Biology: Broadleaf plantain (Plantago major) is a perennial, broadleaf weed that can be found in nutrient-poor soils; however, they prefer nutrient rich-soils that are moist and often high in calcium. Broadleaf plantain is a common weed in turfgrass, nurseries, and landscapes. It germinates from seed in late spring through mid-to-late summer and occasionally in the fall depending on temperature and moisture. It has a low growing rosette habit and tolerates close mowi ng. It’s ability to survive a range of environments make broadleaf plantain a common weed in North America. Identification: Broadleaf plantain is anchored primarily by fibrous roots. Some describe the root system as having a central, short taproot with branched-out fibrous roots but my experience is that large, fibrous roots are common and that taproots (especially large taproots like a dandelion) are very uncommon. Broadleaf plantain grows with a rosette habit with leaves that can grow flat along the[Read More…]
Archives for May 2018
Arborvitae varieties (Thuja spp.) provide some of our most beautiful and versatile evergreens for landscapes, with an extensive selection of sizes and types. Unless they get proper care, they also give us some frustrating failures. Here is my list of the most frequently encountered ‘Arborvitae Aggravations’, based on the samples and questions we get in the PPDL; in no particular order. Transplant stress: Transplant stress is a normal result of planting or moving any tree or large shrub but it is frequently more serious for conifers like arborvitae. If the plant has dried out at any point before transplant the stress and browning of foliage will be much worse. Don’t keep root systems soggy wet but do make sure they stay evenly moist until planting. During the first summer be especially vigilant about watering. Keep soil evenly moist and make sure water penetrates into the full root zone. After establishment[Read More…]
Some landscape plants produce vigorous, upright stems that become troublesome as they out compete better-formed branches and shade out the rest of the plant. These remarkably fast growing, upright stems are called “suckers” if they come from the root system, and “watersprouts” if they originate from other stems. Ornamental crabapples are among the most notorious producers of these unwanted stems, but many other trees and shrubs can be afflicted, including contorted filbert, peach, apple and dogwood. While there are a few landscape plants that are supposed to have very upright habits, in most plants, this upright growth results in a weak architecture in addition to causing overcrowding. Limbs with narrow branch angles are more prone to internal decay and breakage during storms. Both suckers and watersprouts can and should be removed any time they occur though it is often easier to see their architecture during the dormant season. The earlier[Read More…]
On May 2nd an apartment fire in Greenwood occurred that reportedly originated in the mulched landscape beds. Unfortunately 56 renters were displaced that day, but fortunately no injuries were reported. Several Indianapolis news organizations reported on the origins of the fire that included a couple of quotes that were not entirely accurate. One of those interviewed stated that the most likely cause of the mulch catching fire was due to a cigarette being discarded, which happens quite often during dry periods and is correct. The quote that stood out was, ‘The mulch itself can decompress over time, decompose, and that decomposition can cause a chemical reaction that can actually cause the mulch to catch on fire by itself.’ This statement, taken at face value, can make sense to some folks. Think about wet hay catching on fire in a barn, or the mulch fire that occurred in Southern Indiana[Read More…]
Spotted lanternfly is a nasty new pest that may soon be in Indiana. It weakens a wide variety of trees, covers them with mold and threatens fruit and grape growers.
For more information about the Purdue Turf and Landscape Field Day Turf and Landscape Field Day
Boxwood leafminer damage is widespread. It’s not too late to protect boxwoods from boxwood leafminer and protect pollinators.
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!), causing spots and blights on leaves and stems (Fig. 1). The strain Xanthomonas axonopodis pv.begonia (formerly known as X. campestris pv. begonia) is specific to begonias, and does not readily spread to other plant genera. The abbreviation ‘pv.’ is short for ‘pathovar’, which is defined as a bacterial strain that is distinguished from other Xanthomonas axonopodis strains based upon the host plant it is pathogenic to). Begonias of all species are vulnerable to this pathovar, along with creeping saxifrage (Saxifrage stolonifera). On many crops the disease cycle of Xanthomonas spp. often begins with contaminated seeds, but outbreaks in begonia[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 as small spots on the leaves (Fig. 1) or flowers (Fig. 2) or may cause stem collapse (Fig. 3). Under favorable conditions blighting can be extensive and give the appearance that the plant has been burned, hence the name tulip fire (Fig. 4). There are dozens of species of Botrytis which attack thousands of types of plants but B. tulipae has a particular affinity for tulips and is found around the world. When Botrytis infections kill whole leaves the outer bulb scales and roots of the plant may become infected. The fungus then forms small[Read More…]