Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: As we discussed on the phone this morning, I have recently installed extensive drought-resistant landscaping. I have also added wood chip mulch to prevent weeds. However, I'm concerned about how to maintain it weed-free as well as other areas in my garden. Our phone discussion covered many of the usual techniques to prevent weeds in this situation. You said that you would do some further review and possibly provide me with some more options.
UC MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your questions about weed control in your new landscape.
The first option is to put down a weed fabric (not plastic) on the edges of your landscaping to control the small, sneaky weeds that appear where the wood mulch tends to be thin. Once the fabric is installed, you can cover it back up with your wood mulch. This will stop the weeds from coming up on the edges of your pathways.
Another option we didn't discuss is using a weed flamer. Flamers require no chemicals, and don't result in groundwater contamination or chemical residues on garden. One plus for weed flamers is that they are usually considered an organic gardening method. For effective weed control, you can use flamers in spring and early summer as annual and perennial weeds emerge. Killing larger, mature plants requires more heat, so save time and fuel by flaming weeds when they're still young and tender. This is a good option for larger areas that need treatment.
You can Google ‘weed flamer' for local and online suppliers as well as additional safety guidance. The idea of weed flamers isn't to burn the plants, but to quickly pass over to apply the right amount of heat to cause the water in the weed cells to boil, causing the plant to atrophy and die. Torch remaining weeds once every two to three weeks in ongoing applications or as needed until the next frost. Flaming kills annual weeds completely but does not completely eradicate the roots of perennial weeds.
If you do decide to use a flamer, be sure to keep a water supply handy, and do not get the flame near anything flammable, especially your dry wood mulch back, for safety purposes. To be safe, you may need to pull the mulch back before using the flamer or drench the mulch first with water.
Here is a link to more (and extensive) information on weed control in your garden:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7441.html
Please don't hesitate to give us a call if you have additional questions!
Help Desk of the UC Master Gardener Program of Contra Costa County (SLH)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
Help From the Contra Costa Master Gardeners' Help Desk
Request: I'd like to reduce the use of tap water to irrigate my garden by recycling water from our washing machine. I understand this recycle/reuse water is called "graywater". Could you provide me some guidance on how to use graywater for my garden?
Response: Thank you for contracting Master Gardeners' Help Desk about using graywater in your garden. It's important that we learn how to use water more efficiently as drought conditions continue. I applaud your desire to use graywater as a tool to optimize our finite water resources. However, the use of graywater does come with some challenges.
Graywater is untreated waste water from clothes washers, showers, bathtubs, bathroom sinks and laundry tubs that is used for outdoor watering. In California, graywater does not include waste water from kitchen sinks, dishwashers, toilets, or laundry water from soiled diapers.
Graywater is also an option for irrigating your ornamentals but it should not be used to water root vegetables or any vegetables whose plant parts come into contact with the soil due to the potential that human pathogens might be present.
For more information on graywater installations, see the East Bay Municipal Utility District website http://www.ebmud.com/sites/default/files/pdfs/Graywater%20Fact%20Sheet.pdf and
https://www.ebmud.com/water-and-wastewater/water-conservation/watersmart-gardener.
When using graywater to irrigate plants, you should avoid using household products that contain sodium or sodium compounds, bleach or boron, as these can adversely affect plants and soils resulting in an alkaline soils condition not well tolerated by many plants. The UC article "Using Household Wastewater on Plants" http://vric.ucdavis.edu/pdf/fertilization_Householdwastewater.pdf describes the effect on plants of using products which contain boron and chlorine. The Greywater Action website http://greywateraction.org/contentgreywater?friendly?products/ provides a list of products available that are phosphate, sodium, chlorine and boron free. Although we can't recommend any specific brand, Greywater Action considers the following laundry products graywater friendly: Oasis Liquid Laundry Detergent, ECOS liquid detergent, Vaska and Dr. Bronners liquid soap. The Ecology Center in Berkeley also evaluated a number of laundry products for compatibility with graywater systems and the results are listed on their website: http://ecologycenter.org/factsheets/greywater?cleaning?products/ .
I hope this is helpful. Please feel free to contact us if you have any additional questions.
Thank you for doing your part to conserve water.
Contra Costa Master Gardeners' Help Desk
Note: The Contra Costa Master Gardener Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/