Crabgrass

Large crabgrass (Digitaria sanguinal)

Crabgrass is the bane of many people seeking a ‘nice’ lawn. It is a weedy grass which will out-compete desirable grass species and take over in a short time. Crabgrass has a wider blade, is lighter in color and grows faster than the lawn making it obviously stand out as a weed. Its seed germinates earlier and at lower ground temperatures than other desirable turfgrasses giving it a jump in growing time.

The best defense against all weeds of lawns is to maintain a healthy stand of turfgrass by having soil pH and nutrients at the correct levels. Healthy soil supports healthy grass. Lawns mowed at a height of three inches or taller has less crabgrass and other weeds as the soil it shaded, excluding light from reaching the seeds which initiates germination. Crabgrass is an annual growing new plants from seed each year. None of last year’s crabgrass lived through the winter.

Low cut grass invaded by crabgrass.

 

 

Chemical control against crabgrass is applying a pre-emergent herbicide. They attack the newly produced tissue from the germinating seed up to young plants with a couple of leaves. Pre-emergent herbicides have no effect on seeds in the soil that do not break dormancy and start to grow, only the seeds which start to grow. Timing of application is before the crabgrass seeds start to germinate when to the soil temperatures are 50 to 55 degrees Fahrenheit. This is the same time the forsythia is just past its full bloom stage and starting to but out some green leaves.  The germination period ends when the lilacs begin to bloom. Just remember to apply after forsythia and before lilac flowers. Forsythia and lilac make a great plant indicator for applying the pre-emergent herbicide against crabgrass.

Forsythia bush.

Lilac, photo (psu.edu/lilac)

There are several different pre-emergent herbicide active ingredients with varying rates of how long they last in the soil. Products containing pendimethalin will last about four months out in the environment. Other active ingredients, dithiopyr, benefin+trifluralin, prodiamine, will last a shorter period of time. Read the labels for the residual rate for each formulation’s time it will last. Most pre-emergent herbicides will stop all seeds from continuing to grow after germinating. This means you will not be able to plant desirable grass seed after applying it. Products containing Siduron are the only pre-emergent herbicide that will allow cool season grass seeds to grow while eliminating crabgrass.

-Carol Quish

 

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What We Do At The UConn Home and Garden Center

The UConn Home and Garden Education Center offers information on all things horticulture. Our mission is to give the public answers to their plant and insect related questions by our well-trained horticulturists and staff via phone calls, emails and in person. We provide outreach from UConn to the citizens of the State of Connecticut and many other states, through the Cooperative Extension System and the Plant Science and Landscape Architecture Department. We may be contacted at:

UConn Home and Garden Education Center

Room 4, 1380 Storrs Road

Storrs, CT 06269-4115

 

877-486-6271

 

Ladybug@uconn.edu

 

 

Powdery Mildew on Squash Leaves, C.Quish photo

Milkweed Beetle, C.Quish photo

We diagnose plant diseases and identify insects, and solve plant problems. Samples of plant material and insects can be mailed or brought to our office located in Storrs on the UConn campus. If a physical sample is received, there is a lab fee of $15.00. There is no charge for emails, phone calls and advice. All of us truly love our jobs, and could (and do) talk about plants all day long!

IPhone and IPad App –  The UConn Home and Garden Education Center’s Plant Diagnostic Lab in conjunction with Purdue University, has developed an IPhone and IPad App for folks to submit photos of plant problems.If you don’t have an IPhone, email us directly. All submissions may include plant disease or insect problems, and plant or insect ID. It is a free service and free to download. To find the app, search for ‘plant diagnostic sample submission’ at the app store. https://itunes.apple.com/us/app/plant-diagnostic-sample-submission/id669269520?mt=8

When we are not busy helping people, we write about gardening to keep you informed. New research and current happenings in the environment will be made known to the public through our many ways getting the news out. Several of us develop and present talks to garden clubs and other groups around the state. Some also lecture in the The UConn Master Composter Program and the UConn Extension Master Gardener Program. We have a booth at the CT Flower and Garden Show in Hartford during the month of February each year.

 

UConnLadybug Blog – If you are reading this, you already know we have a weekly blog! Our well-versed group of five take turns writing about gardening, plants, pest, insects, birds and just about anything we think might interest our nature centered audience. We each have a little bit different style to enlighten and educate. https://uconnladybug.wordpress.com/

 

Home and Garden Newsletter Subscription

 

Home and Garden Newsletter – A quarterly paper newsletter mailed to you home contains timely and accurate information from faculty and staff throughout the college and eight Extension Centers who contribute their knowledge and expertise on a wide variety of issues such as entomology, food safety, drinking water, soil testing, home horticulture, lead poisoning, indoor air quality, septic system management and family financial management. Cost is $10.00 per year. http://www.ladybug.uconn.edu/newsletter/index.html

 

E-Update monthly newsletter – Dawn Pettinelli, our manager, scours the internet for science based, university researched and accurate articles and tidbits of timely information, to gather all that knowledge in one place which is then sent out through our listserv to those wishing to receive it. She also includes what is happening in the landscape during that particular month. It is informative and comforting to know others may be having the same problems and how to handle them. If you wish to have your email added to our Listserv, send an email request to Ladybug@uconn.edu.

Soil Testing in Process

UConn Soil Nutrient Analysis Laboratory – Have soil tested for pH and nutrient levels, lead screening, organic matter content and soil texture by visiting  UConn Soil Testing Lab Their goal is to increase the public’s awareness of the benefits of soil testing and the necessity of environmentally sound soil fertility management programs. The lab also functions as a teaching resource where CANR graduate students learn to run their samples on sophisticated equipment and as a base for numerous outreach activities.

 

Facebook – We are on facebook as UConn Home and Garden Education Center. Please Like us to see great photos and more current happenings in the natural world around us.

Website – Last, but not least, we have a website. Our fact sheets are located here,  as is a lot of other information. We are the midst of creating a new one, but are leaving the original in place until the new website is unveiled. http://www.ladybug.uconn.edu/index.html

 

-Carol Quish

 

A Little Bit About Beetles

Pest – Colorado Potato Beetle Adult, http://www.uwm.edu

Pest – Colorado potato beetle larvae, http://www.agriculture.purdue.edu larvae

Beetles are fascinating insects with a wide variety of colorful families and species. Some are beneficial, feeding on other insect, while other species are just plain pests. All beetles are in the order Coleoptera. Common among all adult beetles are two pair of wings, with front wings being thickened and leathery that completely cover the membranous hind wings. Adults have large compound eyes and chewing mouth parts.

Beneficial Predator as Adult – Eyed click beetle Photo by Pamm Cooper

Pest – Wireworms, maine.gov

 

Beetles have complete metamorphosis containing four life stages; egg, larva, pupa and adult beetle. Larvae have chewing mouth parts, and simple eyes which detect light, dark and movement, but cannot see as well as adult stage with the compound eyes. Different species of beetles differ in larval form. Some are c-shaped grubs with six legs, and others are wireworms with no legs. The common grubs found in the lawns will develop into beetles.

Pest – Japanese Beetle umass.edu

Pest – Japanese Beetle Adult

Control of all beetles can be achieved by hand picking adults and larval stages. Grubs in turfgrass are treated when grubs are newly hatched during the end of May through July by using Imidacloprid or Chlorotraniliprole as the active ingredient. Parasitic nematodes can be applied to lawns to infect the grubs, eating their insides so they never develop into adult beetles. Milky spore is a bacterial disease that affects only Japanese beetle grubs, although it has limited efficacy here in Connecticut.

In the vegetable garden, monitor known host plants by turning over leaves to look for eggs to crush them by hand. Insecticidal soap sprayed directly on any larvae will kill them by suffocation. Spinosad is an organic insecticide that will kill larval stages, too. Monitor for natural predators that would keep the pest population under control. Using broad spectrum insecticides will kill the good guys as well as the pests.

Carabid beetle Lebia grandis are voracious predators of Colorado potato beetle eggs and larvae. photo by Peggy Greb, extension.psu.edu

Colorado Potato Beetle Eggs, umass.edu

 

-Carol Quish

 

 

 

 

Ground Ivy and Orange Growths on Cedar Trees

Weeds are making a fast and bold appearance in lawns and gardens this week. I am seeing strong growth of ground ivy, (Glechoma hederacea). Ground Ivy is a perennial weed commonly found in turf. It  spreads by creeping rhizomes, rooting at  the nodes to produce new plants. The purple flowers produce seeds, another way for the plant to spread. Hand pulling is one way to eradicate this creeping vine, but not very effective as the vines break where the nodes are rooting in new spots. It tends to creep through the grass lower than the blades of the lawn mower, thereby not controlled by regular mowings. I find it mostly on the fringes of the lawn, reaching into the flower and vegetable gardens. The best way to kill it is to use a broad leaf weed killer containing 2,4-D or triclopyr. This plant will need more than one application to completely rid the lawn of plants present. New plants will be created from germinating seeds throughout the season. Watch for new invasions and treat accordingly. A pre-emergent herbicide can be used to stop the germination of seeds.

Figure 1: Juniper branch with a mature Cedar-Apple Rust gall displaying gelatinous tendrils. (provided by Dr. George Hudler, Cornell University)C

Figure 4: Juniper with Cedar-Apple Rust displaying a developing gall---the winter survival structure. (provided by Dr. George Hudler, Cornell University)

Cedar Apple Rust fruiting structures are appearing on the branches of cedar and juniper trees this week. They look like an orange sticky sea creature shocking people not familiar with this fungal disease. Cedar-apple rust is caused by the fungus Gymnosporangium juniperi-virginianae. The orange horned structure grows out of the overwintering hard brown gall after a few days of rain and cool weather. Spores are produced from the structure beginning and mid-summer, becoming air-borne and dispersed by the wind. These spores will land on the alternate host in the Malus or apple family to continue its life cycle. Once an apple or crabapple is infected with the new spores, the fungus develops on the leaves, creating spots and eventually turn the leaves yellow. Early defoliation of the malus tree usually follows.The cedar tree retains the deformed tissue some find unsightly.

Control measures used are planting resistant cultivars of trees, sanitation and fungicide sprays.

Resistant cultivars of apple include Delicious, Empire, Jonamac, McIntosh, and Paulared. Resistant crapapples are Ellwangerina, Henry Kohankie, Ormiston Roy, and Red Baron. Resistant junipers are Juniperus chinensis var. sargentii, J. communis cv. Aureospica, and J. virginiana cv. Tripartita.

Sanitation measures reduce the incidence of infection. Cut off all orange and brown growths on the cedar trees. Do not put these in the compost or them might continue to release spores even after being cut.  Bag them for disposal in the the trash. This one action will reduce the amount of spores released in the air. Remove either host trees for up to one mile, although this usually not possible! Fungicide options are available for the apple and crabapple trees, used as a preventative measure before the spores land on the leaves. Fungicide used on the cedar and juniper are not very effective. Rake and remove to the trash any fallen leaves of the apple species. The fungus can overwinter on the leaves to keep the disease cycle going into the next spring.

Fungicide labeled for use on apple and crabapple in Connecticut are chlorothalonil, mancozeb, triadimefon, propiconazole, and myclobutanil. Sulfur can be used as an organic fungicide option. Thorough coverage of all leaves are needed for protection. Follow all label directions, more than one application may be necessary for season long control.

cedar-apple rust on apple leaf

-Carol