Warm air temperatures build anticipation of plant growth but keep in mind that cool soil temperatures will strongly moderate growth during the spring. Turf growth typically will be very slow until [Read more…]
The weather this summer has been very conducive for brown patch and Pythium blight diseases. I have received number requests this summer to address turf problems related to one or both of these diseases in lawns, sports fields, sod and now my own plots.
The weather forecast for the rest of this week indicates [Read more…]
Daily high soil temperatures at the 2-inch depth are consistently getting into the 60s °F. Yesterday, temperatures in sunny locations reached into the upper 60s. This means that the warm-season species are, or will be soon waking from winter slumber.
For the last three weeks, I have been watching the emergence of false green kyllinga (Kyllinga gracillima). Most sites infested with kyllinga are probably showing active shoot growth. So it appears that kyllinga needs soil temperatures that reach consistently into the 60s to emerge from winter dormancy. As temperatures continue to warm, re-growth of kyllinga should accelerate.
False green kyllinga is a perennial sedge species with well-developed rhizomes (underground lateral spreading stems). Kyllinga is relatively low growing so it [Read more…]
Other than today and yesterday, soil temperatures in New Brunswick have been reaching into the lower 50s °F during the last week or so. And you see the effects, some plants are finally awakening from winter slumber. Cool-season turfgrasses are slowly greening up. Tree buds are swelling, some are flowering. Forsythia is just starting to bloom. And prostrate knotweed, one of the earliest germinating summer annual weeds, is emerging.
Prostrate knotweed is frequently found invading [Read more…]
We lost the ice cover on our Poa annua trials two weekends ago (March 7-8th) and initially the turf looked okay. But now… it doesn’t. And it will probably get worse, if we are reading the symptoms correctly.
Last Friday (March 13), my graduate student, Chas Schmid, informed me that I needed to look at his potassium trial on our Poa annua turf. There was a huge difference between no-K and K fertilized plots. The no-K plots have steadily lost green color and become very blotchy. Plants taken from those plots are water-soaked and feel mushy when squeezed (How is that for a scientific description?). Dr. Lindsey Hoffman has a lot of experience with winterkill on Poa annua in Massachusetts and she is convinced that many of the plants are dead. And it smells like it – silage on a dairy farm!
Take home for me – don’t let your Poa annua turf become potassium deficient! Chas’ data for suppressing anthracnose severity indicates that a soil test (Mehlich 3) ≥50 ppm K and a tissue level of ≥2% K in the clippings are indicators that the K level is good. And winterkill in March 2015 hasn’t changed my mind about that data!
Looks like this might be the end of this Poa annua field. Dr. William Meyer said, “Good riddance.”
Damage to landscapes from traffic can be severe during winter and especially now during the thaw. Soil conditions currently range from being frozen to partially thawed/frozen to thawed.
Partially frozen soil will be thawed and very wet at the surface while being frozen at some depth below. Under this condition, soil and turf will be extremely vulnerable to shearing and rutting damage. Traffic, even light foot traffic, must be withheld when this condition exists otherwise severe rutting (soil displacement) will occur.
Soil temperature has been “stuck” at freezing for some time now. Today is the first time this year that I have noticed the 2-inch deep bare soil temperature was above 33 °F (> 35 °F at the time of writing this post) at the New Brunswick Rutgers Gardens weather station. Interestingly, the 2-inch soil temperature under sod at this station remains only tenths of a degree above 32 °F, illustrating the insulating effect that vegetative cover has on soil.
Keep in mind that just because a soil has thawed doesn’t mean it is out of danger from traffic. At this time of year, soil will be very loose from frost heaving and very wet or saturated. Soil on very well drained sites will firm up sooner than poorly drained sites but all sites will be very susceptible to damage from traffic for some time after a thaw. Care should be taken to avoid traffic of any kind when the soil and turf is vulnerable.
Allow soil to thaw completely and drain to at least field capacity (preferably drier) before allowing traffic on the landscape. Draining and drying will help to re-settle areas that frost heaved. Light-weight rolling may be need on soil that experienced extensive frost heaving and remains too loose after draining and drying.
The annual event, held on July 29-30, highlighted ongoing turfgrass research at Rutgers and was attended by over 800 industry professionals! Read the full story here.
As stated in an early post, summer stress is developing throughout the state. Summer stress isn’t widespread or severe but it is developing, particularly wilt stress, within very localized areas of many landscapes. Landscapes that receive little to no irrigation are especially prone to wilt and drought stress right now.
It is important to scout and assess the severity of any wilt stress in moderate-to-high value areas of the landscape. Hours are important, don’t put off the scouting of wilt stress. Assuming the grass or other plants will tolerate wilt stress without confirming the severity of the situation can lead to severe drought stress and stand loss at this time of year.
Grasses such as the fine fescues and annual bluegrass will be [Read more…]
Crabgrass has been emerging for several weeks now, depending on the exposure. Warmer and more open turfs will likely have more advanced (larger) plants while cooler and denser turfs will have smaller plants.
Management options for this weed at this point in the season range from doing nothing to [Read more…]
Optimum growth of cool season grasses occurs within the temperature range of 60 to 75 °F. Yesterday, the New Brunswick weather station indicated that soil temperature at 2 inches exceeded 75 °F for more than 12 hours and peaked at 82 °F.
This doesn’t mean that grasses will soon be dead. But it is a signal to be watchful for summer stress problems.
Summer stress is often a combination of multiple stresses. Localized drought, ponding of water, diseases, insect pests, poor culture (mowing, fertilization, and irrigation) and other stresses combined with high temperature stress can challenge the health and persistence of cool season turfs from now through the end of summer. It is important to avoid situations that compound too many stress at the same time.
For example, now is the time [Read more…]