Trees

A pawpaw tree outside a brick building

How sunlight can change tree shape

The Garden Scoop
Several years ago, we had an extra pawpaw tree (Asimina triloba) after all the plants were distributed at the East Central Illinois Master Naturalist’s Annual Native Tree and Shrub sale. Since this poor tree had no home, we decided to plant it outside one of the staff entrances at the...
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Brown leaves hanging off an oak tree that were damaged by cicadas

How to identify cicada damage on trees

The Garden Scoop
The signs of this year’s historic cicada hatch are still around, although all of our periodic cicadas are now quietly underground, feeding away on tree roots for the next 13 years.  After piles of molted shells and dead adult cicadas earlier in the summer, we are now seeing their signature on...
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Magnolia scale on a magnolia tree.

Managing Magnolia Scale

The Garden Scoop
Magnolias are some of the most popular ornamental trees across the US.  Known for spectacular flowering displays, they come in various shapes and sizes, from smaller shrub-sized plants to medium-sized shade trees.For the most part, these trees are usually a pretty safe bet in Illinois gardens...
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A picture of tree roots that have been pulled out of the ground

Clearing misconceptions around tree roots

The Garden Scoop
Roots are always underfoot, whether it’s a forest or prairie, your yard, or a local park; these all-important plan structures fill the upper layers of soil and quietly do their work to support the plant world.  Since they are often “out of sight, out of mind,” there are many common...
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redbud flower

Spring flowering trees and shrubs

The Garden Scoop
Signs of spring are beginning to pop up if you look close enough.  In the last week or so, I’ve noticed harbinger of spring (Erigenia bulbosa) and spring beauties (Claytonia virginica) in natural areas. The beginnings of Virginia bluebells can also be found as their...
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Pruning cuts can tell a tale

If you are just dying to get into the garden these days, there is one essential practice that is best done during winter dormancy. Pruning is perhaps the most important landscape maintenance task performed in any space that hosts woody plants. There is a large list of benefits to plant health,...
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snowy road with snow-covered trees

Extreme winter cold and plants

The Garden Scoop
Extreme winter cold is something that can keep gardeners up at night.  Since plants are dormant, there is little we can do in the way of plant health care and that can be a real helpless feeling.  The extremely cold weather back in December certainly raised concern and my office received...
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assorted cut evergreen trees and wreaths for sale at a market

Christmas tree selection, sustainability and identification

This time of year, many folks have questions while searching for the perfect Christmas tree.  In recent years, I have written several blog posts on this topic, covering various aspects of Christmas tree care, identification, selection, and sustainability. Take a look at our collection of...
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What Happened to my Dwarf Spruce Tree?

There are many oddities of the plant world that are hard to pass up without some questions.  Based on the perspective of the beholder, some of these strange phenomena may lead to either wonder or concern.  One plant that has fueled both questions of marvel and worry is the popular...
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White pine has beautiful color that is expressed in the yellow innermost needles this time of year.

Fall Color from Conifers

The beauty of fall is upon us with splashes of exorbitant color all around the landscape.  In the past week, red maples (Acer rubrum) have nearly reached their peak color for the season, displaying fire-red leaves that scream for attention.  The brilliant yellows of shagbark (...
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Sick tree

Using Phenology for Ornamental Pest Control

The Garden Scoop
The timing of spring can vary each year based on weather, but there are always ques in nature that line up in similar fashion year after year.  While climatic conditions on exact calendar dates my vary, the sequence of emerging biota is consistent and based a long evolutionary history which...
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Trees in our communities enhance learning

The benefits of green space in urban areas has long been documented to improve our lives in a wide variety of ways.  However, recent research has Illuminated the special role that trees and larger woody plants serve in our communities.  Beyond ecological and environment benefits, these...
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Leaf

How accurate are photo-based plant identification apps?

Plant identification can be incredibly challenging for beginning botanists or even experienced plant people. There are tons of terms to learn and understand just to start identifying plants by leaves and other plant parts. Throw in a leafless winter, and it makes for a difficult skill to...
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stacked firewood

Invasive species hitchhike on firewood

The Garden Scoop
Nothing beats the warmth of a crackling fireplace on these coldest days of the year.  Each winter, as my family enjoys the cozy warmth of our woodstove room, I’m always thankful for the firewood supply we’ve been fortunate enough to accumulate over the past season. I enjoy the process of...
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What is the most sustainable Christmas tree option?

Each year, millions of fresh cut Christmas trees are sold across the country adding to the hustle and bustle of the holiday season.  Have you ever considered the sustainability of a fresh cut tree versus an artificial tree?  Fake trees can last for many years, but what is the impact of...
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How to identify common holiday evergreens

Evergreen foliage has long been a traditional holiday decoration since it encapsulates the green of the growing season well beyond the first frosts.  The holiday season is an excellent time to practice your evergreen tree identification on the many non-natives that are so plentiful at retail...
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A mature American elm at Morton Arboretum in Lisle, IL

Breeding elms to combat Dutch elm disease

The Garden Scoop
Over this past week, the fall weather has brought bare branches to the previously color-filled canopies of so many trees in the landscape.  As the autumn leaf drop has progressed, there are several elm trees that I pass each day which have held onto their fall color and really look spectacular...
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Smooth sumac is a commonly occurring native plant that boasts a spectacular fall display of fiery red leaves.

Native Shrubs for Fall

Shrubs are often overlooked in autumn, typically playing second fiddle to overtopping shade trees that steal the fall display.  However, quite a few deciduous shrubs have spectacular fall color to offer in the landscape.  In many settings these smaller woody plants can help provide eye-...
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Tree Root Collar Disorders

The root collar of a tree can be defined as an area of the lower trunk that transitions from trunk tissue to root tissue.  It is typically associated with the basal flare, or the trunk flare of the tree, which is the wider portion of trunk that insects the ground.  In recent years,...
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Urban trees provide a variety of benefits which are going to be increasingly important as climate change impacts Illinois in coming years.

Climate Change Adaptations for the Urban Forest

Last month, the US Forest Service released a technical report titled, “Climate Adaptation Actions for Urban Forests and Human Health.”   The report includes a summation of the current research related to urban trees and climate change, looking at how trees benefit human health, how...
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As the summer heat intensifies and rainfall dwindles, watering newly planted trees and shrubs becomes incredibly important.

Watering Trees and Shrubs

Although rainfall has been significant so far this summer, newly planted trees and shrubs need watering as daily high temperatures creep up and rain dwindles during the drier part of our summer.  The next few months can be critical for woody plants struggling to become established in their...
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‘Forest Pansy’ is a cultivar of our native redbud that offers unique purple foliage.

Adding purple shade trees to your landscape

The ornamental value of landscape trees can be weighed by a variety of attributes, from interesting bark in the wintertime or colorful blooms in spring to the character of leaves that persists during the growing season. However, the foliage that embellishes branches to create a summertime...
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This year, periodical cicadas in Brood X will emerge across Indiana and a small, 4-county area of central Illinois.

17-Year Cicadas of Brood X

The Garden Scoop
Over the next few weeks, some of central Illinois will experience a rare phenomenon that only occurs every other decade.  As soil temperatures warm, millions of insects will emerge from the ground in forests, city parks, yards and gardens.  They will carefully navigate the terrain and...
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Redbud is a fantastic spring-flowering tree offering the best floral display of any Illinois native tree.

The top four spring-flowering trees to plant

The Garden Scoop
Spring is a time of abundant blooms as well as one of the best times of year to establish new woody plants in your landscape. This year, consider adding one, or all, of my favorite Illinois native spring-flowering trees to your landscape, and you’ll enjoy spring floral displays for years to...
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This young red maple could benefit from corrective pruning to establish a central leader that is free of competition from adjacent limbs.

Shade Tree Pruning

Wintertime offers few activities out in the garden, other than filling bird feeders and carefully watching dormant plants for any sign of awakening as spring nears.  However, winter dormancy is the ideal time to prune woody plants.  With trees and shrubs inactive in their winter slumber,...
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River birch is a native tree with excellent winter appeal from its beautiful, exfoliating bark.

River Birch

The snow-blanketed wintertime landscape often lacks the beauty we can recall from other times of the year when plants were in bloom or filled with wonderful green foliage.  It leaves both humans and wildlife searching for plant life that retains interest either in the form of ornamental beauty...
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Gymnosperms, like this Colorado blue spruce, are a group of nonflowering plants that emerged several hundred million years before flowering plants (angiosperms) entered the evolutionary history of the plant kingdom.

Angiosperms vs Gymnosperms

The plant kingdom has not always had the diversity we know today.  It has taken hundreds of millions of years of evolution to bring about the diverse, complex group of flowering plants known as angiosperms.  And for many millions of years prior to the emergence of angiosperms, the plant...
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The frosty accumulation of ice crystals on these spruce needles resulted from the wafting spray of an adjacent (untreated) roadway and serves to illustrate how salt spray can accumulate on plant parts.

How winter salt can damage landscape plants

Deicing salts are essential to winter travel in Illinois and provide necessary safety in a landscape setting by melting dangerous ice on precarious steps, sidewalks, entryways, and other areas of frequent foot traffic. However, winter damage from salt can be a major problem in some landscapes...
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Ice accumulation yesterday resulted in damage to many trees and shrubs in our area.

Ice Accumulation on Trees and Shrubs

Freezing rain is a regular part of winter weather patterns in central Illinois, resulting in occasional ice storms that can damage property, take out utilities and wreak havoc on tree canopies.  By meteorological definition, an ice storm occurs when ice accumulation is greater than 0.25 inches...
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Trees and other woody plants grow from buds at tip of each limb which release hormones to suppress growth of other buds lower down the stem.

How Woody Plants Grow

Woody plants are some of the largest and most long-lived plants in the landscape, forming the majestic and expansive canopy of our urban and natural forests.  With all of this wonderful woody growth, have you ever stopped to think about why woody plants attain greater height than their smaller...
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Selecting a Christmas Tree for the Holidays

Thanksgiving brings us a feast that, for many gardeners and naturalists, signifies the final harvest and close of the growing season. As we draw further away from the growing season and nearer to the winter solstice, many of us turn our focus to bringing light and greenery into our homes. Whether...
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Metal hardware cloth is a great material to protect young trees and shrubs from winter browsing wildlife.

Winter Protection for Newly Planted Trees and Shrubs

Fall is an excellent time to add new trees or shrubs to the landscape and many of us have already taken advantage of mild weather and sunny days to get new plants in the ground.  With the lion’s share of work complete after digging, planting and mulching are finished, we often overlook some of...
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Honey locust can have large and terrifying thorns making it one of our spookiest native trees.

Top Four Spookiest Native Trees

Images of witches, skeletons, and other specter abound this time of year.  But we really don’t need to look much beyond the natural world for a dose of spooky entertainment? This week, I’ve compiled my list of the top four spookiest native trees that all offer some great Halloween-related...
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Bald cypress is an Illinois native plant only know to occur in extreme southern Illinois. While it does wonderfully when planted here is central Illinois, should it be considered native?

How Native is Native?

The term native often means different things to different people.  Most definitions draw a line between geography and time scale which typically is demarcated by the point of human intervention or influence on the landscape. I really like this definition from the Forest Service in 2012, “A...
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This pin oak tree tested positive for bacterial leaf scorch and displays the most distinctive symptoms characterized by brown leaf margins, a colorful band and green tissue along leaf veins.

Bacterial Leaf Scorch Infecting Illinois Oaks

Shade trees are some of the most valuable plants in most urban landscapes.  They provide energy saving shade as well as valuable habitat for wildlife in a sometimes otherwise inhospitable built environments.  However, a mature shade tree takes considerable time to develop the canopy and...
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The alien-looking fingers protruding from these crabapples release spores that can infect trees in the juniper family to perpetuate cedar-apple rust disease.

Plant Pathogen Spread

Whether its fungi, bacteria or even viruses, one of the most important aspects of plant disease management is stopping or limiting the spread of infectious pathogens.  I have always been fascinated by the way these tiny organisms, rarely visible to the naked eye, make their way through nature...
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This two-spotted bumble bee forages pollen on the flower of a spirea shrub

Early History of Pollinators and Plants

This past week was National Pollinator Week, a time set aside to celebrate the amazing and monumental task that pollinators perform each and every growing season.  Worldwide, animals pollinate about seventy-five percent of all plant species, and about ninety percent of all flowering plants....
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Sycamores across central Illinois are late to leaf out this year due to a commonly occurring fungal infection.

Sycamores and Anthracnose

It has been another difficult spring for sycamore trees across central Illinois as near bare canopies of this tree stick out among the fully developed leaves of neighboring trees.  However, this doesn’t necessarily spell doom for your sickly looking sycamore.  It’s all caused by naturally...
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Newly planted urban trees are at risk of mortality if proper after-planting care, such as mulching and watering, is not carefully tended.

Urban Tree Planting

Spring is a time of an awakening plant world full of blooms and endless possibilities for the coming growing season.  It’s a time that many of us think about updating our landscaping, making it the most popular time of year to plant trees and shrubs.  When you combine the mild...
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Hollies are symbolic of the holiday season, providing beauty in the landscape as well as abundant berries for native birds. Photo Credit: Diane Plewa, Illinois Extension Plant Clinic

Holly for the Holidays

Broad-leafed and evergreen holly species have long been a symbol of Christmas and other winter holidays and traditions.  The dark green, prickly foliage combined with contrasting bright red berries can really be a show stopper in the winter landscape providing both ornamental beauty and food...
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This young swamp white oak (Quercus bicolor) has retained its leaves while the maples on either side have already dropped theirs. Many of our native oaks keep their leaves all winter as young trees.

Why do some trees retain leaves over winter?

Not all trees shed their leaves in coordination during fall. You may have noticed that some trees are still holding their leaves this week, and many of those will likely hold them until spring. Each winter, I get a number of questions on this topic as folks ponder the “not-so-deciduous” deciduous...
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Fall Color in Oaks

Fall color is beginning to paint tree canopies around central Illinois, making the next few weeks prime time for taking in the beauty.   Among our native trees, sweet gum (Liquidambar styraciflua), red maple (Acer rubrum) and sugar maple (Acer saccharum)...
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Benefits of Urban Trees

Urban trees provide beauty and definition to our cities and most of us have a love and appreciation of these denizens of the boulevard and backyard.  In recent years, a body of research has emerged showing even greater benefits than previously understood to both the environment and our...
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Fall Tree Planting

Most folks think of spring as the ideal planting time for trees and shrubs.  However, fall offers a nice planting window with some added benefits over the spring season, making it my favorite time of year to establish woody plants. Fall weather can create ideal planting conditions, with...
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Poisonous Plants

How many times have you been kept up at night worrying about a poisonous plant?  Hopefully, for most of us the answer to that question will be ‘not many’.  For better or worse, humankind has not always had a well-defined separation from the plant world as we often see today.  With...
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The green foliage in this picture is bush honeysuckle, which is an invasive species that dominates forest understories in Illinois. If not weeded out...

Weeding out Invasives

The management of Illinois’ forests has become an increasingly difficult task for landowners focused on maintaining and enhancing native plant diversity. I have often thought of it as a similar process to weeding a vegetable garden, with a diverse mix of our native forest trees as the vegetable...
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illinois forest

Forest Management, HIPP and RCPP

The management of Illinois’ forests has become an increasingly difficult task for landowners focused on maintaining and enhancing native plant diversity.  I have often thought of it as a similar process to weeding a vegetable garden, with a diverse mix of our native forest trees as the...
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This rhododendron shoot is infected with the pathogen Phytopthora ramorum, displaying the typical symptoms of ramorum blight. PC UI Plant Clinic

Rapid Response to Ramorum Blight

In early July, the Illinois Department of Agriculture submitted a press release detailing the detection of a new pathogen in Illinois that threatens our native oaks. This non-native pathogen is the causal agent for a very serious disease known as sudden oak death. However, there may be some good...
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Hackberry Gall

The Garden Scoop
As you might imagine, my family spends a considerable amount of time out observing the wonders of the natural world, and I am always fascinated by the way my kids view and interpret things in nature. Many times, their straightforward and simple perspective makes me feel like such a dummy. There is...
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Garden Storm Damage

Imagine spending years establishing and cultivating a beautiful landscape on your property, only for it to be destroyed in a heartbeat from a severe storm.  Couple that with a limb through your roof and you have a real disaster on your hands!  Who do you call?  What do you do about...
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Maple Seed Production

What kid doesn’t love those maple ‘helicopters’?  I grew up with two large silver maples (Acer saccharinum) in our yard and can always remember the late spring ritual of playing with one of the best toys ever produced by nature, the maple samara.  These winged seeds rapidly go...
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Apple trees in our area are in full bloom this week. Unlike peach trees which suffered cold damage, many apple trees in central Illinois seem to have endured.

Fruit Trees and Winter Injury

Winter injury is a common problem among fruit trees grown in our area and this year’s up and down spring temperatures resulted in damage to flower buds across central Illinois.  Cold weather in some years can bring damage to many ornamental tree species as well, impacting much anticipated...
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Osage Orange

In many communities there are iconic trees that nearly everyone recognizes and admires in passing during daily life.  The spreading, stately tree at the corner of University and Prospect Avenue in Champaign is certainly a historic and interesting specimen.  I cannot count the times that...
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2019 Gardening Goals

Winter is an excellent time for reflection on the past year’s growing season and any gardening successes or failures to account for next year.  In this season of multitudes of seed catalog mailings, I have found it to be an ideal time to set gardening goals for the coming year during the down...
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Ice Storms and Tree Damage

Historically, our part of Illinois has been more prone to ice storms than the northern or southern part of the state.  Based on over 50 years of weather data from the Illinois State Water Survey, our area of Illinois (including Springfield, Bloomington and Champaign) is likely to have an...
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Tree Bark

Winter time is somewhat of a downtime for deciduous trees.  After a growing season’s worth of beautiful foliage, culminating in the wonderful fall display of color, woody plants enter the long, cold season of dormancy that is part of their annual life.  For many of us, this is not a time...
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Christmas Tree Selection

Everyone has their own idea of the perfect Christmas tree.  While I am not a person that picks the proverbial “Charlie Brown Tree”, I have certainly felt pity on the less attractive trees on the lot in years past.  Whatever your taste, a fresh cut Christmas tree adds a certain bit of...
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Fall Color

Illinois forests are dominated by a mixture of eastern deciduous forest trees and many of our urban areas mirror this forest composition creating a wonderful palette of fall colors each year as the growing season concludes and tree leaves senesce, giving way to winter dormancy.  As a tree-...
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Larch

Last weekend’s fall weather has certainly set leaf drop into motion for the year.  I noticed some of the early droppers stating to thin their canopy as many of the walnut around our property are already yellowing and loosing leaves.  Cottonwoods are half bare, dropping more leaves each...
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a black walnut tree

Black Walnut

The Garden Scoop
Anyone with a mature black walnut (Juglans nigra) on their property is likely aware that fruits are ripe now, and the baseball-sized, green bombs are beginning to fall with each slight gust of wind or, at times, seemingly at random. This native tree is prevalent throughout central...
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Sycamores

Our native sycamore tree (Platanus occidentalis) is known for its extraordinary exfoliating bark which peels off to expose the beautiful creamy white and greenish colors beneath creating a camouflage-like appearance.  This summer many area sycamores are shedding bark at alarming rates...
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Flowering Crabapples

In the past week or so, crabapple trees have stolen the spring flower show among our blooming landscape plants.  These beautiful trees produce abundant flowers for up to 4 weeks each spring, with one of the best, most showy displays of any ornamental tree species.  They pick up where the...
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Saucer magnolia is currently in full bloom in our area with an abundance of white to pinkish, showy flowers

Magnolia Pollination

Although spring was late coming this year, it has finally sprung, and with it both star magnolia (Magnolia stellata) and saucer magnolia (Magnolia x soulangeana) are in bloom. These beautiful ornamental trees, native to Asia, provide about a...
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Winter Damage to Evergreens

Evergreen plants, which retain their leaves (or needles) throughout the seasons, are some of the showstoppers of our landscapes in winter.  They provide some much needed color in a world devoid of the green, chlorophyll-laden foliage we have throughout the growing season.  Although...
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Pawpaw

Spring is a time of swelling buds and wildflowers in Illinois forests.  However, the flowering display of some plants may be overlooked if you aren’t observant.   The tiny, indiscrete flowers of pawpaw (Asimina triloba) are often unnoticed by humans since they appear in...
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Making Maple Syrup

Maple syrup is made from just one ingredient, maple sap, which magically flows from trees in late winter.  It takes specific weather conditions this time of year to create sap flow, caused by nighttime temperatures below freezing followed by daytime temperatures above freezing (ideally 20⁰F at...
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Local Tropical Getaway

Recently, on a cold, single-digit day I paid a visit to the University of Illinois Plant Biology Greenhouses.  Since it was quite sunny and warm under the glass greenhouse roof, my mind drifted far from the snow and ice that was entrenched outside.  Nothing can beat the tropical ecosystem...
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2018 Gardening Goals

Winter is an excellent time for reflection on the past year’s growing season and any gardening successes or failures to account for next year.  In this season of seed catalog mailings and New Year’s resolutions, I have found it to be an ideal time to set gardening goals for the coming year...
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The Norfolk Island Pine

The Norfolk Island pine (Araucaria heterophylla) is a common houseplant that is often sold around Christmas time due to its Christmas-tree-like appearance.  However, in its native range, it is quite different than the 1-5 ft houseplant we know it as, reaching heights of 150-200 feet...
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Fall Color in Conifers

Over the past several weeks, our fall color has peaked here in central Illinois.  The stunning bright red to pink hues of red maple (Acer rubrum) were exceptional this year.  Who could miss the rainbow of color from sweet gums (Liquidambar styraciflua), covering yellows...
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Reaping the Apple Harvest

One of the most glorious aspects of fall is bringing in the apple harvest.  Every year around harvest time I wonder when exactly to pick my apples, which raises some questions.  What does the apple maturity chart say for this variety? Has the weather this year impacted fruit quality?...
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Dawn Redwood: A Living Fossil

Have you ever wondered what the earth looked like when the dinosaurs roamed?  Humans didn’t realize that we have a living fossil among us that offers a glimpse into the past until the 1940s when the dawn redwood tree (Metasequoia glyptostroboides) was “discovered” by scientists in...
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Early Fall Color

Do you have a tree that is displaying fall color right now?  Although it may be beautiful, this may be a sign of health issues.  In our area, most trees do not begin to change colors for the season until October.   A branch or two here and there or some yellow leaves in the...
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