Crabgrass Management Starts Now

Crabgrass is a pesky annual grassy weed that loves irrigated lawns here in the Central Valley. It gets really large and very apparent in lawns by mid-summer, but by then it is much more difficult to control. Left unchecked, crabgrass can rapidly take over a nice lawn in a matter of a few years.

Here’s the problem.  You will not find an effective product for controlling existing crabgrass or dallisgrass on your store or nursery shelf.  MSMA, found in Weed Hoe and Trimec Plus, is no longer available to homeowners and was the only product that actually worked on the removal of unwanted crabgrass unlike the products offered now.  There are several products now on the market for homeowners for post-control of crabgrass and they all contain quinclorac.  I have not had good success at all in the Central Valley of California getting any significant control using these.  Maybe you will be lucky and make one of them work, but my guess is that they won’t and you will be out both the time and expense you have invested. 

Prevention is the key to crabgrass management especially without a reliable product for managing actively growing crabgrass plants.  Ideally, a pre emergent herbicide should be applied at the proper rate prior to Valentine’s Day.  There are a number of products out there (some better), but unless they are applied before seed germination at the right rate and uniformly the results could be less than desirable. We actually apply two applications to ensure better results.

What is the future for crabgrass control?  There are some products in development and a few that could be useful in certain cases.  There is a product called Tenacity that has some decent early post emergent control of crabgrass, but it is only recommended for cool season turf as Bermuda will turn temporarily white following application.  Other herbicides have also shown some respectable control of 1 to 2 leaf crabgrass (tiny) as well.  A sharp knife works well, too unless you have hundreds or thousands of plants. 

Why risk your lawn to crabgrass invasion when the cheapest and most effective solution is prevention with pre emergent herbicides.  Have your lawn treated either by yourself or a professional today.

New Year’s Resolution – “I Will Treat My Lawn Nicely”

Lawns are often taken for granted or even neglected and certainly don’t make most people’s resolution list.  I think it is time to change that and start by spreading a little wealth and effort in the direction of one’s lawn and landscape.  The lawn, trees, shrubs, and flowers are a vital part of the home and they certainly add to the value of the property.  Industry experts say a nice landscape can add 15% to the value of a home and for most of us with a home, it is the largest asset we have.  The experts did not say how much an unattractive landscape impacts the home’s value, but you can be sure it is not positive.

What can be done to have a better lawn and landscape in 2013? First I would recommend taking inventory on the current condition of the yard.  That would mean checking the sprinkler system, the shading/sunlight and exposure, the soil condition and drainage, etc.  Landscapes change over time.  The wonderful hybrid bermuda lawn you had 10 years ago may now be only a thin, spotty stand now due to heavy shade conditions as a result of your trees growing up.  The great sprinkler coverage you once had may now be compromised due to plants covering heads, dirty nozzles, or reduced water volume or pressure.  Many times it was never that good in the first place.

Assuming that you now have conditions suitable to grow healthy lawns and plants you are ready to attend to their needs.  Like you and I, they need to be fed regularly.  Proper nutrition helps them grow at a healthy rate and compete with pesky weeds, diseases, and insects competing for their space.  Proper mowing heights and regular mowing encourage a dense turf that can better compete with invasive weeds.  Some weeds like crabgrass and spurge can forge their way into most any lawn; good or bad.  Pre emergent products should be applied starting in February in order to keep them out.  Other weeds like invasive bermudagrass and nutsedge need to be dealt with on an individual basis. 

By the way, did you know that homeowners no longer have access to any products that work well for the removal of existing crabgrass or dallisgrass since the removal of MSMA products like Weed Hoe in 2012?  This year, 2013, is the last year that professionals can use MSMA so PREVENTION is the word from now on….period.

You need to decide if your lawn and landscape is important to you.  It cannot take care of itself.   If you want good results without all the hassles then call a professional that knows what they are doing.

Should You Leave the Leaves Alone?

It looks like summer finally gave way to fall and the leaves are really dropping.  Leaves end up everywhere including the roof, gutters, walks, flower beds, and the lawn.  In some cases they can get pretty thick depending on the surrounding trees.

The question is what is the proper thing to do with all those leaves?  Are they beneficial or harmful? It depends. The leaves are a good source of carbon and can help enrich soils as they break down and feed all the little soil microbes.   When the accumulated leaves reach a point where the lawn or flowers are completely buried, or worse yet, wet and matted, then you risk thinning and damaging the plants below.  Extended periods of low or no light will result in yellow, thin, and elongated leaves.  You see, they need light to carry out photosynthesis and make green chlorophyll.

How should you manage the leaves then?  I would suggest that leaves be allowed to accumulate and decay in flower beds if you are okay with the look.  It can help build healthier soils, reduce weeds, and retain soil moisture.  Green plant material should not remain covered for more than a week and perhaps shorter in the case of wet, matted, leaves.  For cool-season lawns that do not go dormant, I would recommend mulching the leaves into the lawn with a mulching mower when the lawn and leaves are dry enough to do so.  If the leaves are too thick, they may need to be raked off.  Another solution during leaf fall is to mow more frequently to allow the mulching mower to effectively mow the grass and leaves without leaving piles of debris.  If clippings pile up during the mowing process the accumulated clippings could be mowed again, raked, or blown, to distribute the piles and keep the turf healthy.  Dormant lawns should have the leaves mulched in or raked off during the winter prior to spring green up.

While leaves can be good for soils, they must be managed.  Do not let them form a dense mat on desirable plant material like flowers or lawns as they can cause thinning, yellow leaves in lawns and flowers.  Removal or mulching are your best two options and must be done regularly during heavy periods of leaf drop.

Winter Fertilization of Lawns

Pink Snow Mold

People often choose tall fescue over bermuda lawns as they want a year-round green lawn.  There is no great advantage to having a tall fescue lawn in the winter that looks anemic at best due to neglect.  People want green.  Lawns will battle cold soil temperatures, saturated soils, extended damp and foggy periods, frost, and occasional diseases like rust and pink snow mold.  This is not exactly hitting tall fescue’s sweet spot of sunny, 65-75 degree days seen in the spring and fall. 

If no fall fertilization occurs then the likelihood of having a green lawn in January and February is dismal.  Tall fescue lawns need a bit of a push heading into the cold weather.  It needs to be pushing new growth albeit slow.  No grow…no green.

Can you just put any fertilizer out there in the fall and expect decent color?  You will probably see a response from most any fertilizer, but the level of response in colder weather will change with the source of nitrogen in the fertilizer.  I am a strong proponent of slow-release fertilizers as they are less likely to burn in the summer months and they feed the plants over an extended period of time allowing for greater efficiency and uniform growth.  When it comes to colder weather and cold soils we need to look at products that are either readily available for root uptake or can be converted by microbes to an available form in a reasonable time period.  You may have noted that many of the winter fertilizers have some form of nitrate nitrogen in the blend.  Nitrate is readily available to the plant and will be the form that with yield the fastest response.  Urea and ammonium forms may take 2-10 weeks to be converted to nitrates for plant uptake.  These are normally quick-release products in warm weather, but act like a slow-release in winter months.  I do not see a great benefit to sulfur-coated or poly-coated products at this time of year as they will likely not be available until sometime in February or March.

Healthy Tall Fescue 

How about other nutrients?  I always like to see some phosphorus, potassium, and even sulfur in the mix as well.  They may not add much to the plant color, but they can encourage healthier roots and tougher cells walls to fend off temperature stresses and diseases, and make more nutrients available by lowering the pH, respectively.

From past experience it is difficult to have a perfectly green lawn in the winter months.  Some yellow leaves and occasional pink snow mold or brown patch may show up even with a good fertilizer program.  Doing nothing will likely result in poor color for a few months. On the positive side, a good spring feeding and warmer weather will restore your lawn to a great green in no time.

Is Your Lawn Getting a Little Rusty?

I know there has been a lot of excitement over the Giants winning the World Series, but the fact that some lawns are turning orange really has nothing to do with baseball.  The grass may exhibit some yellow spotting initially, but as the rust advances one will see a reddish-orange powder develop on the leaf surface.  These are the spores of a lawn infecting fungus (Puccinia sp.).  Mowers, shoes and clothing can become a magnet for picking up the rust colored spores as they pass across the infected lawn transferring the spores to other lawns that may be susceptible, especially if there is a bluegrass component to the lawn mix.  If you pass your fingers across the leaf blade you will likely have the orange spores deposited on your skin.  It will not hurt you…really.

The rust colored lawns tells me a few things.  First, there is likely some Kentucky bluegrass in the lawn as that is the most likely grass type to get rust.  Ryegrass and tall fescue may exhibit some rust in rare cases here in Central California.  Secondly, rust indicates that the weather has changed and we are in a period where the days are warm (70 to 75 F) and nights are getting cooler and damper.  Spore germination and infection of the rust fungus into host plants can occur with extended periods of leaf moisture lasting 10-12 hours from dew and/or irrigation.  Other conditions like lack of water, low levels of nitrogen, infrequent mowing, and mowing too short can certainly enhance the presence as well.  Rust was noted on lawns November through June this last year, but the peak occurrence was mid March and the month of April. 

Although it can be very visible and a bit unsightly, the disease rarely causes any notable damage to the lawn.  Application of a fungicide is not usually recommended when proper cultural practices are employed.  I would be sure that the lawn has been adequately fed with a fertilizer that will promote new growth thus allowing the infected leaves to be cut and removed.  Secondly, I would make sure the lawn has sufficient water available to favor good growth and water in the early morning so that the period of wetness does not get extended further into the day.  Finally, I would make sure that the lawn is mowed weekly at 2.5 inches or higher.

Problems with Poa

Poa annua

Perhaps you have seen this invasive “winter grass” invade your lawn and flower beds at home in past years. It is a clumpy, spring-green tuft of grass that first appears in October, continues to grow denser and put out an abundance of seed mid to late winter, and finally disappears as the weather warms up in May and June.  Annual bluegrass, Poa annua, is native to Europe, but now found world-wide.  It can grow 6-8 inches tall and can tolerate mowing heights below 1/8 inch as seen on golf course putting greens.  It has been estimated that Poa can produce as many as 14,000 to 63,000 viable seeds per square foot in a year on a golf course green!  Seeds can remain dormant for a few years, but with regular irrigation, most do not show much of a dormancy period.

So, why is Poa a problem, it is green after all. The biggest problem with Poa annua in the Central Valley is that it is a true annual that will abandon you by early summer in full sun areas because it cannot tolerate the heat.  Germination will start as early as August when soil temperatures start to drop below 70 degrees.  Germination will continue throughout the winter and by December (or before) you will start to see the appearance of the open-panicle seedheads popping up.  By February and March you will see the yellow-green patches with seedheads across the lawn areas and throughout the flower beds.  Two to three months later most of the plants will only be brown tufts scattered about.  Just think about the poor golf course superintendent that has to manage greens that are mowed daily at extremely short heights, excessive summer heat, and golfers trampling over the turf throughout the day.  His job is to keep alive what Poa he has and try to minimize its further spread.

Poa annua flowerhead

So what can be done?  If possible, one should try to limit the spread of Poa by not moving the seeds with mowers from bad turf to good turf.  Mowing when the grass is dry can help somewhat, but certainly washing off the mower between lawns is obvious during periods of seeding.  Secondly, a pre emergent herbicide should be applied mid to late August to reduce the likelihood of seed germination.  One must also consider if the lawn is going to be overseeded or spot-seeded late September or early October.  The pre emergent will possibly cause a poor or weak stand of new seedlings as the herbicide will reduce root development.  There are a few options for selectively controlling Poa annua in existing lawns, but they are not available to homeowners and generally they are specific for either warm or cool season grasses. 

Controlling Poa annua in lawns can be tricky, but it’s a no-brainer to apply a pre emergent now in flower beds to interrupt the life cycle this winter and save you a lot of work pulling weeds this spring.

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Why is My Lawn Brown?

This is not an easy question to answer without first asking a few background questions. If the spots are irregular in shape, and not round, I would start with the sprinkler system.  Do you have automatic sprinklers, manually operated sprinklers, or none of the above?  How often do you water? When do you water?  How long do you water?  Next I would look at the sprinklers while they are running.  Are they operating properly?  Is the spacing allowing head to head coverage?  Are there any shrubs or trees blocking the pattern?  Are the heads level and adjusted to the right height? 

Dry spot from lack of water

A soil probe can take a core sample of the top 4-6 inches and tell you if the soil has adequate water and how deep down the water has traveled.  Ideally, you would see good moisture down 4-6 inches deep.  If you can’t get the probe down below 2-4 inches, the soil is likely water deficient.  A standard 6-8 inch screwdriver can also be an easy tool to probe how far down the soil is moist.  Generally, you should be able to push the screwdriver down 4-6 inches with moderate effort.  Too easy…too wet; too hard…too dry.

Pythium Disease

Brown lawns could also be the result of numerous pests.  Diseases generally cause circular yellow-brown patterns in the lawn and symptoms vary with the pathogen involved.  Insect damage can be somewhat random in appearance.  Some pest attack the roots causing failure of the lawn in patches while others feed on the leaves causing thinning or yellowing.

Lastly, and you may not want to hear this, but there could be several cultural habits that cause a lawn to fail during stress periods.  Over watering or watering frequently, especially in the evenings, could encourage disease activity.  Over fertilizing, especially spilling fertilizer, can cause rapid browning due to the high salt content (like pet urine burns).  Mowing too short, too infrequently, or with dull mower blades can stress the lawn as well.  Ideally they should be mowed at least weekly and at the proper height for that particular grass type.  There are also the odd things like sunlight reflection off a large picture window, placing car floor mats on the lawn while cleaning the car, construction cleanups, and space aliens landing at night. 

Hopefully, you now have some ideas on how to troubleshoot your brown spots, or you can always give us a call for a free analysis.  The weather is going to become cooler shortly and many of this summer’s brown spots will be disappearing for several months. Hooray!