What To Do About Shade?

Depending on the maturity of a landscape, shade is an issue that may grow worse over time.  Although low light can affect all plants, the most apparent changes will be in your turf.  Below is a picture that I took a few years ago as part of my research that show just how drastic areas of shade can be on plant growth:

These four pots contain St. Augustinegrass, shown after a week of growth under 0, 30, 60, and 90% shade.

 As mentioned in a previous post, the difference in growth is a result of signals to the plant to "grow out" of the stress (in this case shade).  This can lead to thin, weak growth which may cause a decline in plant health over time.

If you do have shaded areas in your landscape, they may have to be managed a little different for success.  These rules of thumb can help to keep these areas thriving:

• If shade is caused by plants (trees, etc), thinning of the canopy may increase available light.  Care should be taken that pruning is not so drastic that it damages the tree (usually no more than 1/3 of the canopy should be removed).
• If possible, reducing traffic in these areas can prevent additional thinning due to stress and potential compaction.
• Increase mowing height to the maximum recommended for the plant.  The more green, the more carbohydrates it can produce for survival.
• Try to reduce irrigation in these areas.  As moisture tends to remain for longer periods, this will aid in reducing the potential for disease and additional stresses.
• It may be hard, but reducing fertilization (particularly nitrogen!) will help to reduce excess growth that isn't beneficial to the plant.  Typically this should only be about 50-75% of what the rest of the lawn receives.

If the combination of these methods aren't working, a change in plant material may be necessary under dense shade conditions.  A more shade-tolerant species may be the trick, especially if plant growth (and shade!) is expected to increase in the future.

Cosmetic Pesticide Bans: What's Coming?

As a graduate student, a good portion of my research dealt with non-synthetic control of weeds in landscapes.  This included evaluating cultural practices and "organic" products for their efficacy.  While researching the topic, I became acquainted with the Cosmetic Pesticide Ban laws enacted across most of our northern neighbor, Canada.  These laws restrict the use of up to around 240 pesticide products, which include approximately 50 active ingredients. What started in a few municipalities in the early 2000's became a province-wide law banning the use of these pesticides for cosmetic purposes in Quebec in 2006.  These include public and private applications including parks, public spaces, and all commercial and residential lawns and landscapes. In the decade since, these bans continued to spread across the majority of the other Canadian provinces.  They include:

• Ontario (2008)
• Nova Scotia (2011)
• New Brunswick (2009) (2,4-D only)
• Prince Edward Island (2010) (2,4-D only)
• Newfoundland (2012) (2,4-D and other growth regulators)
• Manitoba (2015)

Alberta uncoupled herbicide/fertilizer products in 2010 (elimination sale of "weed and feeds"), and British Columbia enacted integrated pest management (IPM) requirements in 2013.  In addition, both of these provinces had many municipalities enact local pesticide bans.  I included this history in many of my presentation to highlight the speed and scope of which these bans can potentially have.

Last year, the city of Irvine became the first in southern California to pass restrictions on pesticide use in public places.  Since then, other cities in Orange County have either passed or discussed similar laws, including San Juan Capistrano, Tustin, Huntington Beach, and Costa Mesa.  Pressure is also being placed on HOAs to eliminate glyphosate (Roundup) from their management programs.  

Will these bans continue to spread?  If the situation is compared to similar scenarios in other states (such as fertilizer bans and blackouts in Florida, Michigan, New York, etc.) the answer will be yes.  Even though politics may be different in California compared to Canada's provinces, the 2020's may see proposals for state-wide ban of "cosmetic" pesticides for lawns and landscapes.

Pesticide bans could prohibit the use of the most common herbicides available for the landscape, including glyphosate and 2,4-D

Fall Effects on Turfgrass

The fall is a beautiful time of year (football season doesn't hurt either), but it does have some interesting effects of turfgrass.  Cooler temperatures at night can cause warm-season grass growth to slow, while conditions optimize for cool-season species.  Along with temperature, day length also begins to shorten.  This means that less light is available for plant use, which can be reduced even further by extra shade cast by buildings (north side) and other plants.

What can happen during these conditions?  Moisture from dew or irrigation may take longer to evaporate from leaf surfaces, creating an ideal environment for disease outbreaks (which can vary depending on the grass species).  Low light can also trigger changes in the turf itself, leading to elongated leaf blades (which are also thinner).  This growth can lead to scalping, which can affect turf health and aesthetic.  If identified early, many of these issues can be preventatively treated.  Fungicides and plant growth regulators can be used to target problematic areas.  Cultural practices should also be adjusted, including raising the height on mower decks.  Depending on the local climate, these factors should continue to be monitored until dormancy (warm-season) or changes in growth rate (cool-season).

Scalping on a kikuyugrass lawn

Welcome to the Landscape Blog!

Welcome!  We hope to use this blog as a means to update the landscape community on important issues, tips and advice, and management strategies.  We welcome any comments and encourage feedback on these posts.  If you have any topics that you would like covered, let us know and we will try to address it in future articles.

To introduce myself, my name is Brian Glenn.  While I always liked mowing lawns, my interest in landscapes really accelerated as a college student with a summer job pruning shrubs at Brigham Young University.  That fall, I enrolled in "Living with Plants", and from there I was hooked.  I switched my major to Landscape Management, and spent the rest of my undergraduate working and repairing sports turf around campus.  Feeling like there was so much more to learn, I pursued graduate work at the University of Florida, where I was exposed to all things warm season (as well as a never-ending supply of weeds!).  By the time I was done, I had finished with a Ph.D. in horticulture.  I then came back to southern California, working in technical services in vegetation management. While I am in constant awe about how much there is to learn about the natural world around us, I want to use the knowledge I have gained to provide solutions in the landscaping industry.  Few things compare with the satisfaction of solving a complex problem and seeing results!

Myself as a graduate student (I'm sure imparting a lot of turfgrass wisdom...)