areas of overhead utility lines due to direct tree contact with lines, or to trees or tree limbs falling on the lines.

May 1, 2009 430-029
Trees and Shrubs that Tolerate Saline Soils and Salt Spray Drift

Concentrated sodium (Na), a component of salt, can damage plant tissue whether it contacts above or below ground parts. High salinity can reduce plant growth and may even cause plant death. Care should be taken to avoid excessive salt accumulation from any source on tree and shrub roots, leaves or stems. Sites with saline (salty) soils, and those that are exposed to coastal salt spray or paving de-icing materials, present challenges to landscapers and homeowners.

May 1, 2009 430-031
Trees and Water Jul 30, 2012 ANR-18NP
Trees for Parking Lots and Paved Areas

Parking lots and paved areas are essential urban features that tend to be unsightly in their basic form. Municipal ordinances often mandate specific amounts of parking for different types of commercial or residential land use, as well as landscaping for these parking areas. Landscaping in and around parking lots and pavement improves appearance, prevents soil erosion, and reduces carbon dioxide through photosynthesis. Planted areas also reduce storm water drainage problems, reduce the detrimental effects of wind and noise, and enhance human comfort by providing heat-reducing shade.

May 1, 2009 430-028
Trees for Problem Landscape Sites -- Air Pollution

Conditions in urban environments place trees under numerous stresses including compacted soil, soil moisture extremes, and reduced soil fertility. Polluted air is another stress that contributes to the decline of urban trees. Air pollution may cause short-term (acute) damage, which is immediately visible, and long-term (chronic) damage, which can lead to gradual tree decline. Long-term damage may predispose trees to other disorders, making diagnosis difficult.

May 1, 2009 430-022
Trees for Problem Landscape Sites -- Screening

Using trees as living screens can easily enhance living and working spaces. Before selecting trees for screening, first determine the screen's purpose, whether functional or environmental. Screening can be used to define an area, modify or hide a view, create privacy, block wind, dust, salt and snow, control noise, filter light, and direct traffic flow.

May 1, 2009 430-025
Trees for Problem Landscape Sites -- The Walnut Tree: Allelopathic Effects and Tolerant Plants

Walnut is the common name given to twenty species of deciduous trees in the genus Juglans, of which six species are native to the United States. The black walnut, Juglans nigra, which is native to Virginia, grows from Maine west to southern Michigan and south to Texas and Georgia.

May 1, 2009 430-021
Trees for Problem Landscape Sites -- Trees for Hot Sites

Hot landscape sites require special consideration before trees are planted. Trees can survive, and even thrive, in hot sites if the site is prepared correctly, if heat-tolerant species are selected, and if the trees are properly maintained. A variety of different locations and situations qualify as hot landscape sites.

May 1, 2009 430-024
Trees for Problem Landscape Sites -- Trees for Landscape Containers and Planters

Planting trees in aboveground containers and planters is becoming a common practice on sites that are not suited for inground planting. Containers differ from raised planters in that they are usually smaller in volume and moveable, whereas planters are generally larger, and often built as part of the permanent hardscape (paving, etc.). The greatest challenge in selecting trees for containers and planters is in choosing trees that can survive temperature extremes, and that can establish roots in a limited volume of substrate (potting soil). Consider several factors when selecting containers and trees including environmental influences, container and planter design, substrate type, and tree characteristics.

May 1, 2009 430-023
Trees for Problem Landscape Sites -- Wet and Dry Sites

To grow, all trees require air, light, water and nutrients. Some trees can survive over a wide range of climatic and soil conditions, whereas others are very site specific. Both wet and dry sites present establishment and growth challenges, making selection of the right tree for the right site very important.

Know the site's soil

When selecting trees relative to soil moisture, begin by identifying the site's soil type. Soil maps are available for most areas in Virginia (contact your local Virginia Cooperative Extension office). Keep in mind, however, that construction activities (compaction, cut and fill, topsoil removal) may have altered the native soil.

May 1, 2009 430-026
Tuliptree

Summary:

Foliage: Deciduous broadleaf

Height: 90 feet

Spread: 50 feet

Shape: Upright oval

Tuliptree is a very tall, large tree with a straight trunk. It bears beautiful tulip-shaped flowers in May but generally go unnoticed since they high in the tree.

May 1, 2009 2901-1074
Umbrella-Pine (Japanese Umbrella-Pine), Sciadopitys verticillata Feb 27, 2012 HORT-29
Vanhoutte Spirea

(Spiraea x vanhouttei)

Summary:

Foliage: Deciduous broadleaf Height: 10 feet

Spread: 12 feet Shape: Vase-shaped with arching branches

Vanhoutte spirea is a large shrub with graceful arching branches. Its main claim to fame is it abundant and showy display of white flowers in spring. This species is best used in a shrub border or in mass.

May 1, 2009 2901-1075
Verticillium Wilt of Shade Trees May 1, 2009 450-619
Virginia Boxwood Blight Task Force May 20, 2014 PPWS-30
Washington Hawthorn, Crataegus phaenopyrum Feb 27, 2012 HORT-30
White Fringetree, Old-man’s-beard, Chionanthus virginicus Nov 3, 2010 3010-1499
White Oak

Summary:

Foliage: Deciduous broadleaf Height: 100 feet

Spread: 80 feet Shape: Broad-rounded

White oak is a magnificent large spreading tree. This species is somewhat slow growing but is well worth the wait. Do not plant this tree in an area that is apt to be subjected to soil compaction.

May 1, 2009 2901-1076
Winterberry

Summary:

Foliage: Deciduous broadleaf Height: 10 feet

Spread: 10 feet Shape: Upright oval

Winterberry is a large shrub and somewhat informal in character. There are cultivars that are shorter and have a more formal appearance. This native wetland species has very showy bright red fruit (on female plants) in early autumn that persist till February.

May 1, 2009 2901-1077
Wintercreeper Euonymus

Summary:

Foliage: Evergreen broadleaf 

Height: 4 inches as a ground cover 20 feet as a vine

Shape: Spreading Wintercreeper euonymus is a low-growing evergreen ground cover that will climb when it encounters a vertical surface. There are several cultivars which vary in foliage color and height.

May 1, 2009 2901-1078
Woody Florals for Income and Conservation Aug 30, 2012 ANR-22NP
Yaupon Holly Cultivars

Summary:

Foliage: Evergreen broadleaf

Height: 5 to 20 feet (depending on cultivar)

Spread: 3 to 10 feet (depending on cultivar)

Shape: Compact mound

This and several other similar cultivars are used in landscapes as border plants or in mass. This species is very tolerant of most adverse landscape conditions. Some female cultivars have stems laden with very showy persistent red fruit. This species is suited to warmer areas of Virginia (zone 7 and higher).

May 1, 2009 2901-1079
Yews, Taxus spp. Nov 3, 2010 3010-1500
Yield Potential of Native Warm-Season Grasses Grown in Mixture Jul 19, 2013 CSES-55P
Yuccas, Yucca spp. Nov 3, 2010 3010-1501