Rainwater Harvesting Workshop

The California Landscape Contractors Association: San Francisco Bay Area Education Committee presents our next informative workshop, Rainwater Harvesting for the Landscape Professional.

The residences of California use 5.6 million acre-feet of applied water annually and the growing population puts further strain on this limited resource. With the Bay Area now in its third drought year, we are finding ourselves having to do more with less. With landscape being the larger contributor to the strain on our water supplies, there is an increased need to incorporate water conservation strategies including; lawn reduction / removal, drought tolerant plantings, high efficiency irrigation systems, and rainwater catchment systems otherwise known as rainwater harvesting.
Some benefits of rainwater harvesting include having a reliable water source, the ability to store water for emergency purposes, on-site stormwater retention, and recharging of our aquifers. Additionally, with water rates on the rise, rainwater harvesting offers the opportunity to offset those rising water bills.
Given the increased demand, this rainwater harvesting event is expected to fill quickly so make your reservations now. The workshop will be an invaluable resource!
The event is set for Friday November 6, 2009 at Foothill College in Los Altos.

Your Landscapes Water Needs By Month

As temperature, humidity, and solar orientation change from month to month throughout the year, so do the needs of your landscape. It is my experience that the general population makes only two adjustments to the timers that control the amount of water the landscape receives. On and off. It is estimated more than 50% of landscape water is wasted by wind drift, evaporation and overwatering.
If you have an irrigation controller with a 'Seasonal Adjust' feature, this chart can help guide you towards performing the proper adjustments to conserve water. Note that July is the basis with watering times at 100%. Being this is September, your irrigation controller should only be about 60%. When the time comes for the controller to be set lower than 50%, my recommendation is to actually increase the duration at that point and reduce the days watered. The roots appreciate a deeper watering so watering deeper with less frequency is advantageous to the flora instead of small, shallow watering.


Wind drift is a term to describe overspray due to breezy/windy conditions. Many irrigation valves have an adjustment screw on them for flow control. Typically I find that new controllers are in the 'wide open' position. Most sprinklers, however, mist heavily when receiving that much pressure so dial it down to reduce evaporation, but make sure you still get adequate coverage. Adjusting the direction the sprinkler heads are aimed so that you are not watering your patio, driveway or sidewalk is helpful too. Changing the sprinklers themselves to a more efficient style like MP Rotators can help dramatically.
The time of day the irrigation controller comes on is important as well. The middle of day is the warmest so watering during that time only leads to increased evaporation. A large part of the water is lost. 40-50% of it I read in one article. Watering at night is better but often the ground is still warm leading to higher evaporation again. Additionally, many bad bacterias and molds like warm, moist conditions so start growing. These can harm your plants and grasses. My recommendation is early morning waterings, before the sun comes up. Between the hours of 4am and 6pm, the sun is not quite awake yet giving an opportunity for the ground to take in the water.

Decline of the Honey Bee

The reality of the important role the honey bee plays in our survival is delivered in the popular kids flick, Bee Movie. It is not just that the writer is telling a story but, as in many movies, there is a message being delivered. The problem is so severe in London that residents are encouraged to become bee keepers! Following is a portion of an interesting article I came across.

Bee populations are changing.
It's thought that there used to be 25 species of bumblebee in the UK, but now three are known to be extinct (Bombus cullumanus, B. pomorum and B. subterraneus).
Seven more species are listed on the Biodiversity Action Plan list as being in danger.

Honeybee numbers in the UK have fallen by up to 30% since 2007.

The 70% fall in Bumblebee numbers since the 1970s is largely attributed to the growth of industrial agricultural practices resulting in monocultures of crops, without suitable wildflower habitats for bees, and many other insects, to live on.
But some farmers are helping wildlife on their land and an increasing number of food products are now made from crops grown in a way that protects the countryside and provides food for bees.
Sadly, original wild honeybees (Apis mellifera mellifera) are now thought to be extinct in Britain, but literally millions of domestic strain honeybees are managed by beekeepers each year, which are familiar to all of us buzzing about parks and gardens.
Honeybees in Britain, however, are having a tough time and are increasingly affected by a range of problems including foulbrood; varroa mite; viral diseases and dysfunctional immune systems.
Colony collapse disorder, although widespread globally, does not yet seem to have arrived in the UK.
But just like bumblebees, honeybees are also suffering from the loss of widespread and varied foraging habitats, especially in the countryside.
The value of bees through pollination of crops is thought to be in the region of £1 billion a year and 35% of our own food crops are estimated to be directly dependent on honeybee pollination.
Bumblebees pollinate crops too, especially fruit like tomatoes and apples as well as other crops including oilseed rape and beans.
Some farmers even keep bumblebees in their greenhouses to pollinate crops that are grown all year round, and import southern European bumblebees raised in countries such as Slovakia and Holland.
The concern of conservationists is that this could potentially introduce further pest and disease risk to native British bumblebees.
Evidence in the US shows wild bumblebee numbers have collapsed since the 1990s - following the introduction of parasites carried by European species brought in to pollinate greenhouse crops such as tomatoes and peppers.
As well as decreasing numbers, there are also changes being observed where bumblebees live and how they behave.
The buff-tailed bumblebee (Bombus terrestris) for example has recently been recorded in flight in December and January along the south coast as far east as Ramsgate, as far north as Leicestershire and even North Wales.
This is really unusual, as typically only the queen bee overwinters in holes in the ground.
The suggestion is that global warming is affecting bee behaviour - which may, in turn, affect pollination, flowers, plant survival, fruit, crops and ultimately numerous species of wildlife...including us. -BBC London