Care and How-To Articles - Ornamental Plants and Flowers

Spring Garden with Redbud in bloom

As winter fades and spring arrives, several things can be done to prepare the garden for the upcoming growing season.

Below are tips for the perennial garden, vegetable garden, annual containers, trees & shrubs, and lawns.

Manure is the oldest fertilizer known to civilization. Many gardeners feel manure is superior to synthetic products. Careful and appropriate use of manure, especially in vegetables gardens, is important. 

Petunias have been one of the most popular flowering annuals for years. Their popularity can be attributed to several desirable traits. Petunias are easy to grow, bloom reliably all summer, and are available in a wide range of colors, flower forms, and growth habits. 

Most gardeners buy petunias at their local garden center or greenhouse in spring. However, petunias can also be started indoors in late winter. 

Timing

Sow petunia seeds indoors about 10 weeks before the intended outdoor planting date. (Petunias should be planted outdoors after the danger of frost is past.) Late February or early March is an appropriate sowing date in Iowa. 

Impatiens are excellent plants for shady areas in the home landscape. Impatiens are ideal for flower beds, planters, and hanging baskets. Their versatility and adaptability to shade have made impatiens one of the most popular annual bedding plants in the United States. Impatiens are relatively easy to grow from seeds.

Timing

Impatiens are slow growing. Home gardeners should sow seeds in early to mid-February to produce stocky transplants by spring. 

Used plant containers

Reusing plastic, clay, and other containers is a great way to save money and reduce the amount of plastic waste that goes into landfill.  Plastic containers cannot be recycled in traditional single-stream home recycling programs and, unfortunately, programs to collect and recycle plastic pots are not common.

Proper cleaning and disinfecting of pots requires just a minimum amount of effort, yet can mean the difference between the success or failure of containerized plants, plus it allows you to reuse containers and reduce plastic waste. Follow the steps below to clean and disinfect used containers.

Blueberries Photo by Andris Tkachenko AdobeStock

Iowa soils are very diverse and so are the chemical characteristics that make up these soils.  Soil pH is one property that can vary widely across the state both naturally and due to how we manage the field or garden.  It is also one of the most cost effective and easy to manage soil properties that can be modified to improve plant health and crop production.


Steps to Decrease Soil pH  |  Steps to Increase Soil pH  |  More Information

Shrub Rose Carefree Beauty

Roses have been cultivated in gardens for centuries.  Gardeners have a long history of loving and growing this thorny perennial. Its sentimental appeal as a cut flower and in the garden has never wavered.

Roses in the Fossil Record

Our love of roses is rooted in several thousand years of admiration, cultivation, and hybridization. Fossil records show roses existed 30 million years ago in Europe, Asia, and North America. While these predecessors to today's Valentine's roses were less showy and floriferous, they were equally appreciated in many cultures through their long history.

geranium

Geraniums have been a popular bedding plant for many years.  Most gardeners purchase plants from garden centers and greenhouses.  However, geraniums can also be grown from seeds.  Se

red anthurium flower with yellow spadex (rod in middle)

Aroids or arums are members of the Araceae family.  The Araceae family is large, with more than 100 genera and 3700 species of mostly sub-tropical monocots.  Many species are popular as houseplants, and a few are distinctive landscape plants. 

cut flowers

Cut flowers are a welcome gift in any home, whether you receive a bouquet for Valentine's Day, a Birthday, Mother's Day, or you just decided to treat yourself to something beautiful.

When buying them from a florist, there are several things you can do to prolong the life of cut flowers. 

Spring, summer, and fall are a great time to bring the garden indoors with cut flowers.  No prior experience is necessary to harvest flowers for bouquets.   
If you cut flowers from your own garden, there are several things that can be done to condition those flowers to ensure they stay fresh, colorful, and vibrant for as long as possible.


Harvest & Conditioning  |  Care  |  Good Species from the Garden for Cut Flowers  |  More Information

Although herbs are commonly used for their medicinal and culinary uses, they can also be very ornamental. Ornamental perennial and annual herbs offer the added benefits of varying leaf color, texture, fragrance, and flowers. These multifunctional plants make wonderful additions to any garden from spring to fall.

cut flowers

Nearly every sentiment can be expressed by flowers. It’s been said that, “Flowers are a perfect replica of human life: Planting, growth, bloom, withering.”

The following list includes some of the most common flowers and their meanings, realizing there are multiple sources with this information and sometimes flowers can have multiple meanings.

Next time you give flowers to someone, consider selecting particular ones to express your sentiment.

Cut flowers

Valentine's Day is a day to recognize our loved ones.  Many different plants serve as wonderful gifts to show that special person how much you love them!  Cut flowers, orchids, and florist plants are just a few of the plants that are popular gifts on February 14th and the rest of the winter season.

Below are a few resources to help keep these special plants healthy and attractive all season.

Variety of Seeds

The late growing season is a good time to collect seeds from vegetables and flowers. Seed saving allows gardeners to preserve heirloom varieties or their favorite plants from year to year.  Below are the basics of harvesting, preparing, and storing seed from your garden.

Potted plants on a cart at the garden center

https://www.iowapbs.org/shows/gardeningsteil/digital-short/3531/plant-shoppingIn spring, many gardeners will be at nurseries, greenhouses, and garden centers looking to buy plants. Selecting the right species and cultivar of a plant for the landscape by matching sun, water, soil, winter hardiness, and other growing requirements is important. Equally important is selecting high-quality plants. Below is advice on how to purchase high-quality plants from the garden center.

storing seed in an air tight container

Storing Seeds

Proper storage conditions for seeds are essential to maintain viability and good germination at planting time. Seeds should be kept dry and cool.  A sealed glass jar can keep excess moisture out and protect seeds from pests like mice or insects. Store jars in a cool, dry location such as a cool closet, root cellar, or refrigerator. Test the germination rate on the seeds about one month prior to planting.

Sowing Seed in Plug Tray.  Photo by Adobe Stock

Mid-March is the best time to start many vegetables and annual flowers indoors for transplanting outside once the threat of frost has past. 

Regardless of what type of seed you're growing, to have the best success follow these basic tips:

  • Start with fresh seed and clean materials. 
  • Consult the package to determine how early to start the seed indoors - do not start seed too early. 
  • Provide abundant light. 
  • Do not over or under water.
  • Raise the humidity during germination.
  • If possible warm the germination mix/soil. 

More details about starting seeds indoors can be found below.

peat pots for seed starting

There are many different options for containers that can be used to start seedlings. 

sowing seeds photo by Adobe Stock

For many home gardeners, starting seeds indoors is great fun. Successfully growing seedlings indoors requires high-quality seeds, a germination medium, containers, lights, and other supplies.

sowing seeds photo by Adobe Stock

For many home gardeners, it's fun to get a head start on the upcoming garden season by starting seedlings indoors. Growing quality seedlings indoors requires high-quality seeds, a germination medium/potting mix, containers, proper temperature and moisture conditions, and adequate light.

Learn all of the steps to successfully start seeds indoors for your garden.

germinating seedling photo by adobestock

Germination requirements (light and temperature) vary among the different annuals and vegetables. The various crops also differ in the length of time from seed sowing until the seedlings are planted outdoors.  Below is germination and growing information for commonly grown annual flowers, herbs, and vegetables. 

Newly planted tree

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.


Trees & Shrubs | Perennials | Annuals | Bulbs | Lawns | Vegetables | More Information

Planting bulbs

There are several garden tasks to do when the garden season transitions from the heat of summer to the bright colors and crisp air of autumn.  The fall months are a great time to select and plant spring-flowering bulbs for next year. Spring-flowering bulbs offer reliable color and fragrance to the garden before many other plants wake from their long winter's nap. Gardeners can choose from traditional spring-flowering bulbs, such as daffodils, tulips, and hyacinths, or the unusual like squill, crown imperial, giant onion, or guinea-hen. A small investment of time and money in fall will reward you with beautiful flowers next spring.

Turf alternative

A lush green lawn is a goal for many homeowners, but getting a lush green carpet of turfgrass requires a lot of money and time spent on chemicals, mowing, watering, seeding, weeding, and other chores. While a well-maintained lawn provides a great space for recreation as well as a perfect backdrop for your home and garden beds, turfgrass is not the only option. Beautiful landscapes can also include a lawn created from many other plants that can provide a more interesting mix of color and textures as well as food and habitat for pollinators.  All of this while requiring fewer inputs!

Below are several alternative lawn options to consider.

picture of 'Fireworks' goldenrod at Reiman Gardens

Convincing some gardeners of the landscape value of goldenrods (Solidago species and hybrids) is not always easy. These plants have long suffered from an undeserved reputation as a common field weed that causes hay fever. In fact, ragweed is the primary hay fever culprit. Goldenrod is falsely accused because it flowers abundantly during the peak allergy season.

Growth Habit

Most goldenrods are clump-forming plants with erect to somewhat arching stems of varying heights and alternately arranged leaves. Flowers are typically yellow, but there are a few scarce white forms. Individual flowers are very small but are borne in great numbers to form flower heads of various shapes and sizes. Plants bloom over a long period in late summer and fall.

picture of lawn with clover

Pollinator Lawns, Bee Lawns, Freedom Lawns
All of these terms refer to the same idea - creating a lawn that is more friendly for insects.

picture of lambs ear

Groundcovers, by definition, are plants that spread. They are often low-growing perennials or shrubs that unify or define landscape beds and borders. Choosing the right groundcover for a landscape is important as they often consume large areas.  Groundcovers are also excellent choices where turfgrass is not desirable or practical.

There are also several species of groundcovers for shady sites (Groundcovers for Shade).  Some of the shade-loving species such as bugleweed and vinca perform equally as well in both shady and sunny sites. 

Picture of new garden bed being planted

The first step to creating any new garden bed in your lawn is to remove the existing sod.  There are several methods you can take to remove the turfgrass and each has its own advantages and limitations.  Which method you choose depends on the time it takes, the amount of work it requires, and your personal preferences. 
Use the guide below to determine which method of sod removal is best for your situation.

Picture of Dahlia

 Many summer-blooming tender perennials are great additions to the garden but are not winter hardy in Iowa.  These tender perennials must be dug up in the fall and stored indoors over winter.  This is possible because these plants grow from bulbs or other geophytes like corms or tubers. 

Taking a cutting

By the end of the growing season, many of our annual plants in the garden are gorgeous to overgrowing! It is hard to watch these prized flowers die after the first frost. Fortunately, some annuals can be propagated from cuttings and brought indoors during the winter. This is a great way to extend their beauty inside and reduce the cost of annual flowers for next spring.

Multiple perennial plants in containers partially buried in soil.

 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. 

Picture of heuchera with frost

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.

Fall Garden

When autumn arrives, several things can be done to prepare the garden for winter and the following growing season.


Perennials | Vegetable Garden | Annual Beds & Containers | Woody Trees & Shrubs | Lawns | More Information

Pink Flower of Swamp Milkweed

When selecting perennials, it’s important to choose plants that are suitable for the site.  Wet locations can be challenging, but they also provide gardening opportunities.  The following native perennials perform well in moist to wet soils in partial to full sun.  Possible planting sites include water gardens, rain gardens, pond banks, landscape beds, and naturalized areas. 

A newly planted maple tree showing signs of drought stress

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.

Fern in shade garden

Ferns are great additions to the Iowa shade garden.  They are often found in shaded, damp forests in both temperate and tropical areas of the world, but many have adapted themselves to survive in a variety of environments. The ferns that will grow in Iowa range in size from less than 1 foot tall to more than 3 feet tall.  Ferns can be used as focal points, or as background or filler plants in shady garden beds.

Bee balm with nectar-feeding bumble bee.

In July and August, the attractive flowers of bee balm (Monarda) are a common sight in gardens, along roadsides, and in prairies.  Bee balm attracts bees, butterflies, and hummingbirds.  The common name of bee balm is in reference to its former use to treat bee stings.  Other common names include bergamot, horsemint, and Oswego tea.  When sited properly and given good care, bee balm is a wonderful, easy-to-grow perennial for the home landscape.

Description

Three species of Monarda (Monarda didymaMonarda fistulosa, and Monarda punctata) are native to Iowa.  Numerous cultivated varieties are available at garden centers.

Photo of violet Phlox paniculata

There are many perennials that bloom reliably every summer. Phlox represent some of the most reliable perennials to grow in Iowa.  There are over 60 phlox species native to North America. While many of these species are suitable for Midwestern gardens, below are a few species that are the most popular for Iowa Landscapes. 

Picture of groundcovers in shade

Attempting to grow grass under large shade trees or shady areas created by buildings, fences, and walls is difficult and frustrating.  Because of unfavorable growing conditions, grass doesn’t grow well in shady areas and the area is often little more than bare soil and a few weeds.  A shade-tolerant groundcover is an excellent alternative to turfgrass in shady areas. Once they are established, groundcovers require less maintenance than turf, they can out-compete most weeds, and some have attractive flowers as well. Groundcovers will require more time to establish initially but are worth the effort in the long run.

Photo of thin grass in shade of maple tree

Trees provide many benefits but unfortunately, trees and turfgrass are not very compatible. Large trees cast considerable shade. Trees also compete with turfgrass for water and nutrients. As a result, most turfgrasses have a difficult time growing in the vicinity of large shade trees.

If the grass growing in shady spaces is not looking good, you have a few options to improve the appearance of these areas in your landscape. You can remove the turfgrass and plant an alternative species that will tolerate the shady conditions better.  You can also remove the turfgrass and lay down mulch.  Finally, if you want to have turfgrass growing in the area you have to change the way you maintain and care for the turfgrass to get it to grow more successfully

Each of these options has its advantages and challenges.  Consider each to determine which will work best for your landscape.

iris in bloom

There are over 200 species of Iris.  Most irises grow from thick, underground stems or rhizomes.  A few species are bulbous.  An iris flower typically consists of 6 segments.  The 3 inner segments, which are generally upright, are referred to as standards.  The drooping, outer 3 segments are known as falls. 

Bearded irises are one of the most popular and widely grown perennials in the home landscape.  Though not as widely grown, several other types or species of iris are also attractive additions to the perennial garden.  By selecting and planting several different iris species, gardeners can enjoy blooming irises from April through July.  

watering annuals in a container

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.

honeyvine

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.

mulch over newspaper

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.

Ground ivy in bloom covering a yard

Ground ivy (Glechoma hederacea), also known as creeping charlie, is a common weed in many lawns.  Ground ivy is a low-growing, creeping, invasive perennial.  It spreads by seed and the vining stems (stolons) which root at their nodes.  The leaves of ground ivy are round or kidney-shaped with scalloped margins.  Stems are four-sided.  Flowers are small, bluish purple, and funnel-shaped.  Ground ivy thrives in damp, shady areas, but also grows well in sunny locations.  A member of the mint family, ground ivy produces a minty odor when cut or crushed. 

Management Options for Ground Ivy in Lawns | Management Options for Ground Ivy in Garden Beds

Peony Flower

Peonies can be left undisturbed in the garden for many years. Occasionally, however, it becomes necessary to move plants. 

Learn all about the when and how of transplanting and dividing peonies.

Seedlings being hardened off. Photo by Adobe Stock

Each spring home gardeners buy bedding plants (annual flowers and vegetables) from local garden centers and greenhouses. To help ensure a successful start to the gardening season, select strong, healthy plants and harden them outdoors for a few days before planting. Proper planting is another key to success.

Selection

Select short, stocky plants with dark green foliage. Avoid tall, spindly plants. Smaller seedlings become established in the garden more quickly than larger ones. Also, smaller plants are often more productive. When selecting bedding plants, "large" is usually not better.

Climbing hydrangea on a building around a window

Vines add interest to all gardens. They offer a wide variety of leaf forms, textures, and colors as well as attractive flowers or fruit. Perennial vines do not need replanting every year and can be used as a screen and to provide shade, fragrance, or fruit. They are often incorporated into gardens along walls, fences, trellises, arbors, or in containers to add height quickly in a limited space.

Learn about the vines you can grow in your Iowa landscape.