Care and How-To Articles - Problems and Pests

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

healthy oak leaves

Oak trees are valuable assets in the home landscape.  Occasionally oak trees need to be pruned for health, safety, and appearance reasons.  Pruning oaks makes them more valuable to infection from the fungus that causes oak wilt. By pruning oaks properly, you can reduce that risk and keep trees healthy.

poison ivy

Poison ivy (Toxicodendron radicans) is a native vine common to woodland areas but found frequently growing in gardens and along fence lines.  This vine causes an allergic reaction (dermatitis) in most people when their skin comes in contact with urushiol produced by the plant and present in all parts of the plant including leaves, stems, and roots on both living and dead plant material. 

Control of this weedy vine requires special consideration.  When working around this plant, gardeners should wear long sleeves and pants with waterproof gloves to protect the skin from the urushiol oil. 

Perennial grassy weeds die back to ground level in the fall but send up new growth from the same root system in the spring.  These weed species have long thin leaves with parallel veins.  They are often in the Poaceae (grass) family or a closely related family and are botanically classified as monocots.  Perennial weeds reproduce by seeds or may spread by creeping above or below ground stems or by spreading root systems. Examples of perennial grassy weeds include quackgrass, nimblewill, orchard grass, and in certain cases bermudagrass and zoysiagrass.

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. 


Perennial broadleaf weeds die back to ground level in fall but send up new growth in spring.  These weed species have leaves that are wider and often have a major vein running down the center of the leaf with secondary veins branching off of it.  They are typically botanically classified as eudicots (dicots).  Perennial weeds reproduce by seeds or may spread by creeping above or below ground stems or by spreading root systems. Examples of perennial broadleaf weeds include dandelion, thistle, pokeweed, plantain, violet, and creeping Charlie.


Annual weeds grow rapidly, flower, set seed and die in a single season. New annual weeds, such as crabgrass, velvetleaf, purslane, knotweed, lambsquarter and foxtail, germinate from seeds each year. Before they die, most annual weeds produce large quantities of seeds. If annual weeds are controlled every year before producing seeds, they will eventually become less of a problem as the seed population gradually decreases. 

Annual weeds like crabgrass (Digitaria sanguinalis​​​​​) grow from seed each year.

Flame weeding is the use of intense heat, usually produced by a propane torch or other fuel-burning device, to kill weeds.  This organic option for weeding causes the water and sap inside the plant cell to boil and expand rupturing the cell walls and causing the plant to wilt and die.  

Flame Weeding is Not Setting Plants on Fire!

The goal is not to ignite the weeds on fire.  Instead, plants are subjected to a brief, intense heat that causes the cell walls to burst.  Immediately after exposure plants will turn a dull green and wilt slightly.  Over the next several hours to days weeds will wilt completely and die.  

Managing weeds in the vegetable garden is important for growing healthy and productive plants.  There are several methods that can be used to manage weeds and in most cases using several methods together will produce the best results.  All of these methods can be considered "organic" except those that utilize herbicides.  

A variety of indoor plants

Due to improved construction methods, buildings are better sealed to maximize energy efficiency. Yet, these "sealed" buildings often trap gases from synthetic materials that can pollute the indoor air. These air pollutants can cause problems for inhabitants especially during the winter when people are forced to spend a great deal of time indoors.

ice covered magnolia

Heavy amounts of snow and ice on the branches of trees and shrubs can cause considerable damage. Improper removal of ice and snow can increase the amount of damage to trees and shrubs. Learn about how to manage ice and heavy snow on trees and shrubs.

Salt and Sand Deicing Material on Patio

Snow and ice are headaches for motorists and pedestrians. To prevent accidents on slippery surfaces, deicing compounds are used by highway departments, businesses, and homeowners to melt ice and snow on roadways, parking lots, sidewalks, and driveways. While deicing materials improve travel conditions, they can damage automobiles, concrete surfaces, and landscape plants. 

Learn about the important considerations that must be taken for using deicing materials in your landscape.

Rabbit feeding injury to crabapple tree

Deer, rabbits, mice, voles, and other animals can cause a lot of damage on trees and shrubs over the winter months.  Prevention is key to managing these garden pests.  By taking steps in the fall, you can prevent damage from occurring over the winter.

Common Morel, Morchella americana

Identifying mushrooms can be challenging when compared to identifying trees, birds, or butterflies. Challenges of identification stem from the lack of information collected in the field or lack of distinguishing features on the mushrooms collected. Fungi guides often rely on details that may be easily overlooked in the field or require microscope observations.  But don’t let these challenges stop you from trying to identify that mushroom.

Raccoon Damage to Lawn

In late summer and fall, skunks and raccoons can cause damage to lawns as they search for earthworms, soil-dwelling insects, and insect larvae, such as white grubs.  They dig up the lawn leaving behind large patches of loose turf, eat the grubs, worms, or other insects and leave behind a torn-up mess.  The damage can be extensive and often happens overnight as both skunks and raccoons are active and feed at night. 

Hail damage on young apple fruit. Picture credit: Jose Gonzales-Acuna

While there are many environmental factors that can damage apple trees as well as the apple fruit, hail damage is one that can be very frustrating. Below are answers to questions that come up quite frequently regarding hail damage on apples.

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.

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.

red apples on the apple tree

Growing high-quality apples in the home garden is possible but requires significant inputs. Apples have several serious disease and insect pests that can significantly lower the quantity and quality of the apple harvest in the fall. Managing these disease and insect pests is important, and many of the most effective management steps occur in spring, well before the apples form and ripen.

Hosta with Deer Damage

Damage caused by deer browsing on garden plants can be a problem in rural and suburban areas in Iowa. The amount of damage depends upon seasonal factors, weather conditions, availability of alternative foods, and plant palatability. Prevention of deer browsing is difficult.  

Browse these lists of plants that are less likely to browsed by deer.

Rabbits can cause extensive damage to flowers and vegetables in the home garden. Fortunately, some plants are usually ignored by browsing rabbits. No plant is guaranteed to not be browsed on by rabbits, but they tend to avoid plants with strong aromas or dense hairy leaves.  The feeding habits of rabbits may vary due to fluctuations in the rabbit population, availability of alternate foods, and other factors.

The most effective way to prevent damage from rabbit browsing is to exclude them from the garden.  More information about rabbit management can be found at this website: Rabbits: Damage Management

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.

Wild parsnip in flower

Wild parsnip, Pastinaca sativa, is a common roadside weed in Iowa. Wild parsnip is a non-native plant in the parsnip family that originated in Europe. The edible roots were consumed in ancient Greece and Rome and there are still some cultivars grown for food today. Wild parsnip also poses a health hazard that many people may not be aware of.

Identification  |  Distribution  |  How it's Hazardous to Human Health  |  Control Measures

Colorado potato beetle (adult).

One of the familiar pests of the garden is the Colorado potato beetle, also known as the "potatobug." It's interesting to note that potatobugs were very familiar to Iowans through the first half of the 20th century but that they seemed to disappear for a while only to re-emerge as a major pest problem in the 1990s and remain widespread and destructive to this day.  Colorado potato beetles feed on the foliage of potato, tomato, eggplant, pepper and other related plants. They are most damaging to potatoes where the defoliation reduces yields and may even kill plants.


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.  They are perennial and typically classified as eudicots, although some may belong to other plant groups like gymnosperms (conifers).  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. 

Pulling & Digging  |  Mowing  |  Herbicides

Suckers at the base of a crabapple tree

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.

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

brown patches from warm season grass

In spring, the cool-season lawns common across much of Iowa turn a vibrant green.  Occasionally, you will notice large "dead" patches of grass. Often the brown patch of grass seems to get larger every year. Upon closer inspection of the grass, one can see that there are no spots on the blades (from fungal fruiting bodies) or darkening of the roots or crowns (the part of the plant at the soil line).  These brown spots are typically caused by a couple of different environmental issues.

Bumpy, rough, uneven lawns are annoying, difficult to mow, and potentially dangerous. Several factors contribute to bumpy lawns.

Factors That Contribute to Bumpy Lawns

Many older, established lawns become rough and uneven over time as the turfgrass gradually thins. Sparse, thin lawns have less foliar growth and cushioning effect than thick, dense turfgrass. Thin lawns may be caused by poor maintenance, shade, insects, diseases, and other factors. The reestablishment of a healthy, thick turf would help to alleviate this problem. Bluegrass is generally the best grass for sunny areas, while the fine leaf fescues tolerate considerable shade. Tall fescue is also shade tolerant.

Newly planted sycamore tree under stress

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.

Frost Damage on Ginkgo

Unseasonably warm weather in late March and early April can encourage many trees and shrubs to leaf out earlier than normal. Newly emerged growth is quite succulent and susceptible to damage from strong winds and below freezing temperatures. 

Learn how to identify freeze damage on trees and shrubs and what you can do to manage it.

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.

Winter Browning of Conifers  |  Sunscald Injury  |  Animal Damage

Wilted Peace Lily

Growing indoors plants is a rewarding hobby that yields beautiful results.  But when problems arise with your indoor plants, it can be difficult to determine what to do to fix the problem.  Learn what to do when your houseplants have problems.