Resources for landscapes and gardens in the Midwest
Landscape Report
Found 484 Articles
Xanthomonas is both an unfortunate, but regular occurrence in the greenhouse industry. Despite the efforts from numerous companies to supply ‘clean plants’, Xanthomonas (and other bacterial pathogens) regularly slip through. This year, it came in on begonia. The pathogen. Xanthomonas is a genus of yellow colored bacteria that infect many species of plants (approximately 400!),[Read More…]
The recent jump from Winter to Summer (with 2-3 days of Spring somewhere in there) got folks out looking at Tulips in full bloom now in northern Indiana. The only thing marring the view in one local planting was an outbreak of tulip fire, caused by the fungus Botrytis tulipae. The disease first shows up[Read More…]
Translated by: Dania Rivera, Ornamental Horticulture Extension Specialist, University of Puerto Rico “El mejor momento para sembrar un árbol es veinte años atrás. El segundo mejor momento es ahora” Anónimo Si vas a hacer algo, hazlo correctamente la primera vez. Esto es cierto para muchos aspectos de la vida, pero, cuando se refiere a la[Read More…]
Biology: Henbit (Lamium amplexicaule) is a common winter annual broadleaf weed found throughout the United States. It can often be mistaken for another closely related winter annual broadleaf, purple deadnettle. Both can be observed by their showy pink to purple flowers which are primarily produced in April, but can appear from March to November in Indiana.[Read More…]
Three different rust fungi cause gall-like protrusions on eastern red cedar (Juniperus virginiana) trees. The bright orange gelatinous galls with tendril-like protrusions (Fig 1) resembling ‘koosh balls’ are caused by Gymnosporangium juniperi-virginianae. This fungal disease is known as Cedar Apple Rust. The galls develop on the cedar tree (Fig 2) and ‘sprout’ fungal spore-bearing tendrils during[Read More…]
A group of samples of several varieties of blue holly (Ilex x meservae) arrived in the lab from a commercial nursery in late January with a common problem, yellowing and rapidly dropping leaves and general poor growth (Fig. 1). After ruling out disease and insects on the foliage we next checked the root systems. After[Read More…]
Dandelion (Taraxacum officinale) Family: Asteraceae Life cycle: Perennial Reproduces: Seed Flowers: 1-2” diameter yellow disk and ray flowers on long stalk. Leaves: Simple, lobed (variable), wavy margins (variable), 3-10” long originating from a basal rosette Seedlings: Dicotyledon that is smooth, yellow-green and lack hairs. Comments: A very prominent tap root that can vegetatively[Read More…]
Purdue’s Plant and Pest Diagnostic Lab (PPDL) receives more than 2000 samples for diagnosis each year. We’ll highlight some of the more interesting cases in the Purdue Landscape Report in brief case studies like this. PPDL Case Study #1: White Fungi on Crabapple Branch Earlier this year a landscaper submitted several photos of a crabapple[Read More…]
It’s that time of the year. Starting in the southern portions of the state and gradually moving north, trees, shrubs, and flowers are beginning to break bud, showing the flowers that have been protected all winter long. One of the first trees that you will notice, increasingly out of place more each year, is callery[Read More…]
Winter of 2017-18 was pretty harsh compared to most years. Much of central and northern Indiana experienced 13 or more days well below 0º F, while southern Indiana had 4- 5 days just a few degrees below 0º F. In addition, gusty winds contributed to further injury by desiccation of buds and twigs. The consequences[Read More…]
There may still be time to protect Prunus spp. from Taphrina leaf curl. Do you remember seeing red, curled, distorted, leaves on Prunus spp. last year and wondering what might have caused this symptom? Taphrina leaf curl, a fungal disease that survives in bark and bud scales, infects peaches and nectarines as well as ornamental[Read More…]
Spring provides a great opportunity to kill insects that winter in vulnerable stages on leafless twigs, or on last year’s hardened off evergreen leaves or needles. The absence of tender leaf tissue makes it possible to use higher concentrations of oil that can kill insects without harming the plant. Dormant oil applications can have the[Read More…]
Although late winter is generally the ideal time for pruning chores, many of our spring-blooming shrubs are best pruned immediately after flowers have faded. Trees and shrubs that bloom in early spring, such as forsythia, lilac, honeysuckle, quince and spirea, set their flower buds the previous fall, referred to as “flowering on old wood”. If[Read More…]
Colorado blue spruce is not native to Indiana (no spruce is!), and it often suffers from environmental stresses such as drought, excessive heat, humidity, and compacted or heavy clay soils—making it an already poor choice for our landscape. If that weren’t enough, it also suffers from needle cast diseases. Needle cast is a generic term[Read More…]
Fill in the blank: Apply crabgrass preemergence herbicide when____________is in bloom. If you said forsythia, you would be correct. Most of us have been told the answer to this for many years, but have you ever thought to yourself, ‘Is it true?’ There are many ways that people make decisions on when to apply herbicides. [Read More…]
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