
| 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
|
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
|
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 |
Lepidoptera: Psychidae, Thyridopteryx ephemeraeformis Plants Attacked: Juniper, arborvitae, other cedars, pine, hemlock, spruce, Chinese elm, honeylocust, primarily. Also on crabapple, maple, sycamore, box elder, willow, linden, poplar, and many others. |
May 1, 2009 | 2808-1008 | ||
| 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. |
May 1, 2009 | 2808-1011 | ||
| 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 |
Lepidoptera: Sesiidae, Synanthedon scitula PLANTS ATTACKED: Dogwood, pecan, elm, hickory, and willow |
May 1, 2009 | 2808-1010 | ||
| 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 | ||
| 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 | |||
| 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 | ||
| Major Diseases of Boxwood | May 1, 2009 | 450-614 | |||
| 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
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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 soilWhen 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 | |||
| 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 | |||
| Yuccas, Yucca spp. | Nov 3, 2010 | 3010-1501 |