Last week, I reviewed the history of USDA Plant Hardiness Zone Maps (PHZM) and their relative change over recent time. These maps are intended to be a guide for gardeners attempting to predict the potential for winter injury to plants, which is a key factor in establishment and successful cultivation of woody and herbaceous perennial plants. This week, I will look at how gardeners should interpret these maps now and in the future as the impacts of climate change accelerate.
The USDA Plant Hardiness Zones are a standard that most gardeners consider when selecting plants suitable for their local climate. These maps show us the mean annual low temperature for a given location, which helps distinguish the relative cold hardiness of plants, insects and other biota.
Poinsettias (Euphorbia pulcherrima) are the most popular holiday plant in US households. It is estimated that over 30 million poinsettias are sold each year around the holiday season, accounting for about one quarter of all flowering houseplants sold in the US, year-round. That is a staggering statistic, making it the highest-selling potted plant nationwide. It is so interesting to me that a plant which most of us purchase, enjoy for the holiday season and discard when blooms fade can be so widely sold.
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 nostalgia to holiday décor but takes a keen eye to select the right tree for your home, along with some forethought and proper care to ensure quality throughout the holidays.
Nothing symbolizes the holiday season to a horticulturalist like a holiday cactus in full bloom. These fascinating plants are cacti, but not at all like the full-sun, desert loving specimens we commonly think of. Instead, these plants hail from the treetops of forests in Brazil, which is quite different than the desert ecosystems associated with other species of cacti. They are all epiphytes, living in mostly shaded tree tops and rooting into pockets of organic debris instead of soil.
One of the single best things you can do to improve your garden soil is to add organic matter. By adding significant amounts of organic matter, you are putting fuel back into the nutrient cycle which naturally adds plant nutrients to our soil and lessens (or eliminates) the need for fertilizer. Soil structure is improved by boosting organic matter content, making soils better able to retain water and nutrients.
The world of horticulture is ever changing with an increasing interest among plant lovers for more and more digital media. While the internet has vastly expanded the amount of plant information available to the public as text, other forms of digital media, such as podcasts, YouTube videos, Facebook pages and even online Master Gardener training, are forging the way for new educational opportunities to expand our experiences with plants.
Autumn is not only a time of brilliant fall colors, but also a time to observe the annual bird migration that spans our continent. Many of our feathered friends travel amazingly great distances to reach warmer climates with abundant food for winter. This lengthy journey spans thousands of miles, requiring birds to expend a ton of energy in the effort. As our avian counterparts make their annual retreat to warmer climates, it is critical that they build up fat stores prior to embarking on their trip and maintain this energy reserve by finding more food along the way.
Most of us think of tree leaves when we think about beautiful fall foliage, but many ornamental grasses provide wonderful fall color that often extends well into the winter season. Right now is an excellent time to observe these grasses in the landscape and consider how we might integrate them into our own gardens.
In recent years, herbs have gained a larger presence in my home gardens. Not only do these plants provide wonderful, fresh garnish for many of our favorites recipes, but they can also be a source of ornamental value as well as great pollinator plants when in bloom. Many herbs are touted as tough perennial plants, and many are so, but rosemary (Rosmarinus officinalis) can be a challenge to keep going in the garden.
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-lover, this time of year is most definitely my favorite, from an ornamental standpoint. It far outweighs the sometimes hard to detect spring flower structures that our mostly wind pollinated native trees produce.
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 time the wind blows. One particular group of trees always draws my interest this time of year as I wait for their fall display - the deciduous conifers.
This week marks the half way point for the 2018 Illinois Ginseng Harvesting Season, which runs from the first Saturday in September through Nov 1. Did you even know that ginseng grows in Illinois, let alone the fact that there is a regulated harvest of this valuable native plant?
Since its beginnings in 1997, the Idea Garden has been maintained by the Champaign County Master Gardeners and ever-improved throughout the years. This beautiful, yet educational, community garden has grown to occupy over 15,000 square feet of the University of Illinois Arboretum, near the corner of Lincoln and Florida Avenue in Urbana.
During the growing season, questions about lawn or turf care are quite common at the Champaign County Extension office.
The Douglas Discovery Garden is an outstanding gem of Vermilion County and the Danville area. It offers a wide variety of gardening applications for area residents to observe and learn from so they can apply these practices in their own gardens. The beautiful space also has an interesting history of learning behind it, or some may say underneath it.
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 Illinois, thriving on our deep, fertile soils to reach heights up to 100 ft. When compared to other Illinois forest denizens it has some unique and interesting characteristics that set it aside from others.
Native plants offer a whole suite of ecosystems services that are often taken for granted. The faunal associations with our native flora run deep and, through this plant-animal connection, support the ecosystems of the natural world here in central Illinois. Planting native species, even on a small scale, can have a profound impact on the wildlife of Illinois if gardeners and landscapers start to adapt their designs to include more native plants.
In recent years, as interest in more sustainable agricultural practices has grown among home gardeners, organic pest control options have become widely available in many retail outlets and garden centers. I use many of these products in my own garden and find their origins in nature and modes of action against pests quite interesting.
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 which has prompted folks to question the health of their trees.
Garlic is a long-season, over-winter crop that does best when planted in the fall. It can then be harvested in the early summer, which allows space for another summer crop. This is rather unusual timing in the gardening world and it has always interested me for that reason. Planting garlic is a great way to end the gardening season by caching away a crop for early harvest next year.
The iconic monarch butterfly (Danaus plexippus) has become somewhat of a poster child for the plight that many pollinators face, and for good reason. Monarch populations have experienced drastic declines in recent years for a variety of reasons, some which researchers are still trying to explain. The monarch’s charismatic appearance and large home range, spanning much of the US, has made it familiar to most anyone who has ever caught butterflies as a kid or observed visitors to their flower garden.
Recently, my wife, Amanda, noticed that something was chewing on the nice stand of kale she planted in our vegetable garden. Initially, I brushed it off to the usual, acceptable amount of insect damage kale can withstand and still produce a harvestable crop. Typically, kale has some insect visitors that prematurely harvest some of the foliage, but we’re always OK with a little damage as long as they leave enough foliage for us to harvest throughout the season.
Eleven years ago, the US Senate unanimously approved the designation of a week in June as National Pollinator Week, marking a huge step in recognizing both the value of our pollinators and the plight they have faced nationwide. Governors in all 50 states have also recognized the same Pollinator Week in their states. This week (June 18-24) is National Pollinator week, the perfect time to reflect on the value of these hardworking animals.
Visitors to the downtown Champaign area last month may have noticed an odd addition to the One Main Development landscaping. Over the course of May, an increasing number of mysterious white trees appeared out of nowhere. Who placed these ghost trees? Where did they come from?
Master Gardeners across Champaign, Ford, Iroquois and Vermilion Counties are planning a great line up of Garden Walks in the coming few weeks. These events offer a wonderful opportunity to observe the diversity and individuality of garden spaces designed by a wide range of area gardeners. All the gardens included in these events were selected based on their exemplary display and unique features. Participants are encouraged to ask questions and take pictures as each Garden Walk was designed to inspire new ideas among beginning and avid gardeners alike.
As agriculture worldwide continues to advance and innovate in an attempt to feed our ever-growing global population, unique and specialized productions systems are popping up all the time. One such system, referred to as aquaponics, includes an interesting mixture of plants and aquatic organisms. Some folks right here on the University of Illinois Campus are currently using this agricultural system to produce locally grown plants and animals for the menu at Bevier Café.
Koreanspice viburnum (Viburnum carlesii) is one of the centerpiece landscape plants in my backyard, given its prime location at the corner of our screened-in porch and patio. Last fall it delivered a stunning display as foliage turned every shade of yellow, orange and red to purple. This spring it wowed us with gorgeous, showy flowers that persisted for several weeks and were accompanied by its characteristic fragrance which, at times, filled our entire backyard and porch. It’s hard to decide which season’s dramatic display was the best.
In the busyness of spring and planting all our annuals, such as flowers and vegetables, the perennials in our garden often get overlooked. To keep perennial plants performing at their peak, it is necessary to divide them from time to time in order to maintain vigor and flowering. As a general rule, spring flowering perennials should be divided in fall, while late-summer of fall flowering perennials are best divided in spring.
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 magnolia trees left off, often flowering in close succession. The beautiful, tiny flowers are produced from branch tips to the tree’s interior, creating a canopy of blooms.
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 evergreens do go into dormancy during winter, much like their deciduous cousins, their foliage is still subject extreme exposure over the winter months.
If you are like me and your lizard brain apparently controls more of your actions than it should, then you can relate to a primal need to provide habitat for our reptilian friends. Urban and developed landscapes can often be difficult places for reptile and amphibian populations to flourish although our cold-blooded friends do provide many desirable services such as pest control, increasing biodiversity and providing opportunities for recreational observation of wildlife.
With last week’s Easter snow, it is hard to believe that the frost-free dates for our area are fast approaching. Hopefully April will follow a more March-like tradition of “in like lion and out like a lamb”.
The “frost-free” date for the Champaign area is around April 15th, which is the spring median date for overnight lows above 32⁰, meaning we still have about a 50/50 chance for frost on that date. By April 30th, the chance for frost in our area drops to about 10%, with the latest recorded date for temps below 32⁰ being May 21st.
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.
Potatoes are a cool season vegetable that are among the world’s food staples, ranking number four in the list behind rice, wheat and corn. This native to the South American Andes was domesticated around 7,000 years ago. Sixteenth-century Spanish explorers observed indigenous use of the potato during their travels and brought the first specimens to Europe in the late 1500’s.
Last week as I was scouring our backyard for signs of spring, I was pleasantly surprised to notice a tiny, inconspicuous purple flower popping up all around my house, seemingly at random. Since we just moved to this property last summer, I’ve not experienced a full year to observe all the plant life that comes with it.
The tiny, solitary flower I noticed had not opened entirely yet, but it was undeniably identified by the white strip down the middle of its slender, grass-like leaves that characteristically emerge prior to the flowers. It was snow crocus (Crocus sieberi).
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 night and 40⁰F during daytime). The sugar containing elixir that flows from maple trees can then be boiled down to syrup or even further for granulated sugar.
In recent years, orchids have become increasingly popular as houseplants, popping up for sale everywhere from smaller garden centers to big chain stores. Many of us have taken these plants home, given them plenty of TLC, only to be let down when they begin to suffer from wilting and discolored leaves. This has led to a common misconception that orchids are hard to take care of, requiring a special kind of green thumb. In reality, these plants are quite easy
Native plants are typically defined as vegetation growing wild in an undisturbed area at the time that scientific records began. Specific climate, soils and other environmental factors, define a plants native range. Our area is fortunate enough to have a large diversity of both prairie and forest plants that call central Illinois home.
If you have not visited the formal gardens at Allerton Park and Retreat Center, near Monticello, I strongly recommend making the trip. These spectacular gardens combine exquisite landscape design with sculptures from around the globe to create a flowing transition from Robert Allerton’s magnificent, Georgian-inspired home (constructed in 1900) to 1,500 acres of pristine natural areas in the surrounding park. It is truly a remarkable and historic place in Central Illinois, combining art, history, and elaborate design with the flourishing, unimpeded ecosystem of the Sangamon River corridor.
There are few gardening activities available this time of year for those of us with the gardening itch. Indoor herb gardening is one hobby that not only provides an edible product, but also delivers the human to plant interaction that so many of us need.
Recently, I was fortunate enough to tour a unique indoor herb garden on the U of I campus in Urbana. The Bevier Café, located in Bevier Hall, is a student-operated café offering a variety of great cuisine for lunch, Monday through Friday (11:30-1:00) during each semester.
In recent years, I have become more interested in landscape plants that provide some type of culinary use while also providing aesthetic value to my yard. Herbs are a hearty group of plants that can fit into most any landscaping, adding beauty from flowers or foliage, while providing an easy to access fresh supply for recipes. One such herb that has recently piqued my interest is thyme.
Earlier in January, our area experienced extremely cold temperatures, resulting in many days below freezing. With some of our recent warmer days, memories of the cold snap are fading but many folks have asked me questions about how winter temperatures impact insect populations, especially pests like Japanese beetles.
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 created in the Conservatory. It was like a vacation to the tropics right here in Urbana, IL! And to top it all off this facility is free and open to the public on weekdays.
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 during the down time associated with the shortest days of the year.
I have always found it motivational to first focus on what I can accomplish prior to leaf out and the coming growing season. One of the primarily activities that can be done in the dead of winter is pruning.
Last week, I notice the first of an annual pest in our area that is always unwelcome to anyone that gardens. Japanese beetle (Popillia japonica) adults emerge from the ground every June to voraciously consume a plethora of plants. Although there are certainly plants these beetles prefer, their list of potential host plants is quite large (greater than 100 species) including everything from large landscape plants to home vegetable gardens. As these small, metallic beetles buzz about each year, they are most known to feed on foliage, although they often consume flowers, fruits and
Among the plants that grow in the Illinois landscape, poison ivy (Toxicodendron radicans) is perhaps the most notorious. This plant is certainly well known by name among most gardeners, nature goers and outdoor folks, but many are unable to identify it correctly in the field. The result of misidentification and subsequent exposure to the resinous oil, called urushiol, produced by this plant can cause anything from an itchy rash to a severe allergic reaction.
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 month of spectacular flowers each spring. They are some of the first landscape plants in our area to deliver such a showy display; truly one of the most endorsing signs that spring is finally here.
Landscaping with edible plants is my second favorite gardening themes, next to ‘Going Native’. Today, there are a wide variety of plants available that will, not only provide your family food, but also offer many other desirable attributes. In addition, it reduces your carbon footprint by growing some of your own local food.
Are you searching for a unique gift for a friend who just retired? Would you rather be outside in your garden than anywhere else? The University of Illinois Extension Office will be holding Master Gardener Training Classes starting in January 2019. Master Gardeners are volunteers who have a love of gardening and a passion to share it with others, but despite the title, don't claim to know everything about gardening. The program focuses on learning for the love of learning.
'Creating a Holiday Wreath' featuring Master Gardener Mary Stonecipher