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 as they grasp their foliage late into the season.
It is always interesting to observe plant diseases and try to unravel the mystery of how a particular plant became infected and to look toward solutions. So many of these ailments have an incredibly fascinating path to infection, often including multiple species when you consider the pathogen, host and potential vector species.
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 branch structure that provides such benefit, which is the primary reason their high value when weighed against other landscape plants. So, it pays to identify tree ailments effectively in the interest of protecting our investment in time and tree value.
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 to infect new plants. Many of their stories sound like something out of science fiction, often involving multiple species or special adaptations to enter and infect their host.
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 occurring fungi that tends to ebb and flow with our spring weather over the years.
Spring is a great time for planting new trees in the landscape. There is ample rainfall to support your newly planted specimen and the warming temperatures and mild weather motivate many of us to get out in the garden and plant things. However, there are some commonly sold trees that fall onto my “do not plant” list. Many such plants make my list for their invasive habit, but some are on there for insect or disease issues or just generally poor performance as urban trees.
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 news in this incident, thanks to swift action by the agency and others to rapidly identify and quarantine infected nursery plants.
Nothing beats a homegrown tomato! Even when in season, the store bought varieties just cannot compare to a fully ripe tomato harvested at its peak from your own garden. So many gardeners across American choose tomato plants for their garden each year for this reason, making it the most planted garden crop in the US.
The emerald ash borer (Agrilus planipennis) is an insect from Asia that has plagued our native ash trees in Illinois since 2006. This pest was first introduced in 2002 around the Detroit area and has rapidly spread across Michigan and Indiana to infect most of Illinois today. Sadly, the emerald ash borer will eventually wipe out our native ash species in Illinois as we know them, leaving a major void in our urban forests and natural areas since ash is currently so prevalent.
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.
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.
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.
On a cold, dreary day with misting rain last week a group of Master Gardeners met at the Idea Garden, in the University of Illinois Arboretum, for a ritual that has occurred for many years. Each year, most plants in the “Tropicals Section” of the Idea Garden are removed from the ground and transported to nearby greenhouses on Campus. This fascinating process is completed by the Master Gardners with much care and much labor to ensure the sensitive tropical plants are safely tucked away for the winter, to be planted again next spring.