Champaign County Master Gardener and Horticulture Program

05/27/2026

There are different kinds of mulches:
--Living: ground covers, cover crops
--Synthetic: such as recycled pieces of rubber, landscape fabric, sheets of black plastic
--Inorganic: stone, concrete, bricks
--Organic: cardboard, newspaper, compost, sawdust, nutshells, wood chips

According to a published* review of research articles on the topic, the overwhelming choice for most beneficial landscape mulch is arborist wood chip mulch. This kind of mulch provides many more benefits than drawbacks than the other choices. The benefit of any kind of mulch is to: reduce the loss of moisture from the soil, reduce soil erosion, moderate soil temperature and reduce w**ds. Some kinds, though, can actually damage soil and plants or do as much harm as good. Living mulches can compete with the desired plants for water, nutrients and space. Synthetic mulches can contaminate the soil as they decompose or reduce the movement of water and air between the soil and the atmosphere; landscape fabric reduces the movement of gasses by a factor of 100 compared to 4” of arborist wood mulch! This movement is necessary for plant and soil health. While inorganic mulches don’t have to be replaced frequently, they can also be less effective as methods of reducing w**ds. W**d seeds and soil can blow in on top of stones, leading to the growth of w**ds that are difficult to control.

Wood chip mulch can be applied in a deep enough layer (4”) to restrict w**d growth without reducing the exchange of air and water. Wood mulches also support beneficial microbes that support soil and plant health. Arborist wood chip mulches—as the name says—are available from tree services that run clippings, limbs and trunks through the chipper. Some homeowners and landscape professionals have been reluctant to use these because of some misconceptions about wood mulch: 1. According to this article, wood chip mulch which is acidic will not change the pH of the soil—the sheer volume of the soil in a yard or landscape offsets any possible change. 2. Coarsely chopped wood chips won’t injure plants or spread disease even if they come from diseased trees. 3.Some finely textured, shredded wood mulch can form an impermeable mat, restricting air and water flow. A homeowner can offset this by breaking up the mat during a season with a heavy rake or other implement. 4. One myth is that woody mulches attract pests, but the decomposition process increases microbial growth that overcomes harmful pathogens. W**d seeds are inhibited from growing due to the lack of light in lower layers of deep mulch.

A study reported in the American Society for Horticultural Science journal (https://journals.ashs.org/view/journals/hortsci/44/5/article-p1419.xml) confirms the benefits of mulching, noting that it increases soil moisture retention by reducing evaporation and competition from w**ds for that moisture. A nine-year study compared the growth and health of shrubs in similar plots that were mulched with various materials or not mulched. At the end of the nine years, the mulched shrubs “continued to have a significant growth advantage over unmulched plants.” In addition, there was no significant nutrient “tie-up” effect, that is, the myth that wood mulch reduces the amount of nitrogen in the soil that is available to plants. There actually were higher nitrogen levels in the leaves in the mulched plots. This expected disadvantage is one reason people cite for avoiding the use of wood mulches.

While putting wood chips on garden beds is a hard job, it has a great reward in healthier plants and soil. For more information on mulch options, see ’s fact sheet on mulch at https://extension.illinois.edu/sites/default/files/how_to_select_mulch.pdf.
*In the Journal of the National Association of County Agricultural Agents, December 2022.(https://www.nacaa.com/journal/c6b61258-c158-478e-b92d-a6aaa73a71b8).

05/27/2026

Learn more about pollinators.

Flitting from one flower to the next, pollinators are among the most essential species to sustain ecosystems and biodiversity. In the U.S alone, 150 crops rely on pollinators to produce a third of its food supply.

This June, celebrate National Pollinator Month by learning how to provide food and shelter to pollinators, and become more aware of native plants that attract them at local Extension Events.

Read more about upcoming events at https://extension.illinois.edu/news-releases/grow-healthier-ecosystems-home-pollinator-month

Add these pollinator events to your calendar at https://extension.illinois.edu/newsletters/global/2026-pollinator-month

Photo Credits to Taryn Bieri

05/25/2026

The weekend before Memorial Day often finds members of the American Legion handing out red paper poppies. The poppy symbolizes the blood shed by those who fought and those who continue to fight for our country. After World War I, the fields of Belgium and France were covered with these flowers, thought to be the result of lime and soil disruption from rubble left behind. They were immortalized in the poem “In Flanders Fields”.

Poppies can be grown in the Midwest, both annual and perennial. They grow best in full sun to part shade, in well-drained soil. They do not thrive in hot temperatures, so they bloom early. They have few pest or disease problems and are easy to maintain. Beyond the stunning display of poppies floating over your garden, they make good cut flowers. If using them as cut flowers, they last longer if you sear the stem with a flame to seal in moisture.

The poppies in European fields are corn or Flanders poppies (Papaver rhoeas). The annual Shirley poppy is in the same class. Shirley poppies are available in a wide variety of colors and have a white center rather than the typical black one. They are easy to grow from seed. If started indoors it is best to use peat pots that can be planted directly into the garden in early spring. They don’t like their roots disturbed. If directly sowing in the garden, seeds should be sown very early, 4 weeks before the last frost date.

The most popular perennial poppy is the Oriental poppy (Papaver orientale) that is found in shades of red, orange, white, and pink. Leaves appear first in spring, a clump up to 12 inches tall. Flowers then appear above the leaves in May and June. In bloom they grow up to 3 feet tall. The plant goes dormant and foliage disappears during the heat of summer. Beyond the large blooms, the buds and seed pods provide additional seasonal interest. Root cuttings and seeds are the most common method of propagation. https://extension.illinois.edu/blogs/ilriverhort/2016-06-17-poppies

Another perennial is the Iceland poppy (P. nudicaule). Because it is native to subpolar regions, it is usually grown as an annual in our climate. It is best to treat them as winter annuals, planting them in the fall for spring blooms. They can also be direct sown very early in the spring, as soon as soil is workable. The blooming period is longer than that of the Oriental poppy, from spring into summer, but the flowers are smaller. Colors are pink, white, orange, yellow and red. They can reach 15-20 inches tall.

Try something different in your garden next year and plant poppies this fall. Often you can find potted Oriental poppies in garden centers in the fall. The crepe-paper-like, showy flowers make a lovely addition to any garden. If the seed heads are left on the plants during the winter, they often reseed, so even if they don’t last long in hot summers, chances are good you may have some new ones next spring.

For more information on specific cultivars see Iowa State site: https://yardandgarden.extension.iastate.edu/article/2002/6-21-2002/poppies.html

05/22/2026

Information to be aware of for safety’s sake.

Keep an eye out for poison hemlock and wild parsnip, which are a threat to humans and animals. Both are common across Illinois and are in bloom this time of year.

• Poison hemlock is highly toxic. Ingestion can result in death for humans and animals. It has white, airy flowers and hollow, purple-spotted stems.
• The sap of wild parsnip causes skin blisters and burns 24-72 hours after sunlight exposure. It has yellow, airy flowers and singly pinnate leaves. It is a serious threat to grazing livestock.

Look for these tall, imposing plants in unmowed ditches, fence lines, and overgrown areas. When found, remove or destroy them following control recommendations. Report sightings to property owners and/or managers.

Find out more about how to identify and control these plants:
• Wild parsnip: https://extension.illinois.edu/invasives/invasive-wild-parsnip
• Poison hemlock: https://extension.illinois.edu/invasives/invasive-poison-hemlock

05/20/2026

Burning bush escapes into woodlands and crowds out native understory plants. Swapping it for natives like ninebark, witch hazel, or chokeberry brings fall color and real habitat value.
See more invasive‑to‑native swaps in the latest ILRiverHort post:
go.illinois.edu/ILRiverHortLandscapesthatsupportlife

05/20/2026

Many gardeners can identify insect pests by their habits and the telltale signs of their presence. Sometimes damage can be insignificant or purely cosmetic, other times it can prove fatal.

One insect that is due in the gardens now that leaves a distinct sign is the roseslug (Endelomyia aethiops). You can tell they have been nibbling on your rose leaves because their chewing on the underside of the leaf leaves a windowpane effect. Roseslugs are not actually slugs; they are the larva of the rose sawfly, a plant-feeding wasp, and named such because they excrete a slimy substance all over their bodies. In the Midwest there are 3 types of sawflies that feed on roses. Both the larva and adult wasp all look similar to the naked eye. Larvae of all of these look like pale green caterpillars with dark heads, and adults are dark-colored, about 1/3 inch long, and wasp-like. For more specific information on the three, see University of Wisconsin website: https://insectlab.russell.wisc.edu/2022/05/31/whats-eating-my-roses-in-spring-sawflies/

Roseslugs and sawflies will feed on any rose… wild, cultivated, climbing, shrub…they are not particular. Sawfly damage is usually minimal and cosmetic. They all feed on the bottom of the leaves and either leave small holes or windowpane spots where only the underside of the leaf has been eaten. Some may also eat along the edge of the leaf. The good thing is they are only around for several weeks in May and June, early in the season; thus the plant will often produce new leaves to cover or replace the damaged ones. Damage is only serious if there is a large number, where the leaves may be skeletonized. After larvae feed, they drop to the ground to pupate and stay underground all winter. Adults emerge in spring and lay their eggs on the bottom sides of rose leaves.

Now what to do once you find these things chewing on your rose leaves? Since damage is usually minimal, you don’t need to do anything. If you don’t want to just leave them, you can squish them with your fingers, drop them into a bucket of soapy water, blast them with the hose, or just remove the leaves they are feeding on. If you are worried about the looks of your roses or if you have a lot of larvae, you can apply insecticidal soap or Neem oil. Organic options are Pyrethrins or Spinosad. If you use a spray for shrubs, be sure to read the label so as not to do harm to any other insects. Always read the label!

Some more good information about sawflies from : https://extension.illinois.edu/blogs/good-growing/2024-06-07-why-are-there-holes-my-roses-roseslugs and North Carolina State: https://content.ces.ncsu.edu/roseslug-or-rose-sawfly

05/18/2026

If you noticed some mysterious pathways with small holes in your garden or lawn this spring, it may very well be a sign of voles. Voles are small rodents--not to be confused with moles--that can cause damage not only to turf grass, but to trees and ornamental plants as well.

Voles are herbivores and feed mainly on the stems and leaves of grasses, but they will also eat other green vegetation and fruits. “Voles do not hibernate and are active throughout the year. During severe winters and snow cover, when green vegetation is scarce, voles often girdle tree trunks and roots killing or damaging trees and shrubs.” (https://turf.purdue.edu/voles-remember-the-v/ ) They make trails from their burrows and will also make small holes about 1 inch across, both telltale signs of vole activity.

Voles are very prolific breeders; their populations cycle, so that every few years there will be a population boom. They are a prime food source for many predators such as snakes, hawks, owls, and foxes. All this means that some years they may not cause a problem in your yard and garden, while other years they can be a serious pest.

Total control of voles is impossible, but there are several steps you can take to keep their numbers down. Yard sanitation is the first step: remove woodpiles and other debris from the ground, keep grass trimmed, and bushes trimmed up from the ground. If you have a small population, trapping may also be effective. Set out standard mouse traps baited with peanut butter near the tunnels. Be sure, though, to cover the traps with a heavy pot or bucket so that pets and wildlife don’t accidentally find them.

Commercial vole repellents are available, but their effectiveness has not been proven. There are also pesticides available for home use, but consider the possible effects on wildlife before resorting to these. If you do choose to use a pesticide, always follow the label directions carefully.

More information on identifying and controlling voles can be found at https://extension.umn.edu/planting-and-growing-guides/vole-damage and at https://pubs.extension.wsu.edu/product/vole-management-in-home-backyards-and-gardens-home-garden-series

05/18/2026

Protect your back, knees, and joints this gardening season! Dr. Molly Knoblett of Athletico Physical Therapy will share practical tips to prevent strains, repetitive stress injuries, and pain so you can enjoy gardening longer at Body Mechanics and Injury Prevention in the Garden. Register today at go.illinois.edu/CCMGgardensafe

05/15/2026

Who doesn’t love seeing butterflies in their garden? Besides being beautiful to look at, they are an important part of our ecosystem, including pollinating flowers. If you want to increase the number and variety of butterflies in your garden, the first step is learning what plants they need to complete their life cycle, starting with host plants.

What are host plants? These are the plants that adult butterflies seek out to lay their eggs on and which will provide the necessary food for the caterpillars—the next stage in the butterfly life cycle. Most people are aware that the Monarch butterfly needs milkw**d for its eggs and caterpillars, but other butterflies have their own culinary tastes. For example, Painted Ladies and Pearl crescents prefer asters while the Silvery Checkerspot prefers coneflowers and Black-eyed Susans. The Black swallowtail feeds on dill and parsley while the Zebra swallowtail is more finicky and feeds only on the pawpaw tree. By the way, this is a good reminder not to immediately reach for a pesticide when you see something wriggly eating your plants—they could very well be baby butterflies!

While you may not have room to plant a host plant for every type of butterfly, you can help many of them by planting more natives. Also, planting a few herbs like dill and parsley is a simple addition to any garden and doesn’t take much space. Keep in mind, though, that if you are also using these herbs for cooking to check for little residents before snipping!

For a more comprehensive list of host plants, check out this article from Iowa State https://yardandgarden.extension.iastate.edu/article/2021/03/gardening-butterflies and from Penn Statehttps://pollinators.psu.edu/assets/uploads/documents/Butterfly-Host-Plants-022518.pdf

Also, fun fact, oak trees support 897 caterpillar species in the U.S. according to University Delaware entomologist Dr. Doug Tallamy (as quoted in https://www.nytimes.com/2021/03/31/realestate/oak-trees-why-you-should-plant.html).

05/12/2026

Love gardening but not the aches and pains that come with it? Join Dr. Molly Knoblett, physical therapist and Clinic Manager at Athletico Physical Therapy in Champaign, for Body Mechanics and Injury Prevention in the Garden to learn smart body mechanics that can help prevent common gardening injuries and keep you growing strong for seasons to come! 🌱

Visit go.illinois.edu/CCMGgardensafe to register!