Care and How-To Articles - Trees and Shrubs
While spring is the traditional planting season in Iowa, late summer and early fall (mid-August to early October) is an excellent time to plant many landscape plants. Below is advice on fall planting of trees, shrubs, perennials, annuals, spring-flowering bulbs, lawns, and vegetables.
Boxwood (Buxus sempervirens) is a dark green evergreen native to southern Europe and northern Africa. It usually grows to a height of three to four feet in Iowa's climate and is popular for borders and hedges because of its dense, dark green foliage. Boxwood requires fertile, well-drained soils and prefers wind protection if grown on an exposed site.
Winter can be tough on boxwoods in Iowa. Over the winter, boxwood may see extensive damage or even die. Sometimes, entire hedges will succumb. Exceptionally low temperatures are to blame in most cases. Boxwoods are marginally hardy in Iowa and can suffer from foliar burn and twig kill in severe winters in exposed locations. Leaves turn brown and twigs die back.
Newly planted trees can eventually add great color and valuable cover to any landscape. But winter’s harsh conditions can hamper, delay or completely derail their development. There are several things you can do to help these new additions to the landscape survive and thrive in colder temperatures.
Water Newly Planted Trees Until the Ground Freezes
The roots of trees continue to grow until the ground freezes in winter. If the weather is dry, continue to water newly planted trees until the soil freezes. Small trees usually require watering for one or two growing seasons. It may be necessary to periodically water large trees for three or four years.
If a tree, shrub, or perennial cannot be planted in its final spot before winter arrives, you will need to take steps to make sure it survives the winter while still in the container.
Container-grown plants should not be left outdoors above ground over the winter months. The roots of most trees, shrubs, and perennials are far less cold hardy than their aboveground stems or trunks. Container-grown plants are growing in relatively small amounts of potting soil. The temperature of the potting mix may drop into the single digits if container-grown plants are left above ground in winter. Single-digit temperatures may damage or destroy the root systems of plants.
Some plants in the landscape need a little extra protection to make it through the winter months. Here is what you need to know to successfully overwinter plants in Iowa.
When a summer heat wave arrives, it can be stressful for the plants and gardeners alike. The plants of your landscape will require a little more TLC to make it through periods of extreme heat. Below are a few tips to protect your lawn, garden, and landscape when temperatures soar.
Watering is one of the most frequent tasks performed in any garden or landscape. Proper watering utilizes water responsibly, reducing evaporation and runoff. There are many ways to make the process easier and better for the gardener and the plants. Use the tips below to water the perennials, annuals, containers, hanging baskets, lawns, trees, shrubs, and vegetables in your landscape.
Hydrangeas are popular shrubs for the home landscape. Their large, elegant flowers charm homeowners and visitors alike throughout the summer months. An added bonus to most hydrangea flowers is that they make excellent cut and dried flowers. You can bring the blossoms inside to brighten the indoor landscape.
In the past decade, there has been an explosion of new cultivars with varying flower colors and shapes. With all this variety there is likely a hydrangea (or two) that will work in your landscape.
Several hydrangea species can be grown in Iowa. Two species (smooth hydrangea and panicle hydrangea) are easy-to-grow, reliable performers. The others can be a bit more challenging.
For shrubs to perform well in the landscape, home gardeners must prune them properly. Proper pruning helps maintain plant health, control or shape plant growth, and stimulate flower development.
Four species of hydrangea are commonly grown in Iowa. Pruning practices are based on the growth and flowering characteristics of each species.
Winter is a challenging time for trees and shrubs. Animals, wet snow, drying winds, sunscald, and deicing salts can damage trees and shrubs in the home landscape. Fortunately, steps can be taken to minimize damage to trees and shrubs in winter.
Newly-planted trees need active and frequent care during the entire establishment period. In USDA hardiness zones 4 and 5, the establishment period lasts about 12 months per inch of trunk diameter. For a two-inch caliper tree, this translates into a 24-month establishment period. Good cultural practices during this period help reduce transplant stress and create a favorable environment for tree growth.
Consistent and proper care during the establishment period is the most important thing you can do to succeed with your new tree.
Spring often gets all the attention when it comes to flowers, especially flowering trees. Yet, there are several tree species that bloom in early to late summer. In addition to their late bloom, these trees en have other ornamental features that make them deserving of a spot in your landscape.
Weedy vines can be some of the most difficult to control weeds in the garden. They are fast-growing, getting very large in a relatively short amount of time and often climb and cover other garden plants. These tenacious plants climb by twining, rambling, or utilizing specialized structures like tendrils or aerial roots. They are often botanically classified as eudicots and can be woody or herbaceous, perennial or annual. Examples of vining weeds include poison ivy, honeyvine milkweed, bindweed, and Virginia creeper. If left to grow, they can smother other plants, blocking light and killing the desirable plant.
Woody weeds are trees and shrubs that have woody plant tissue. Examples of woody weeds include tree of heaven, bush honeysuckle, and poison ivy.
These weeds can be particularly difficult to manage, especially if they grow large.
Keeping ahead of weeds and controlling them when they are small is essential for good weed management. This requires persistence throughout the entire growing season to remove weeds as they emerge.
Anyone can plant a tree, but to ensure success, sound installation practices must be followed. Use this guide to plant any tree.
Organic mulches serve several important functions in gardens and landscape plantings.
These many benefits make the use of mulch very beneficial in a wide range of garden settings. When choosing which organic mulch to use, consider availability, cost, appearance, function, and durability.
Lilacs are one of the most cherished and adored of all flowering shrubs. They are noted for their beautiful blossoms and fragrance. Lilacs are available in a wide range of colors. Though they offer mainly one season of interest, their spring flower displays are greatly appreciated after a long, hard winter.
Learn about the selection and care of lilacs in Iowa.
After a long (seemingly endless) winter, most Iowans are eagerly looking forward to spring. Sure signs of spring are the emergence of tulips and daffodils, the greening of lawns, and the blooming of early spring-flowering shrubs. Though it may be hard to believe, the flowers of the following shrubs will begin to appear within the next few weeks. To get your spring off to a colorful start, plant some early spring-flowering shrubs in the landscape.
There are about 45 species of dogwoods. Most are shrubs or small trees. Several dogwoods are valuable additions to home landscapes. A list of suggested dogwoods for Iowa, along with a brief description of each, is provided below.
Locations with moist to wet soils are not suitable for many shrubs. However, these sites are home to several native shrubs. A list of native wetland shrubs, along with a brief description of each, is provided below.
Shrubs are valuable assets to a home landscape. Shrubs are often planted for their ornamental characteristics, such as flowers, colorful fall foliage, or attractive fruit. They also can provide privacy, block views, and attract wildlife. For shrubs to perform well in the landscape, home gardeners must prune them properly. Proper pruning helps to maintain plant health, control or shape plant growth, and stimulate flower production.
Suckers are vigorous upright growing stems that form at the base of a tree or from the root system causing stems to appear inches or feet from the base of the trunk. They are problematic because they can reduce flowering and fruiting, alter the form of the tree, harbor pests and diseases, and look unsightly.
Learn about what causes suckers to form and how they can be managed in the home landscape.
Many deciduous shrubs in the home landscape may be propagated by softwood cuttings.
Trees that can be propagated from softwood cuttings include willow, maple, ginkgo, elm, crabapple, linden, birch, sweet gum, and redbud.
Shrubs that can be propagated from softwood cuttings include lilac, forsythia, weigela, dogwood, ninebark, and viburnum.
Time of Year to Take Softwood Cuttings
Softwood cuttings are taken in late May through early July from the current season’s growth. Cutting material should be flexible but mature enough to snap when sharply bent.
During the cold, gray days of winter, most Iowans look forward to the vibrant colors of spring. The explosion of colors in the home landscape in spring include tulips, daffodils, Siberian squill, other spring-flowering bulbs, the greening of lawns, and flowering trees. The following are excellent small, spring-flowering trees for the landscape.
To successfully establish trees in the home landscape, it's important to follow proper planting techniques. Follow these steps to plant and care for containerized or balled and burlapped (B&B) trees.
After planting a new tree, sometimes you will see decline, dieback, or even death of the young tree. When trying to determine the primary cause of the problem, several factors need to be given consideration.
Learn about the factors that you need to investigate to determine why a newly planted tree is failing.
Trees are important fixtures in the urban and rural landscape. We value above-ground parts of trees for their spring flowers, cooling shade in summer, and vibrant leaf colors. But healthy root systems below ground are vital for tree vigor and longevity. Roots are responsible for water and mineral nutrient uptake, energy storage, and anchorage. If for any reason tree roots are damaged, tree health will be jeopardized. Grade changes - both raising and lowering the soil grade - in the root zone of a tree can be fatal.
In Iowa, the weather in spring is often erratic. Below-freezing temperatures in April and May can follow unseasonably warm weather in late March and early April. The cold spring temperatures can affect plants in gardens and home landscapes. The good news is that cold temperatures shouldn't affect most plants long-term. How to manage cold temperatures and the damage it can cause to trees, shrubs, fruit trees, spring bulbs, perennials, vegetables, and other plants is provided below.
Winter can be tough on trees, both newly planted and established. Winter conditions can cause damage in several ways. Conifers and other evergreen plants are particularly prone to damage over the winter. Often the damage that occurs over winter does not become apparent until the following spring. Some symptoms you might see are needle browning (sometimes yellowing), cracking or death of the bark, and animal feeding.