Soils Are Cooling – That’s Good and Bad

Recently, surface soil temperatures have been dropping below 70° F at night. While this is a good temperature range for growth of cool season grasses, it is a signal that much cooler soils are not far away. Grow of new seedings, overseedings, and turfs needing recovery will slow dramatically once soil temperatures break below the 60° F threshold. We have reached the time (October 1) where we no longer recommend seeding of most grasses except perennial ryegrass. Perennial ryegrass can be seeded as late as October 15 and still have high probability of develop a stand of turf.

If you need more growth out of your turf, this means there is little the time for action. Waiting another two weeks could be too late for any substantial growth through the rest of this year. In New Brunswick, the rain total for September has been very modest (1.23 inches) and there may be a need to irrigate to get recovery or better establishment of seedings before it is too cool.

Fertilization is another factor to evaluate. A turf that is healthy and vigorous probably doesn’t need fertilization but a thinning stand of grass with a sickly yellow-green color is likely to need some nitrogen fertilization. You need to soil test to figure out whether other nutrients such as phosphate and potash are needed.

Now is a good time to fertilize if the turf conditions warrant it. An application of 0.5 to 0.9 lb. of nitrogen per 1,000 sq. ft. is probably all that is needed for many turfs at this time of year. If the turf continues to struggle nutritionally (sickly yellow-green color), another application of 0.5 to 0.9 lb. of nitrogen per 1,000 sq. ft toward the end of October would be useful. At high rates (above 0.7 lb. of N), use a fertilizer product that contains slowly available nitrogen. Note that state law requires lawn fertilizers sold at retail (to homeowners) to contain slow release nitrogen. Also recall that state law prohibits nitrogen and phosphate fertilization by homeowners after November 15. Professional are prohibited from N and P fertilization after December 1.

Cool weather is about to limit the establishment of new seedings. In this photo, poor seed to soil contact will also inhibit the establishment of new turf.

Cool weather is about to limit the establishment of new seedings. In this photo, poor seed to soil contact will also inhibit the establishment of new turf.

 

The 2014 Rutgers Turfgrass Research Field Days Sets Attendance Record!!

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.

Localized Drought Stress is 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.

Symptoms of subtle wilt stress on June 22. Healthy turf will likely to tolerate this level of wilt stress.

Symptoms of subtle wilt stress on June 22. Healthy turf will likely to tolerate this level of wilt stress.

 

 

 

 

 

 

Grasses such as the fine fescues and annual bluegrass will be [Read more...]

Crabgrass Emerging

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.

Relatively small crabgrass plants  (most pre-tillering stage) emerging from a footpath on June 11th.

Relatively small crabgrass plants (most pre-tillering stage) emerging from a footpath on June 11th.

 

Management options for this weed at this point in the season range from doing nothing to [Read more...]

Tis the Season for Summer Stress

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...]

Right On Cue: Dollar Spot Disease

Exactly like Dr. Bruce Clarke teaches, Memorial Day arrives and so does dollar spot disease.

Symptoms appear as round, brown to straw-colored spots approximately the size of a silver dollar. On short cut turf, the spots with advanced damage can become somewhat sunken. At taller cutting heights (greater than 1 inch), the damaged spots are larger and more diffuse.

Highly susceptible grasses will be the first to exhibit symptoms including annual bluegrass, creeping bentgrass (depending on cultivar), and perennial ryegrass. Tall fescue and most Kentucky bluegrasses will be more tolerant of this disease.

Cultural techniques that can suppress dollar spot disease include disruption of dew and guttation water in the morning and increasing N fertility (if it is low). Mowing early in the morning (disruption of dew) should also be helpful.

Creeping bentgrass entries in Dr. Stacy Bonos' evaluation trials that are highly susceptible to dollar spot disease appear in the image foreground.

Creeping bentgrass entries in one of Dr. Stacy Bonos’ evaluation trials that are highly susceptible to dollar spot disease (image foreground).

Update: Green-up of Turf

Most landscape lawns, sports turfs, and golf course surfaces should have reached full green-up but there will be some exceptions. The major exception to this is zoysiagrass turf. Zoysiagrass will not begin green-up until mid- to late-May. Although not as slow to green-up as zoysiagrass, fine fescue will be slower than perennial ryegrass and tall fescue. Many of the Kentucky bluegrass varieties that are commonly used for sod production will be slow to green-up in the spring.

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Dormant zoysiagrass with patches of perennial ryegrass in a home lawn.

 

 

 

 

 

 

 

Lawns that are predominately fine fescue lawn should not be aggressively fertilized with nitrogen; do not apply more than 0.5 lb. of N per 1,000 sq. ft. unless the fertilizer contains 30% or more slow release nitrogen. Even with slow release N, applications to fine fescue should not exceed the 0.75 to 0.9 lb per 1000 square feet range during the spring. Over-fertilizing fine fescues could lead to serious summer stress problems including poor heat and drought tolerance.

A predominately hard fescue lawn that has not reached full green-up in late April. Avoid overfertilizing fine fescues to force green-up. Serious summer stress problems could develop.

A predominately hard fescue lawn that has not reached full green-up in late April. Avoid over-fertilizing fine fescues to force green-up. Serious summer stress problems could develop.

Slow green-up of Kentucky bluegrass can be overcome to some extent with N fertilization. Fertilization in the spring will not cause the same summer stress problems with Kentucky bluegrass compared to fine fescues. But care should be taken to avoid over-fertilization. Over-fertilization problems on Kentucky bluegrass are more likely to be evident over multiple growing seasons rather than a single season. Excessive thatch build-up is the major problem of over-fertilizing Kentucky bluegrass, which typically expresses as a severely drought-sensitive turf (roots are growing in thatch, not soil). The total amount of N applied to Kentucky bluegrass during the spring should be within the range of 0.5 to 1.9 lbs. per 1000 square feet. Application rates above 0.7 lb. per 1000 square feet should include slow release nitrogen to limit surge growth and protect against N leaching.

Rectangular plots with a tinge of tan-color are varieties of Kentucky bluegrass exhibiting slow spring green-up (photo taken 18 Apr. 2014).

Rectangular plots with a tinge of tan-color are varieties of Kentucky bluegrass exhibiting slow spring green-up (photo taken 18 Apr. 2014).

 

 

 

 

 

Brown Ring Patch Spotted in New Jersey

Brown Ring Patch (aka Waitea patch) is starting to show up on golf course putting greens at this time.  This disease is caused by the fungus Rhizoctonia circinata var circinata and typically develops during warm weather from April through June.  Symptoms start as small yellow rings (0.25-2 inches wide) with green grass in the center and can ultimately reach a foot or more in diameter. The yellow rings can turn an orange or brown color as the disease progresses.  Although the disease rarely kills turf, affected areas are extremely slow to heal.  For best results, apply Medallion, polyoxin-D (e.g., Affirm or Endorse), ProStar, one of the QoI fungicides (e.g., Heritage or Insignia), Trinity, Triton Flo, or Torque now and repeat in two to three weeks to limit disease development later this spring.   Unlike yellow patch, the brown ring patch fungus can degrade the thatch in infected areas so several fungicide applications are typically required to prevent significant damage.  Seedhead suppressants (e.g., Proxy + Primo) may enhance disease severity.  Therefore, be sure to initiate a preventive brown ring spot fungicide program in areas where this disease has been troublesome and seedhead suppressants have been applied.  For more information on brown ring patch, click here.

Brown ring patch on a golf green (Photo courtesy of S. McDonald)

Brown ring patch on a golf green (Photo courtesy of S. McDonald)

 

Leaf Spot and Melting-Out is Active

Leaf Spot of Kentucky bluegrass.

Leaf Spot of Kentucky bluegrass.

The leaf spot phase of this disease, caused by the fungus Drechslera poae, is apparent on susceptible Kentucky bluegrass turf at this time.

Melting-Out of Kentucky bluegrass.  A resistant cultivar (left) compared to a susceptible cultivar (right).

Melting-Out of Kentucky bluegrass. A resistant cultivar (left) compared to a susceptible cultivar (right).

To prevent severe damage from the melting-out stage of this disease during the next six weeks, avoid heavy applications of nitrogen in the spring (not more than 0.5 lb N / 1,000 sq. ft. / application of quick-release, water soluble formulations such as urea or ammonium nitrate), maintain the cutting height at or above 2 to 2-1/2 inches, remove excess thatch, and apply Armada, Compass, Disarm, Headway, Heritage, Insignia, mancozeb, Medallion, Tartan, or Velista now, per manufacturer’s recommendations.  Avoid the use of certain acropetal penetrant fungicides (e.g., benzimidazoles) this spring in areas with a history of leaf spot and melting-out, since these fungicides may intensify symptom expression.

The Rutgers Golf Classic is Almost Here!

The Rutgers Golf Classic will be held on May 5, 2014 at the Fiddlers Elbow CC in Bedminster Township, NJ.  This is a major regional turf research fundraiser that has attracted golfers from eight states and has raised over $1.3 million for the Rutgers Turf Research Program over the past 18 years.  To be a part of this great opportunity to support turf research and extension programs at Rutgers, access on-line registration information at www.njturfgrass.org or call the New Jersey Turfgrass Foundation at (973)-812-6467.