Care and How-To Articles
Great gardens are colorful throughout the growing season. Many perennials can be grown in Iowa to provide flowers and interest year after year in late summer and fall. These perennials are great additions to the Iowa garden to get plenty of late-season blooms.
Usually, we don't think of herbaceous perennials as having fall color. However, there is a select group of perennials that might surprise you with their brilliant foliage colors in fall.
Those perennials listed below have notable yellows, reds, oranges, and purples in their late-season foliage providing at least a couple weeks of good fall color every year.
Shedding, peeling, or splitting bark on trees in the landscape can be a concerning sight.
Understanding what is causing the bark loss is an important first step to preventing further damage in the future.
Along with mums and pumpkins, ornamental (occasionally referred to as "Indian corn") is often used to decorate homes in the fall. Ornamental corn can be purchased at farmer’s markets, roadside stands, craft shows, garden centers, and other locations. Ornamental corn can also be grown in large home gardens.
Succulents are a diverse group of plants and there are many different species to choose from. Outlined below are common and popular species of succulents. Species are listed in groups based on their overall growth habit or use. Within each group species are listed by relative size from smallest to largest. For some genera or species, the size varies widely.
Succulents have relatively few pest and disease issues. Scout plants frequently to catch problems early and treat them before they become severe.
Over Watering | Under Watering | Root Rot | Insufficient Light | Sun Damage | Mealybugs | Dead Lower Leaves | More Information
Most succulents are easy to propagate vegetatively by offsets, stem cuttings, or leaf cuttings. The type of propagation you choose depends on the species of plant and how it grows.
Offsets & Division | Stem Cuttings | Leaf Cuttings | Propagation Method by Species | More Information
Gardeners are occasionally surprised to find small, round, green, tomato-like fruit on their potato plants. These fruit are not the result of cross-pollination with tomatoes. They are the true fruit of the potato plant. The edible tubers are enlarged, underground stems.
Summer is often the time of year Phytophthora root rot starts showing up in rhododendron and azalea plantings. The fungus is favored under extremely wet conditions and in heavy, poorly drained soils. The wet spring may have aggravated the condition more this year.
Phytophthora root rot of rhododendrons is caused by several species of Phytophthora. The pathogens, primarily P. connamoni, P. citriocola and P. cactorum, are soilborne and invade roots under wet conditions. Most cultivars of rhododendrons are highly susceptible to attack by Phytophthora.
There are several Hibiscus species that grow well in Iowa. Growing hibiscus can be confusing to Iowa gardeners because the three most common species vary greatly in flower, habit, and cold hardiness. But all three are worthy of consideration in the outdoor or indoor landscape.
While annual sunflowers (Helianthus annuus) are the species grown for edible seed and oil production, the majority of Helianthus species are perennials. These native species can be wonderful additions to home landscapes. Learn more about perennial sunflowers below.
From time-to-time homeowners choose to renovate their homes. Established strawberry beds should be renovated every year!
Benefits of Renovation
The diversity of summer-blooming perennials is amazing and often attracts a diverse group of pollinators to the landscape. Learn more about the many perennials that bloom in Iowa during the heat of the summer.
Many trees and shrubs thrive in Iowa's fertile, well-drained soils. Most trees and shrubs, however, don't like wet soils. Fortunately, some plants tolerate wet soils better than others.
When selecting trees and shrubs for the home landscape, gardeners should select plants suitable for the site. Wet sites can be a challenge. However, the trees and shrubs listed below will perform well in wet soils.
When selecting perennials, choosing plants that are suitable for the site is important. Garden sites can vary tremendously. Some areas are hot and dry. Others are wet. Wet sites can be challenging, but they also provide gardening opportunities. The following perennials perform well in moist to wet soils.
In addition to providing color in the garden, perennials can be used as solutions to problem spots in the home landscape. Many landscapes have hot, dry sites that are difficult for many perennials. Drought-tolerant perennials are the perfect solution for these dry sites. Below is a list of some perennials that, once established in the garden, will tolerate or even thrive in dry conditions.
Fernleaf Yarrow
Most annual flowers require consistent moisture throughout the growing season for adequate growth and bloom. However, there are a few annuals that perform well in dry weather. When other annuals suffer from a lack of moisture, these annuals will flower profusely without a significant rise in the water bill.
All of these drought-tolerant annuals will require water initially to establish a good root system. Once established, however, they require little watering. All perform best in full sun with well-drained soils.
Don't let dry weather stop you from having flowers in your garden. These annuals will tolerate the heat and drought better than we will.
When selecting annuals, perennials, shrubs, and trees, choose plants that are adapted to the growing conditions at the planting site. Most landscape plants prefer moist, well-drained soils in full sun. However, there are plants that will tolerate more difficult sites.
Lists of annuals, perennials, shrubs, and trees that tolerate dry soils, wet soils, and partial shade are provided below.
Some individuals consider shady sites to be problem areas in the home landscape. However, shady areas actually provide opportunities for home gardeners. Wise plant selection can turn a shady site into an attractive landscape area. A number of trees and shrubs can be successfully grown in partial shade. (Partially shaded sites receive 3 to 4 hours of direct sun but are in shade the rest of the day.)
Selecting and planting shade tolerant trees and shrubs, along with suitable annuals and perennials, can transform bare shady areas into attractive landscape sites. Below is a list and brief description of trees and shrubs adapted to partial shade.
Many plants grown in the home landscape require consistent moisture throughout the growing season without staying too wet. However, there are a few annuals, perennials, shrubs, and trees that perform well in wet soil conditions. This includes low-lying areas, water edges, or soils with poor drainage. Many of these plants will also tolerate periodic flooding.
Many plants grown in the home landscape require consistent moisture throughout the growing season. However, there are a few annuals, perennials, shrubs, and trees that perform well in dry weather or dry soil conditions. All of these drought-tolerant plants will require water initially to establish a good root system. Once established, however, they require little watering and will make it through the driest of years with little damage.
Determining when to harvest vine crops, such as melons, squashes, and cucumbers, is not always easy. While some vegetables like tomatoes exhibit clear signs, the proper time to harvest other crops may require a little more knowledge and experience. Learn more about the guidelines for harvesting and storing various vine crops including watermelon, cantaloupe, cucumbers, summer squash, winter squash, pumpkins, and gourds.
Vine crops (cucumber, muskmelon, watermelon, and squash) are some of the most popular vegetables in the home garden. While vine crops are easy to grow, home gardeners are occasionally disappointed in crop yields. Poor fruiting of vine crops may be due to the plant's flowering habit, poor pollination, or blossom-end rot.
Cucumbers (Cucumis sativus) are a vegetable garden staple. These vining plants are in the gourd family (Cucurbitaceae) and include not only cucumber, but squash, pumpkin, gourd, watermelon, and cantaloupe. This member of the "vine crops" grows on long trailing vines that can take up quite a bit of space in the home vegetable garden, so plan accordingly if you are thinking of adding them to your home garden. Cucumbers can be successfully grown on trellis systems to save space and make harvest easier.
Wood chips and shredded bark are commonly applied to landscape areas to control weeds and conserve soil moisture. Wood chips and shredded bark are organic matter. The decaying organic matter provides an ideal environment for some strange-looking fungi or fungal-like organisms when weather conditions are favorable. Fungi that occasionally grow in landscape mulches in Iowa include stinkhorns, slime molds, and bird’s nest fungi.
This page highlights shade tree options well-suited for the Iowa landscape. While it doesn't include every possibility, this list provides descriptions of many wonderful species and cultivars proven to be good options for many Iowa homeowners.
Roses have a number of potential problems that can make them more difficult to grow. Planting them in a good garden location and selecting a winter-hardy and naturally disease-resistant cultivar is the best way to avoid many problems.
Learn more about the potential disease, insect, and animal pests, as well as the environmental conditions that can negatively affect roses and how to manage them below.
The first step in the successful culture of roses is correct planting. Roses can be purchased as container-grown or potted plants from the garden center or as bare-root plants from the garden center or mail-order source.
Roses should be planted in their ideal growing conditions. Roses perform best in well-drained soils in full sun. Sites should receive at least 6 hours of sun. In poorly drained areas, plant roses in raised beds. Learn more about the best growing conditions for roses in this article: Growing Roses in Iowa.
Below is more information on successfully planting and transplanting roses in your garden.
Most modern roses need protection to survive the cold winter months in Iowa. Hybrid tea, grandiflora, and floribunda, as well as some polyantha, miniature, and climbing roses, are not reliably winter hardy and must be protected.
Most shrub, landscape, species, and old garden roses, as well as some miniature, polyantha, and climbing roses, are reliably winter hardy and do not require extensive preparation for winter.
The process for preparing roses for winter is outlined below.
All roses benefit from pruning to improve their appearance and encourage better flowering. Pruning also helps reduce disease issues by increasing airflow and light penetration. In general, pruning is done in the early spring and starts by removing dead tissue from disease or winter kill. Then canes can be selectively removed to encourage vigorous growth and open up the plant to promote good air circulation and light penetration to reduce disease issues and improve bloom. Specific information on how to prune different types of roses is below.
Occasionally the need arises to move shrubs within the landscape. Follow the tips below to have the best success moving deciduous shrubs like lilac, viburnum, dogwood, ninebark, panicle hydrangea, and others.
When to Transplant
Early spring (before growth begins) and fall (after leaf drop) are the best times to transplant deciduous shrubs.
How to Transplant
Shrubs are best moved with a ball of soil adhering to the roots. With a portion of the root system intact, transplanting shock should be minimized with faster reestablishment.
The soil should be moist when the shrub is dug. If the soil is dry, thoroughly water the area 3 to 4 days before digging the plant.
There are several ways roses can be propagated. The best method depends on the type of rose and what is most comfortable for the gardener.
The most effective form of propagating roses for home gardens is by cuttings. Roses can also be propagated by layering, division, and seed. Each type of propagation has its advantages and disadvantages.
Cuttings | Layering | Division | Seed | More Information
For some shrubs, taking cuttings is not successful as propagules may die before new roots can be formed. In these cases, layering is another option.
Layering is a form of propagation where new roots are formed on vegetative pieces (primarily stems) while the propagule is still attached to the parent plant. This form of propagation produces propagules that are genetic clones so your propagule will be the exact same plant as the parent plant with the same flower color, form, and other attributes. This form of propagation can be time-consuming, but because plants are supported by the parent plant while developing new roots, it is relatively low stress on the plant and has a good rate of success for home gardeners.
Several factors cause branch dieback on trees. Correctly diagnosing the problem(s) is the first step in managing an unhealthy tree. Below are some common causes of branch dieback on trees in the landscape. Use this guide to evaluate your tree and determine the likely cause of the branch dieback.
Stem girdling roots happen when a tree’s own roots either completely encircle the trunk or grow tangential to the trunk on one or more sides, causing stem compression and damaging important vascular connections (xylem and phloem). Learn more about how to address this all too common issue with trees in the landscape.
https://hortnews.extension.iastate.edu/how-overwinter-roses-iowaRoses are grown by millions of gardeners throughout the world for their beautiful flowers. To reduce the confusion of selecting between thousands of rose varieties, roses are classified into various groups. In Iowa, the major groups of roses that can be grown include shrub roses, hybrid teas, miniatures, and others.
Each of these types varies in their season of bloom, winter hardiness, and maintenance requirements. Use the information below about each type of rose to select the best rose for your landscape.
Roses (Rosa sp.) are the quintessential garden plant. Their beautiful blooms come in many shades of pink, red, yellow, cream, white, and all the colors in between. Many are wonderfully fragrant and bloom from early summer to frost, forming colorful hips (fruit pods) in the fall. They make excellent cut flowers. The blooms make beautiful edible garnishes, can be dried for things like potpourri, and the hips are used to brew aromatic tea.
It's easy to see why we love roses. Learn more about the types of roses best suited for your garden and how to grow and care for them to keep them healthy and colorful all season.
There are about 300 species of geraniums. There is even a species of Geranium (Geranium maculatum) that is native to Iowa woodlands. Perennial or hardy geraniums are the “true geraniums” -- unlike the common “annual geraniums” (Pelargonium), which are often grown in outdoor containers. Perennial geraniums are also called cranesbills because their long, slender fruit resembles the beak or bill of a crane.
Deadheading is the removal of spent flowers. For many annuals, perennials, and roses, it is an important gardening chore. Deadheading improves the appearance of many plants, encourages the formation of additional blooms, and prevents the development of unwanted fruits or seed pods.
Coneflower is the common name of several genera of plants in the daisy family (Asteraceae) including Echinacea, Ratibida , and Rudbeckia. They make excellent garden plants and are native to North America, including several species in Iowa. In general, they grow in full sun, prefer dry to medium soils, and tolerate drought conditions well. Coneflowers often freely reseed in the garden. They are wonderful additions to pollinator gardens and are highly attractive to butterflies. Learn more about some of the coneflowers you can grow in your garden.
Peonies, daylilies, phlox and coneflowers are common perennials in home landscapes. Though not as widely planted as some perennials, Baptisias, or false indigos, are excellent plants for home gardens. The common name of false indigo refers to the fact that Baptisia australis and Baptisia tinctoria were used by Native Americans and European settlers to make a blue dye similar to that obtained from true indigo, Indigofera tinctoria. Baptisias are easy-to-grow, tough, long-lived perennials. They require little care and have no serious insect or disease pests.
Honey Bee Swarms are Common But Not Dangerous
Swarming is a natural process in the life of a honey bee colony. Swarming occurs when a large group of honey bees leaves an established colony and flies off to establish a new colony, essentially creating two from one. Swarming is a natural method of propagation that occurs in response to crowding within the colony. Swarming usually occurs in late spring and early summer and begins in the warmer hours of the day.
Annuals are indispensable additions to the home landscape because of their colorful flowers and long bloom period. Popular annuals for sunny sites include marigolds, petunias, and geraniums. Impatiens are the perfect choice for locations in partial shade.
Impatiens | New Guinea Impatiens | Rose Balsam | Growing from Seed | Impatiens Downy Mildew | More Information
Strawberries are one of the best fruits to grow in the home garden. When little garden space is available or there is not enough space in full sun to grow strawberries, containers are a fun alternative. When grown in a container, plants not only produce fruit but are also ornamental, making them an attractive addition to a patio or deck.
Growing strawberries in containers takes some special considerations. Learn more below about getting the most from container-grown strawberries.
This guide will help you schedule the planting of vegetable gardens so space may be used efficiently.
The range of dates provided are the time periods in which you could sow seed or plant transplant and have success. Some crops can be planted in succession (every 2 weeks for example) within that time frame. Other crops are simply planted at some point within that time frame.
The harvest dates are approximate based on planting on the earliest date listed and extending to the latest possible date. Crops that are not planted in succession will be harvested within that time frame, not for the entire time frame. Crops planted in succession could have sustainted harvest within that time period.
Dates listed are for Central Iowa. Southern Iowa can shift the sowing, planting, and harvesting dates approximately one week earlier. Northern Iowa can shift the dates approximately one week later.
Buckeyes and horsechestnuts are members of the genus Aesculus. The true chestnuts are members of a different genus - Castanea. Members of the genus Aesculus have palmate leaves – meaning they have 5-7 leaflets that fan out like fingers on your palm. They have showy flowers in spring, which mature to large dark brown capsules in late summer or early fall. While the hard, shiny buckeye fruits are considered good luck when carried in your pocket, they should not be eaten since they are poisonous to people.
With the arrival of spring, herbaceous perennials have popped up throughout the landscape! However, as you tour the garden in early spring you may notice that certain perennials are noticeably absent. Don’t worry. Several perennials are tardy every year. These perennials require several weeks of warm soils and air temperatures before they begin to grow in spring. Sometimes they do not emerge from the soil until June!
April showers truly bring May flowers. May is often the peak bloom time for spring-blooming plants in Iowa. While crabapple and lilac flowers often garner considerable attention in May, there are several perennials that produce an equally impressive display of spring blooms.
Overall, lilacs are easy to care for and problem-free shrubs. Occasionally, problems arise like failure to bloom, flowers opening out of season, powdery mildew, and other disease or insect issues.
More information about common lilac problems and how to manage them is presented below.
Lilacs offer gardeners a large variety of plant shapes, sizes, and flower colors. Hybridizers have worked extensively with the common lilac resulting in over 1000 different varieties. There are seven color classifications for lilacs: white, pink, violet, blue, magenta (reddish-purple), lilac, and purple. Flowers are also available in single and double forms.
Below are several species of lilac that grow in Iowa. They are roughly listed by bloom time from earliest to latest.