Ants aren’t necessary for peonies to flower. The ants are attracted to the sugary nectar produced by the peony buds. The nectar is a good food source for the ants. Peony buds will open without the presence of ants.
Learn more about growing peonies in Iowa in this article: Growing Peonies in Iowa
In addition to their landscape uses, daylily leaves and flowers are edible. Edible materials should be gathered from only those plants that have not been sprayed with any pesticides.
Three-to five-inch-long young foliage can be simmered or stir-fried (older foliage tends to be stringy and tough).
Flower buds and blossoms can also be eaten at any stage of growth. The tight buds can be used in salads, boiled, pickled or stir-fried. All stages of bloom, from half-open to day-old, can be eaten deep-fried with a light batter. Petals can be eaten raw right off the plant and have a buttered lettuce flavor.
Since daylilies can act as a diuretic, it's best to eat them in moderation.
Louisiana iris is the collective name for several species of iris which are native to Louisiana and boggy coastal areas from Florida to Texas. They are prized for their colorful white, blue, red, or yellow flowers. Louisiana irises are excellent plants for water or bog gardens.
While Louisiana irises are native to the Gulf coast states, they are remarkably hardy. They can be successfully grown in USDA Hardiness Zones 4 to 9. Louisiana irises prefer moist, neutral to acid soils in partial shade to full sun. Protected planting sites are best. Water plants weekly during dry periods. To insure winter survival in Zone 4, cover Louisiana irises with several inches of straw in late fall.
Most iris species (bearded, Siberian, Japanese, etc.) perform best when grown in partial to full sun. However, the crested iris (Iris cristata) prefers partial shade. A native of the eastern United States, crested iris produces 4- to 6-inch-long leaves from woody, spindle-shaped rhizomes. Flowers are pale blue to violet with white or yellow crests on their falls. Plants bloom in mid-spring. It is hardy in USDA Hardiness Zones 3 to 8. Because of its small size, crested iris should be grown in the front of perennial beds and borders. It can also be grown as a groundcover in partial shade.
While they are both called "soaps," dish soap (like Dawn or Palmolive) is not a replacement for insecticidal soap.
Dish soap is actually more accurately classified as a detergent, not a soap. Soap is a molecule composed of salts (such as potassium or sodium) and fatty acids. Detergents are derived from petrochemicals and are a different type of molecule.
While dish soaps (detergents) can cause issues for insects, their effect on pests is limited and highly variable. Dish soap is also much more likely to cause damage to the plant, such as phytotoxicity. Insecticidal soap is a true soap (usually potassium salts of fatty acids) created specifically to target pests. They work on contact by damaging the insect's cell membranes. The cell contents are able to leak from the damaged cells, and the insect dies. They have no residual action and easily wash away. This is what makes insecticidal soaps a safer pesticide option compared to traditional pesticides. This also means, however, that insecticidal soaps have to be applied frequently to control insect populations as they only affect the insects they come in contact with. Any hiding insects or those that emerge after the application would be unaffected and would require a second (or third, etc.) application to kill them.
True lupines (Lupinus species), such as the Russell hybrids, are grown for their attractive, erect, 1- to 2-foot-long flower stalks. Unfortunately, the Russell hybrids and most other lupines don’t perform well in Iowa. Lupines prefer moist, well-drained soils and cool temperatures. Because of our hot, dry summers, lupines tend to be short-lived perennials in the state.
While true lupines are difficult to grow in Iowa, the Carolina lupine (Thermopsis villosa) and false blue indigo (Baptisia australis) are well adapted to the state and produce colorful, lupine-like flower stalks. The Carolina lupine produces bright yellow, pea-like flowers on erect, 6- to 12-inch-long flower stalks in late spring. Plants have gray-green to green foliage and grow 3 to 4 feet tall. False blue indigo produces indigo blue flowers on 8- to 12-inch-long flower stalks in spring. Plants grow 3 to 5 feet tall with a spread of 4 or more feet. Its foliage is blue-green.
Some perennials, such as garden peonies, can be left undisturbed for 50 or more years.
Others need to be divided periodically to contain their spread or to rejuvenate declining plants. Vigorous growing perennials include:
They grow so rapidly that they begin to crowd out neighboring plants within a few years. Gooseneck loosestrife and other vigorous growers should be divided every 2 to 3 years. After dividing the perennials, replant some of the divisions, give others to relatives or neighbors, and discard remaining plants in the compost pile.
In contrast, the performance of some perennials, such as bearded iris (Iris hybrids), begins to decline after several years. If not divided every 3 to 5 years, bearded irises usually don’t bloom well because of overcrowding. Declining perennials should be divided to rejuvenate the plants.
Learn more in this article: How to Divide and Transplant Perennials.
There are several possible explanations why peony buds fail to open.
Peonies bloom best in full sun. In partial to heavy shade, plants are weak and may not be able to supply adequate food to the developing buds. As a result, the undernourished buds don’t develop fully. Peonies growing in partial to heavy shade should be transplanted to a sunny site in September.
Fungal diseases, such as Botrytis blight, may infect peony buds. Infected buds turn brownish black and wither. Fungal diseases are most common during cool, wet, spring weather. Sanitation is the most effective means of controlling Botrytis blight and other peony diseases. Cut off peony foliage at ground level in fall. Remove the diseased plant debris from the area and destroy it.
The flower buds may have been damaged by a late freeze. While the plants themselves can tolerate a light freeze, the buds are more susceptible to cold injury. Unfortunately, little can be done to avoid this problem.
Learn more about growing peonies in Iowa in this article: Growing Peonies in Iowa
Peony flowers are harvested for cut flowers when they are in bud, before they open. Flower buds that are showing color and are soft in the center are at the best stage to harvest for cut flowers. After harvest, flowers can be placed immediately into vases of warm water for bouquets or they can be stored in a refrigerator for later use. Flower stems that are stored in a refrigerator should be leafless and wrapped tightly in moist paper or clear plastic to keep them supple until needed. Moist refrigeration allows you to keep peony flower buds fresh for several weeks. When ready for bouquets, simply remove them from refrigeration, recut the stems, and place in warm water to initiate flower opening.
Learn more about growing peonies in Iowa in this article: Growing Peonies in Iowa
All perennials require some maintenance. Watering, fertilizing, pinching, staking, deadheading, dividing, and providing winter protection are common maintenance chores. Some perennials require frequent attention through the growing season. Others require minimal care.
Many peony flowers have double or triple the number of petals – making them too heavy for their stems to support. Therefore, staking the peony stems as they emerge in the spring or as the flower buds are forming will provide the extra support needed to keep the blooms upright.
Learn more about growing peonies in Iowa in this article: Growing Peonies in Iowa
Chrysanthemums can be propagated by division and cuttings.
Divide mums in early spring just as new growth begins to appear. Dig up the entire plant and divide each plant clump into sections with a sharp knife. Each division should contain several shoots and a portion of the root system. Immediately replant the divisions.
Collect cutting material in spring or early summer. When the shoots are several inches tall, cut off the upper 3 to 4 inches with a sharp knife. Pinch off the leaves on the lower portion of the cuttings. Dip the bottom of the cuttings in a rooting hormone. Then stick the cuttings in a rooting medium of coarse sand or perlite. Keep the rooting medium moist. The cuttings should root in 4 to 5 weeks. When the cuttings have good root systems, remove them from the rooting medium and transplant the rooted cuttings into pots or plant directly into the garden.
Learn more in this article: Growing Chrysanthemums in Iowa.
Symptoms of herbicide damage vary and depend on the type, formulation, concentration, mode of action, source, and amount of herbicide, as well as the plant species affected, application method, equipment used, and weather conditions during and after application.
Symptoms of herbicide injury are varied but, in general, include:
Herbicide injury typically affects all or most plants in an area, regardless of species. For example, distorted, weak growth with leaf yellowing is observed on tomatoes, beans, broccoli, and peppers in the same garden area. Or tomatoes, peppers, and beans at one end of the garden all show symptoms, and the same species at the other end (further from the herbicide application) do not.
Depending on the active ingredient, symptoms may only be on certain types of plants. For example, all the broadleaf plants in the area show symptoms, but none of the grassy plants have issues. While herbicide damage can cause similar symptoms across multiple species in the same area, insect or disease issues rarely affect unrelated plant species in the same way.
Some plant species are more sensitive to certain types or formulations of herbicides than others. For example, plants like tomato, grape, pepper, apple, maple, peach, strawberry, elm, redbud, geranium, petunia, and coleus show much more sensitivity to off-target applications of 2,4-D or Dicamba than plants like hosta, daylily, zinnia, marigold, and vinca.
Sensitive species will show more extensive damage than non-sensitive species. More sensitive plant species are also more likely to show damage at greater distances from the herbicide application than less sensitive species.
Herbicide injury symptoms may develop within a few hours, a few days, or more than a week after the application, depending on the product used.
Herbicide residue or carryover in mulch, manure, compost, and soil can cause injury symptoms in the days or weeks following the application of the soil or amendment.
If you know a herbicide application was made in the area prior to the appearance of symptoms, that can further confirm herbicide injury as the cause of the issues. Remember, just because a herbicide was applied nearby does not mean the symptoms observed are caused by herbicide drift or misapplication. But when symptoms or patterns indicate herbicide injury, and it's known that an application was made nearby, it can help further confirm the cause of the issue.
Learn more in this article: Herbicide Injury to Garden Plants.
When planting bearded irises, dig a hole large enough to accommodate the rhizome and roots. Build a mound in the center of the hole. Place the rhizome on top of the mound and spread the roots in the surrounding trench. Then cover with soil. When planted, the rhizome should be just below the soil surface.
Ornamental grasses are low-maintenance perennials. Most thrive in sunny sites and there are species that can grow in dry, well-drained, or wet soils. While small in the nursery, many can get quite large in just a couple of years, so check the labels carefully for mature size and site preferences. Once established, grasses need minimal care requiring watering only in times of drought. Ornamental grasses rarely need fertilizer. If growth is pale, weak, or floppy, scatter some granular fertilizer around them in the spring.
Let grasses and their ornamental flower heads stand all winter. Even when tan and dead, they are quite attractive after a snowfall. Cut back ornamental grasses in early spring before the new growth appears. Division is sometimes necessary to keep ornamental grasses thriving in the landscape. If the center of the clump begins to thin or die out, divide in early spring just as the new growth appears.
Learn more in this article: Ornamental Grasses for the Home Landscape.
Crabgrass is an annual weed. In flower and vegetable gardens, hoeing and hand pulling are the best control options. When cultivating the garden, avoid deep tillage. The roots of many vegetables and flowers grow near the soil surface. Deep cultivation will cut off some of these roots. Also, deep cultivation will bring deeply buried weed seeds to the soil surface where they can germinate. Hand pulling is best done after a good rain.
Learn more in this article: How to Control Crabgrass.
Annual grasses, such as crabgrass and foxtail, can be controlled by hand pulling.
Perennial grasses, such as quackgrass, are much more difficult to control as they spread via underground stems or rhizomes. (All of the rhizomes must be completely destroyed to control quackgrass.)
When confronted with an iris bed infested with quackgrass, one option is to dig up the irises in July or August and replant them in a different (weed-free) location. Another option is to dig up the irises in July or August, set the irises in a shady location, and then dig up the grass and carefully remove the rhizomes and other plant parts. Dig up the area 2 or 3 times over a 3 to 4 week period, each time removing any rhizomes visible in the soil. Replant the irises in their original location after thorough eradication efforts. Quackgrass cannot be controlled by hand pulling. Herbicides are not a practical control measure for home gardeners.
Knowing the area of the garden bed or lawn is necessary for applying fertilizers or pesticides, determining how much mulch is needed, or determining the number of plants needed to fill a space.
The method for determining the area of your lawn or garden depends on the shape. Use the information below to find the area of your garden bed or lawn.
Rectangle | Triangle | Circle | Semicircle | Oval | Irregular-Shaped
A simple rectangular bed is one of the most straightforward bed shapes to determine the area. Simply, multiply its length by its width.
Area = length × width
To determine the area of a triangular-shaped planting bed, measure the length of the base and then the height (the distance from the top point down to the base). Then, use the formula below to determine square footage.
Area = base × height × 0.5
For a round planting bed, multiply pi (π=3.14) by the radius squared. The radius equals the distance from the center of the circle to the edge.
Area = 3.14 × radius2
For a semicircle (also called a half-moon or half-circle) bed, start by finding the length of the radius. For a semicircle, the radius equals the length of the flat/straight edge divided by two. Then, use the formula for the area of a circle and multiply it by one-half.
Area = 3.14 × radius2 × 0.5
An oval bed (more accurately referred to as an ellipse) can be found after collecting two measurements. Measure from the center of the bed to the furthest edge point. This is called the major radius. Then, going back to the center, at a right angle to the major radius, measure from the center to the bed edge - this is the minor radius. Multiply those two numbers by pi (π=3.14) to get the area.
Area = 3.14 × major radius × minor radius
Many garden beds have a more irregular shape. For beds comprising straight lines, simply break the bed apart into triangles, rectangles, and/or semicircles. Find the area of each piece and add them together.
For more complex irregular shapes, such as a bed shaped like a kidney bean, the bed area can be estimated with decent accuracy by first gathering several measurements. Find the length of the longest line within the shape - this is the length line. Along this length line, measure perpendicular width lines (at a 90° angle) to the length line. The distance between the width lines (called the segment width) must be equal. For example, you might measure the width of the bed every 3 feet along that length line. You can measure any number of width lines as long as they are equidistant from each other. The more width lines you measure, the more precise your area calculation will be. To find the area, add all of the width line lengths together and multiply that by the segment width.
Area = (sum of all width lines) × segment width
As soon as bearded irises are done blooming, remove the spent flowers. Removal of the spent flowers improves the appearance of the plants and prevents seed pod formation. Bearded irises require little care during the summer months. In late fall or early spring, remove the dead iris foliage. This helps to control leaf spot and iris borer. To prevent overcrowding, bearded irises should be divided every 3 to 5 years in July or August.
Pinch chrysanthemums 2 to 3 times from spring to mid-summer. Remove the stem tips when the shoots are 6 to 8 inches tall. New lateral shoots will develop along the stems. Pinch again when these new shoots reach a length of 6 to 8 inches. Pinching can be done with your fingers or a pair of hedge clippers. Continue pinching until early July. Pinching results in bushy, compact plants with additional flowers.
Learn more in this article: Growing Chrysanthemums in Iowa.
Bee balms like an even supply of moisture during the growing season. For best performance, water bee balms every 7 to 10 days during dry periods. When watering, soak the soil to a depth of 6 to 8 inches. Apply a mulch around plants to conserve soil moisture and reduce the frequency of watering.
Astilbes perform best in moist, well-drained soils in partial shade. Plants like evenly moist soils throughout the growing season. Astilbes do not like dry sites. Their foliage will turn brown when plants don’t have adequate moisture. Water retention in soils that dry quickly can be improved by working organic matter, such as compost or peat, into the soil before planting. After planting, place a 2-inch-layer of mulch around plants to conserve soil moisture. Watering will probably be necessary during prolonged dry periods. Astilbes prefer partially shaded sites that receive 2 to 4 hours of sun per day.
Don’t worry. The balloon flower (Platycodon grandiflorus) is slow to emerge in spring. Other late emerging perennials include hardy hibiscus (Hibiscus hybrids), butterfly weed (Asclepias tuberosa), and Russian sage (Perovskia atriplicifolia). It’s a good practice to mark the locations of late emerging perennials to prevent damaging these plants when working in the garden in early spring.
Learn more in this article: Late-Emerging Perennials: Some Species Just Get a Late Start to Spring!
Bearded irises should be divided every three to five years. If not divided, plants become overcrowded and flower production decreases. July or August is the best time to dig, divide, and transplant bearded irises.
If bearded iris is planted too deeply, plants will have poor bloom. Bearded irises grow from thick, underground stems called rhizomes. When planted, the rhizome should be at or just below the soil surface. In many cases, the top of the rhizome can be visible at the soil surface. Occasionally over time a build-up of soil, mulch, or other organic material will place the large fleshy rhizomes too deep underground. Dig and reset the rhizomes to the proper depth in mid-summer.
Lack of sunlight could be another possible reason for a lack of flowers. Bearded irises bloom best in full sun. Plants need at least six hours of direct sun per day for best flowering. It is possible for established bearded iris plants to be planted in full sun but then become shaded over time when trees and shrubs around them get larger. Plants in partial shade may not bloom well and should be transplanted to a sunny site.
There are several factors which may cause peonies to bloom poorly. Peonies perform best in areas that receive at least 6 hours of direct sun each day. Peonies that receive less than 4 hours of direct sun will not bloom well. Plants growing in a shady location should be transplanted to sunny site in September. Peonies planted too deeply often fail to bloom well. When planting peonies, position the peony buds 1 to 2 inches below the soil surface. Peonies that are planted too deeply produce lush foliage, but don’t bloom well. Recently planted or divided peonies may not bloom well for 2 or 3 years. The new plants need to grow stronger before they are capable of blooming well. Also, premature removal of peony foliage in July or August weakens plants, resulting in few flowers the following spring.
Excellent groundcovers for shade include:
Variegated bishop’s weed (Aegopodium podagraria ‘Variegata’) and lily-of-the-valley (Convallaria majalis) are two other shade-tolerant groundcovers. Unfortunately, both plants spread rapidly and often become invasive. These aggressive spreaders should not be planted with other perennials as they quickly crowd out neighboring plants. Variegated bishop’s weed and lily-of-the-valley should be planted only in areas where they can be confined (for example, between a building and sidewalk) or allowed to spread freely.
Learn more in this article: Groundcovers for Shade.
Plant heights vary somewhat based on the growing conditions at the site. However, there are several groundcovers that are 12 inches or less in height.
Low-growing groundcovers for shade include:
Excellent low-growing groundcovers for sunny areas contain:
Many of the best perennials for full sun are native to the prairie. Some Iowa native prairie plants that make good additions to the home landscape include:
When selecting plants for the shade garden, one group of plants that is often overlooked are native woodland wildflowers. Since they are native to the state, woodland wildflowers are well adapted to the area. They are easy to grow and perform well when given a favorable environment.
Native woodland wildflowers that make good additions to the home landscape include:
Obtaining plants is easy. Woodland wildflowers are readily available at garden centers and mail-order nurseries. Do not remove plants from natural woodland areas.
Learn more in this article: Native Woodland Flowers for the Home Garden
Dozens of native prairie and woodland perennials are wonderful ornamental additions to the landscape. These plants are all native to the state of Iowa. The list includes plants that grow in a wide variety of conditions, from sun to shade and wet to dry soil conditions.
