The rainy season is here and it is a good time to think about conserving and saving whatever befalls us this season. NOAA’s Climate Prediction Center gives a 70 percent chance of La nina conditions to develop this fall and a 55 percent chance that it will persist through the winter. La nina conditions are characterized by cooler than average temperatures in the Central Pacific with a resulting cool and moist jet stream in the northern states and a drier jet stream in the southern tier of states. Hence dry conditions in Southern California and perhaps snow and rain north of San Francisco. Of course long range forecasting is an iffy proposition, but is seems unlikely that our county will have a wet winter.
So, what can we do to help with the drought which is likely to continue? We are already over drafting aquifers, so conserving water remains an essential activity and of course water is becoming more expensive which also encourages conservation. One approach is to plant drought tolerant plants and also to group plants by their water needs so that the irrigation can be hydro-zoned for efficient water use based on the plant’s water requirements.
Recently at the UC Master Gardener’s Demo garden open house, I helped retro-fit a sprinkler system with a drip irrigation setup for one of the gardens. We plugged all the sprinkler heads except for two. There two were installed with filters and we attached ½ inch drip lines with built in emitters at 18 inch spacing. This will save a lot of water as it puts the water right at the plant. Less water, fewer weeds are the benefits. We used Netafim drip materials and for more information on using drip for landscapes you can find it here: http://www.netafimusa.com/landscape.
To keep water on your property where it does the most good rather than running down storm drains there are several things that you can do. Redirect water from driveways, walkways and hardscapes. This can be done by putting plastic or metal extensions and splashblocks on the downspout. This should also be done to keep water away from the house and foundation; see: https://www.thisoldhouse.com/how-to/how-to-drain-downspout-water-flow-away-house.
If hardscape have been constructed of porous concrete or porous asphalt materials this will allow water to drain through them. This is something to keep in mind if you replace any of these hardscapes in the future; see: http://www.wikihow.com/Reduce-Stormwater-Runoff-at-Your-Home. Water kept on your property can replenish underground storage essential to landscape plants.
Water harvesting has been done in many areas of the world for 4000 years. Bermuda which consists of seven small islands was settled in 1609 and has very little potable water from aquifers. Hence the settlers there harvested rainwater from roofs and catchment areas into tanks or underground cisterns which was necessary to provide for household needs. The farm house where I grew up had a cistern to collect rainwater from the roof and it was built in the 1880’s, before electric pumps were available to pump water. We are not in such dire straits yet, but we can harvest water from roofs to increase water available for garden and landscape use. Rain water that is harvested does not contain chlorine and is soft water, i.e., not containing calcium carbonate, iron or other compounds that make for hard water. Thus it is good water for plants.
There are many sources for barrels and tanks for water harvesting and it is possible to use a connected series of 50 gallon drums to harvest water from rooftops for gardens. Just do a google search on ‘rain barrels’ and you will see lots of choices. I was fortunate to purchase from a bulk water business, three 1000 gallon tanks for water harvesting. They were tanks with flaws that made them no longer fit for potable water, but work fine for collecting rainwater for garden uses. I use one for my entire spring greenhouse plant growing. The other two are used
for landscape watering. I also have eight 50 gallon drums next to my garden shed which receive water from my garden shed roof. Though a small shed, in a good year I will have 400 gallons of water to use for hand watering of seedlings in my vegetable garden. For more information on water harvesting see: http://www.conserve-energy-future.com/methods-of-rainwater-harvesting.php
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website: http://sjmastergardeners.ucanr.edu/CONTACT_US/